Seaweeds of the South African South Coast

Book 6: Phylum Rhodophyta (Red Seaweeds)
Order Ceramiales (Part 1) to Order Hapalidales

By

Robert James Anderson
University of Cape Town and Department of Agriculture, Forestry and Fisheries, South Africa

Herre Stegenga
Naturalis, Netherlands

John Joseph Bolton
University of Cape Town, South Africa

2020

Herre Stegenga's line drawings from Seaweeds of the South African West Coast
(Contributions from the Bolus Herbarium, Vol 18, 1997) are reproduced with permission.  

Copyright © 2020 Robert Anderson et al. All rights reserved.

Copyright © 2020 by Robert Anderson et al.
All rights reserved. No part of this publication
may be reproduced, distributed, or transmitted in any
form or by any means, including photocopying, recording,
or other electronic or mechanical methods,
without the express written permission of the authors
except for the use of brief quotations in a book review.

Printed in the Republic of South Africa

First Edition, 2020

ISBN 0-0000000-0-0

University of Cape Town,
Private Bag X3,
Rondebosch 7701,
South Africa
www.uct.ac.za

Ordering Information:
This eBook can be downloaded free from: southafrseaweeds.uct.ac.za/

INTRODUCTION TO THE RHODOPHYTA (red seaweeds)

The Phylum Rhodophyta is commonly known as the ‘red algae’. Most species of red algae are seaweeds, but there are also many different forms, including single-celled organisms on soil and various forms in rivers and lakes. A fossil red alga from Canada, Bangiomorpha pubescens, is the oldest known record of eukaryotic life on earth, dated at around 1200 million years old. Yoon et al. (2017) list 7 classes of Rhodophyta, although almost all the seaweed species here are in the class Florideophyceae, with very few exceptions such as species of Porphyra (Bangiophyceae) and Stylonema (Stylonematophyceae). Red seaweeds grow in all marine environments where there is sufficient light, from the intertidal to over 200m depth in very clear tropical seas. The larger species are smaller than the largest brown algae, with a maximum of around 3m worldwide. The largest recorded in South Africa are specimens of Pachymenia orbitosa on the west coast, which grow to around 2m. On the south coast, the largest species are not more than around 50cm long. Red seaweeds make up ca. 70% of the seaweed species present in South Africa.

The common name ‘red algae’ can be confusing for some members of this group. Most species of red algae look various shades of red (from dark burgundy to pink), due to the dominance of the red-coloured pigment phycoerythrin. The Rhodophyta, however, contain other pigments including chlorophylls (green), carotenoids (yellow to brown) and phycocyanin (blue-green). Sometimes these other pigments dominate in the plant or species, for example many freshwater ‘red algae’ are blue-green in colour. Among south coast seaweeds, one of the most abundant , Hypnea spicifera, is often almost completely green, with a few darker reddish parts where it is shaded at the base. High intertidal species such as Porphyra and Bostrychia often appear blackish. Also, some bladed shallow water species, which occur in high light, appear more brownish than reddish. It should be remembered that most species of seaweeds on this coast are red algae, and if plants are reddish in some small part they are likely to be members of the Rhodophyta.

The red seaweeds of the South African south coast are divided here into four ebooks based on their taxonomic position (hence evolutionary relationships), using data from Algaebase.org (Guiry and Guiry 2016).This series contains keys to the species within each genus, but no key or picture guide to higher-level groups of taxa, because this is often not possible by simple observation. The high-level taxa (sub-phyla, classes, orders) were traditionally defined using microscopic characteristics, and nowadays mostly by DNA sequencing. In marine guidebooks containing a small selection of common species, they are often arranged in ‘form groups’, which although useful, do not follow the evolutionary relationships between them (e.g. Branch et al. 2017). Such guidebooks remain a useful adjunct to the present series.

The forms of red seaweeds range from small threadlike filaments, one to many cells wide, to various sizes of branched or unbranched, cylindrical to leafy plants. Most of the species diversity in the red algae on the south coast is comprised of small filamentous species, many of which grow attached to larger algae (epiphytes). These are mostly in the families Ceramiaceae (e.g. Ceramium), Rhodomelaceae (e.g. Polysiphonia, Pterosiphonia, Herposiphonia) and Callithamniaceae (e.g. Callithamnion). A few are crusts, which form a very thin layer growing closely attached as a thin ‘skin’ over the surface of rocks (e.g. Hildenbrandia rubra). A particularly important form group of red seaweeds is the coralline red algae, which deposit significant amounts of calcium carbonate in their cell walls, forming a hard, internal skeleton. Many of these exists as crusts, and these have been fairly well studied in South Africa (Maneveldt et al. 2016). The crustose coralline red algae require specific techniques to collect, identify and study, including chiselling them off the rock and dissolving away the calcium carbonate with dilute acid to reveal the critical microscopic structures. They are not included in these ebooks. The other form group of coralline algae is known as geniculate (articulated or jointed) corallines and they exist as upright seaweeds (see Book 4 in this series). They consist of calcified segments (genicula), separated by non-calcified tissue (intergenicula) which allows flexibility (e.g. species of Amphiroa, Arthrocardia, Jania). Many of these geniculate corallines are particularly difficult to identify to species.

Red seaweeds are ecologically dominant on many local seashores. Porphyra is not as abundant on the south coast as the west coast, but patches of Porphyra agulhensis, where present, are the uppermost seaweeds in the south coast intertidal, with Bostrychia intricata in upper shore crevices. Many south coast seashores tend to be animal dominated (limpets and barnacles) in the mid-intertidal, with most seaweed diversity in rock pools. In the lower intertidal and shallow subtidal there is often dominance of a wide variety of red seaweeds. In most western areas of the south coast, this are often various species of Laurencia, Hypnea (especiallyHypnea spicifera) and Plocamium (especially Plocamium corallorhiza, one of the most abundant red seaweeds in South Africa). Further east there is an increasing dominance of geniculate coralline red seaweeds (species of Amphiroa, Arthrocardia etc.: Kogame et al. 2016).

Red seaweeds have the most complicated life cycles in the algae, and the reproductive structures are often important in species identification. Most species exist as three different types of plants on the seashore:

- Sporophytes: In the Florideophyceae usally called ‘tetrasporophytes’ as they mostly produce tetraspores in packets of four (see Callithamnion tripinnatum). A few produce more than four, such as the polysporangia of Pleonosporium filicinum.

- Female gametophytes: A few larger seaweeds have visible rounded structures on the surface called ‘cystocarps’, which produce carpospores (e.g. Martensia elegans or Sarcodia dentata). More often these structures can only be seen by microscopic examination (e.g. Platysiphonia delicata), sometimes after cutting a cross-section of the tissue in bladelike species.

- Male gametophytes: These are often known only as the plants without tetraspores or cystocarps, as the male reproductive structures can be difficult to see even with a compound microscope. In some small species, they are easier to see under the microscope, but may not be easy to find (e.g. Ceramium glanduliferum).

The three different plants with their respective reproductive structures are clearly shown in the micrographs of Lophosiphonia capensis. Many species of red algae have populations which are dominated by tetrasporophytes, and a few (especially members of the Gigartinaceae) are dominated by gametophytes.

Some forms of red algae, particularly fine filamentous seaweeds and some leaflike blades, cannot be identified to species without microscopic study at 400x magnification. The descriptions here thus contain microscope pictures of filaments or sections of blades wherever possible.

SYSTEMATIC CLASSIFICATION OF SOUTH COAST RHODOPHYTA

Note: the list below of taxonomic placing of genera was revised in November 2016, using AlgaeBase. The higher-level taxonomic placing of certain genera may differ from that shown under each genus or species on this website, because some of these have not yet been updated. When in doubt see AlgaeBase.org

BOOK 3

CLASS BANGIOPHYCEAE

Sub Class Bangiophycidae

Order Bangiales

FAMILY BANGIACEAE
      Porphyra capensis Kützing
      Porphyra sp. 1

CLASS STYLONEMATOPHYCEAE

Order Stylonematales

FAMILY STYLONEMATACEAE
      Stylonema alsidii (Zanardini) Drew
      Stylonema cornu-cervi Reinsch (see under S. alsidii)

CLASS COMPSOPOGONOPHYCEAE

Order Erythropeltidales

FAMILY ERYTHROTRICHIACEAE
      Erythrotrichia bertholdii  Batters
      Erythrotrichia platyphylla Stegenga, Engledow, Bolton & Anderson
      Erythrotrichia welwitschii (Ruprecht) Batters
      Membranella africana Stegenga, Bolton & Anderson
      Porphyrostromium boryanum (Montagne) P.C. Silva in Silva, Basson & Moe
      Sahlingia subintegra (Rosenvinge) Kornmann

CLASS FLORIDEOPHYCEAE

Sub Class Hildenbrandiophycidae

Order Hildenbrandiales

FAMILY HILDENBRANDIACEAE
      Hildenbrandia lecanellierii Hariot
      Hildenbrandia rubra (Sommerfelt) Meneghini

Sub Class Nemaliophycideae

Order Acrochaetiales

FAMILY ACROCHAETIACEAE
      Acrochaetium brebneri (Batters) G. Hamel
      Acrochaetium catenulatum M.A.Howe
      Acrochaetium hlulekaense Stegenga
      Acrochaetium moniliforme (Rosenvinge) Børgesen
      Acrochaetium reductum (Rosenvinge) G.Hamel
      Acrochaetium tenuissimum (F.S.Collins) Papenfuss

Order Colaconematales

FAMILY COLACONEMATACEAE
      Colaconema caespitosum (J.Agardh) Jackelman, Stegenga & J.J.Bolton
      Colaconema codicola (Børgesen) H.Stegenga, J.J.Bolton, & R.J.Anderson
      Colaconema daviesii (Dillwyn) Stegenga
      Colaconema dictyotae (Collins) I.-K.Hwang & H.-S.Kim
      Colaconema endophyticum (Batters) J.T.Harper & G.W.Saunders
      Colaconema interpositum (Heydrich) H.Stegenga, J.J.Bolton & R.J.Anderson
      Colaconema nemalionis (De Notaris ex L. Dufour) Stegenga
      Colaconema pectinatum (Kylin) J.T.Harper & G.W.Saunders
      Colaconema seriatum (Børgesen) Stegenga
      Colaconema spongicola (Weber-van Bosse) Woelkerling

Order Nemaliales

FAMILY GALAXAURACEAE
      Dichotomaria diesingiana (Zanardini) Huisman, J.T. Harper & G.W. Saunders
      Dichotomaria hommersandii L. Liu & S-M Lin
      Dichotomaria obtusata (J. Ellis & Solander) J.V. Lamouroux
      Dichotomaria tenera (Kjellman) Huisman, J.T. Harper & G.W. Saunders

FAMILY HELMINTHOCLADACEAE
      Helminthocladia australis Harvey
      Helminthora furcellata (Reinbold in Tyson) Martin

FAMILY SCINAIACEAE
      Nothogenia erinacea (Turner) Parkinson
      Nothogenia ovalis (Suhr) Parkinson
      Scinaia capensis (Setchell) Huisman
      Scinaia salicorniodes (Kützing) J. Agardh

Order Gelidiales

FAMILY GELIDIACEAE
      Gelidium abbottiorum R. Norris
      Gelidium arenarium Kylin
      Gelidium capense (S.G. Gmelin) P.C. Silva in P.C. Silva, E.G. Meñez, & Moe
      Gelidium crinale (Hare ex Turner) Gaillon
      Gelidium declerckii E. M. Tronchin in Millar and Freshwater
      Gelidium foliaceum (Okamura) E. M. Tronchin
      Gelidium isabelae W.R.Taylor
      Gelidium micropterum Kützing
      Gelidium pristoides (Turner) Kützing
      Gelidium pteridifolium R.E. Norris, Hommersand and Fredericq
      Gelidium reptans (Suhr) Kylin
      Pterocladiella caespitosa (Kylin) Santelices
      Pterocladiella caloglossoides (M.A. Howe) Santelices
      Ptilophora diversifolia (Suhr) Papenfuss
      Ptilophora pinnatifida J. Agardh

Order Palmariales

FAMILY RHODOTHAMNIELLACEAE
      Rhodothamniella floridula (Dillwyn) Feldmann in T.Christensen

FAMILY MEIODISCACEAE
      Meiodiscus concrescens (K.M.Drew) P.W.Gabrielson in Gabrielsen et al.

Sub Class Rhodymeniophycidae

Order Bonnemaisoniales

FAMILY BONNEMAISONIACEAE
      Asparagopsis armata Harvey
      Asparagopsis taxiformis (Delile) Trevisan de Saint-Léon
      Delisea flaccida (Suhr) Papenfuss

Order Peyssonneliales

FAMILY PEYSSONNELIACEAE
      Peyssonnelia atropurpurea Crouan & Crouan
      Peyssonnelia replicata Kützing
      Sonderopelta capensis (Montagne) D.M. Krayesky

Order Halymeniales

FAMILY HALYMENIACEAE
      Codiophyllum natalense J. E. Gray
      Cryptonemia natalensis (J. Agardh) Chiang
      Grateloupia capensis O. De Clerck ex De Clerck, Gavio, Fredericq, Barbara & Coppejans
      Pachymenia cornea (Kützing) Chiang
      Pachymenia ulvoidea (F. Schmitz) L. Russell in Russell, Hurd, Nelson & Broom
      Polyopes constrictus (Turner) J. Agardh
      Prionitis filiformis Kylin
      Prionitis nodifera (Hering) Barton

Order Gracilariales

FAMILY GRACILARIACEAE
      Gracilaria aculeata (Hering) Papenfuss
      Gracilaria beckeri (J.Agardh) Papenfuss
      Gracilaria capensis F. Schmitz ex Mazza
      Gracilaria denticulata F. Schmitz ex Mazza
      Gracilaria gracilis (Stackhouse) M.Steentoft, L.M.Irvine & W.F.Farnham
      Gracilariopsis funicularis Iyer, Bolton & Coyne
      Gracilariopsis longissima (S.G.Gmelin) M.Steentoft, L.M.Irvine & W.F.Farnham

FAMILY PTEROCLADIOPHILACEAE
      Gelidiocolax margaritoides (M.T.Martin & M.A.Pocock) K.-C.Fan & Papenfuss

BOOK 4

Order Gigartinales

FAMILY KALLYMENIACEAE
      Callophyllis variegata (Bory de Saint-Vincent) Kützing
      Pugetia harveyana (J. Agardh) R.E. Norris
      Pugetia porphyroidea (F. Schmitz ex Holmes) R.E. Norris
      Thamnophyllis pocockiae R.E. Norris

FAMILY GYMNOPHLOEACEAE
      Schizymenia apoda (J. Agardh) J. Agardh

FAMILY PHACELOCARPACEAE
      Phacelocarpus oligacanthus Kützing
      Phacelocarpus tortuosus Endlicher & Diesing

FAMILY SOLIERIACEAE
      Callophycus densus (Sonder) Kraft
      Callophycus tridentifer Kraft
      Rhabdonia natalensis Reinbold

FAMILY ARESCHOUGIACEAE
      Erythroclonium corallinum (Suhr) Holmes

FAMILY CAULACANTHACEAE
      Catenella nipae Zanardini
      Caulacanthus ustulatus (Turner) Kützing
      Heringia mirabilis (C. Agardh) J. Agardh

FAMILY CYSTOCLONIACEAE
      Calliblepharis fimbriata (Greville) Kützing
      Hypnea arenaria Kylin
      Hypnea intricata Kylin
      Hypnea musciformis (Wulfen) J. V. Lamouroux
      Hypnea rosea Papenfuss
      Hypnea spicifera (Suhr) Harvey
      Hypnea tenuis Kylin
      Hypnea viridis Papenfuss
      Rhodophyllis reptans (Suhr) Papenfuss

FAMILY RHIZOPHYLLIDACEAE
      Portieria hornemannii (Lyngbye) P.C. Silva in P.C. Silva, Meñez & Moe
      Portieria tripinnata (Hering) De Clerck in De Clerck, Tronchin & Schils

FAMILY PHYLLOPHORACEAE
      Gymnogongrus glomeratus J. Agardh
      Gymnogongrus polycladus (Kützing) J. Agardh
      Gymnogongrus tetrasporifer Papenfuss in R.J.Anderson & Bolton

FAMILY GIGARTINACEAE
      Chondracanthus acicularis (Roth) Fredericq in Hommersand, Guiry, Fredericq & Leister
      Gigartina insignis (Endlicher & Diesing) Schmitz in Barton
      Gigartina minima Kylin
      Gigartina paxillata Papenfuss
      Gigartina pistillata (S.G. Gmelin) Stackhouse
      Gigartina polycarpa (Kützing) Setchell & Gardner

Order Plocamiales

FAMILY PLOCAMIACEAE
      Plocamiocolax papenfussiana Martin & Pocock
      Plocamium beckeri Simons
      Plocamium corallorhiza (Turner) J.D. Hooker & Harvey
      Plocamium cornutum (Turner) Harvey
      Plocamium glomeratum J. Agardh
      Plocamium maxillosum (Poiret) J.V. Lamouroux
      Plocamium rigidum Bory de Saint-Vincent in Bélanger & Bory de Saint-Vincent
      Plocamium suhrii Kützing
      Plocamium telfairiae (W. J. Hooker & Harvey) Harvey ex Kützing

FAMILY SARCODIACEAE
      Sarcodia dentata (Suhr) R. E. Norris
      Trematocarpus flabellatus (J.Agardh) De Toni

Order Rhodymeniales

FAMILY RHODYMENIACEAE
      Botryocladia beckeriana (Holmes) Papenfuss
      Botryocladia madagascariensis G. Feldmann
      Botryocladia pienaarii RE Norris
      Ceratodictyon variabile (Greville ex J. Agardh) RE Norris
      Erythrymenia obovata Schmitz ex Mazza
      Rhodymenia capensis J. Agardh
      Rhodymenia holmesii Ardissone
      Rhodymenia natalensis Kylin

FAMILY CHAMPIACEAE
      Champia compressa Harvey
      Champia parvula (C. Agardh) Harvey
      Chylocladia capensis Harvey

FAMILY HYMENOCLADIACEAE
      Hymenocladia kallymenioides (Holmes) F. Schmitz

FAMILY LOMENTARIACEAE
      Lomentaria amplexans RE Norris
      Lomentaria corallicola Børgesen
      Lomentaria diffusa Stegenga, Bolton & Anderson

BOOK 5

Order Ceramiales (in part)

FAMILY CALLITHAMNIACEAE
      Callithamnion collabens (Rudolphi) L.McIvor & Maggs
      Callithamnion cordatum Børgesen
      Callithamnion granulatum (Ducluzeau) C. Agardh
      Callithamnion hookeri (Dillwyn) S.F. Gray
      Callithamnion stuposum Suhr
      Callithamnion tripinnatum C. Agardh
      Callithamnion sp. 1
      Callithamnion sp. 2
      Crouania attenuata (C. Agardh) J. Agardh
      Crouania francescoi Cormaci, G Furnari et Scammacca
      Euptilota mollis (Wollaston) O. De Clerck
      Heteroptilon pappeanum (Kützing) Hommersand in Hommersand, D.W. Freshwater, J. López-Bautista, & S. Fredericq

FAMILY CERAMIACEAE
      Acrothamnion preissii (Sonder) E.M. Wollaston
      Amoenothamnion lycopodioides Stegenga
      Antithamnion diminuatum Wollaston
      Antithamnion hubbsii E.Y. Dawson
      Antithamnionella spirographidis (Schiffner) E.M. Wollaston
      Antithamnionella ternifolia (J.D.Hooker & Harvey) Lyle
      Antithamnionella tormentosa Stegenga
      Antithamnionella verticillata (Suhr) Lyle
      Antithamnionella sp.
      Bornetia repens Stegenga
      Callithamniella capensis  Simons
      Callithamniella tingitana (Schousboe ex Bornet) Feldmann-Mazoyer
      Carpoblepharis flaccida (J.V.Lamouroux) Kützing
      Centroceras spp.
      Ceramium aff. callipterum Mazoyer
      Ceramium arenarium Simons
      Ceramium camoui Dawson E.Y.Dawson
      Ceramium centroceratiforme Simons
      Ceramium glanduliferum Kylin
      Ceramium graecum/lenticulare complex
      Ceramium juliae A.J.K.Millar
      Ceramium obsoletum C. Agardh
      Ceramium planum Kützing
      Ceramium poeppigianum Grunow
      Ceramium tenerrimum (G. Martens) Okamura
      Ceramium sp. 1
      Ceramium sp. 2
      Ceramium sp. 3
      Compsothamnionella sciadophila Stegenga
      Episporium centroceratis Möbius
      Gayliella dawsonii (= Ceramium dawsonii A.B. Joly)
      Gayliella papenfussiana (= Ceramium papenfussianum Simons)
      Gayliella transversalis (Collins et Hervey) T.O. Cho et Fredericq
      Laurenciophila minima Stegenga
      Microcladia exserta  M.J.Wynne
      Microcladia gelidii R.H.Simons
      Perischelia glomulifera (J.Agardh) J.Agardh ex Kylin
      Pterothamnion recurvatum (Wollaston) Athanasiadis & Kraft
      Pterothamnion sp.
      Ptilothamnion codicola (E.Y.Dawson) I.A. Abbott
      Ptilothamnion goukammae Stegenga, Bolton & R.J. Anderson
      Ptilothamnion polysporum Gordon-Mills & Wollaston in Wollaston
      Scageliopsis tsitsikammae Stegenga, R.J. Anderson & J.J. Bolton
      Syringocolax macroblepharis Reinsch
      Zonariophila semiendophytica Stegenga et Kemperman

FAMILY DASYACEAE
      Dasya echinata Stegenga, Bolton & Anderson
      Dasya scoparia Harvey ex J. Agardh
      Dasya sp. 1
      Dasya sp. 2
      Dasya sp. 3
      Dipterocladia pinnatifolia (Suhr) Y.S.M. De Jong
      Heterosiphonia arenaria Kylin
      Heterosiphonia crispa (Suhr) Falkenberg
      Heterosiphonia dubia (Suhr) Falkenberg

FAMILY DELESSERIACEAE
      Acrosorium acrospermum (J. Agardh) Kylin
      Acrosorium ciliolatum (Harvey) Kylin
      Acrosorium maculatum (Sonder ex Kützing) Papenfuss
      Apoglossum ruscifolium (Turner) J. Agardh
      Apoglossum spathulatum (Sonder) Womersley and Shepley
      Bartoniella crenata Kylin
      Caloglossa leprieurii (Montagne) G. Martens
      Gonimophyllum africanum Martin and Pocock
      Holmesia capensis J Agardh
      Hypoglossum imperfectum Stegenga, Anderson and Bolton
      Martensia elegans Hering
      Neoholmesia natalensis M. J. Wynne
      Nienburgia pinnatifida (Suhr) Papenfuss
      Nienburgia serrata (Suhr) Papenfuss
      Papenfussia laciniata (Harvey) Kylin
      Papenfussia minuta Kylin
      Platysiphonia delicata (Clemente y Rubio) Cremades
      Taenioma perpusillum (J. Agardh) J. Agardh
      Valeriemaya seagriefii De Clerck, Wynne and Stegenga

FAMILY INKYULEEACEAE
      Inkyuleea beckeri (F.Schmitz ex Mazza) H.-G.Choi, Kraft & G.W.Saunders

BOOK 6

Order Ceramiales (in part)

FAMILY RHODOMELACEAE
      Acanthophora spicifera (M.Vahl) Børgesen
      Aiolocolax pulchellus M.A.Pocock
      Aphanocladia ecorticata Stegenga, R.J.Anderson & Bolton
      Bostrychia harveyi Montagne
      Bostrychia intricata (Bory de Saint-Vincent) Montagne
      Bostrychia moritziana (Sonder ex Kützing) J.Agardh
      Bostrychia radicans (Montagne) Montagne
      Bostrychia simpliciuscula Harvey ex J.Agardh
      Bostrychia tangatensis Post
      Bostrychia tenella (Lamouroux) J. Agardh
      Chondria armata (Kützing) Okamura
      Chondria capensis (Harvey) Askenasy
      Chondria dasyphylla (Woodward) C.Agardh
      Chondria sp.
      Colacopsis velutina (M.T.Martin & M.A.Pocock) R.E.Norris
      Dasyclonium incisum (J.Agardh) Kylin
      Dasyclonium palmatifidum (Grunow) Scagel
      Dictyomenia stephensonii Papenfuss
      Hawaiia sp.
      Herposiphonia clavata M.J. Wynne
      Herposiphonia didymosporangia Stegenga and Kemperman
      Herposiphonia falcata
      Herposiphonia prorepens (Harvey) F. Schmitz
      Herposiphonia secunda (C.Agardh) Ambronn
      Herposiphonia secunda f. tenella (C.Agardh) M.J.Wynne
      Janczewskia meridionalis M.T.Martin & M.A.Pocock
      Laurencia alfredensis Francis, Bolton, Mattio & R.J. Anderson
      Laurencia complanata (Suhr) Kützing
      Laurencia cf corymbosa J.Agardh
      Laurencia digitata Francis, Bolton, Mattio & R.J. Anderson
      Laurencia flexuosa (Suhr) Kützing
      Laurencia glomerata (Kützing) Kützing
      Laurencia griseaviolacea M.J. Wynne
      Laurencia multiclavata Francis, Bolton, Mattio & R.J. Anderson
      Laurencia natalensis Kylin
      Laurencia pumila (Grunow) Papenfuss
      Laurencia pumila var. dehoopiensis Francis, Bolton, Mattio & R.J. Anderson
      Lophosiphonia capensis (Kylin) R.E.Norris
      Lophosiponia reptabunda (Suhr) Kylin
      Microcolax africanus M.T.Martin & M.A.Pocock
      Onychocolax polysiphoniae M.A. Pocock
      Ophidocladus simpliciusculus (P.L.Crouan & H.M.Crouan) Falkenberg in Schmitz & Falkenberg
      Osmundaria serrata (Suhr) R.E.Norris
      Pachychaeta brachyarthra (Kützing) Trevisan
      Pachychaeta cryptoclada Falkenberg
      Placophora binderi (J.Agardh) J.Agardh
      Placophora monocarpa (Montagne) Papenfuss
      Kentrophora natalensis (J.Agardh) S.M.Wilson & Kraft in R.J.F. Henderson, S.M. Wilson & Kraft
      Neosiphonia sertularioides (Grateloup) K.W. Nam & P.J. Kang
      Polysiphonia foetidissima Cocks ex Bornet
      Polysiphonia incompta Harvey
      Polysiphonia kowiensis Stegenga, J.J. Bolton & R.J. Anderson
      Polysiphonia namibiensis Stegenga et Engledow in Stegenga, Bolton et Anderson
      Polysiphonia scopulorum Harvey
      Polysiphonia sp. 1
      Polysiphonia sp. 2
      Polysiphonia sp. 3 (note only – see under P. incompta)
      Polysiphonia sp. 4
      Polysiphonia subtilissima  Montagne (note only – see under genus description)
      Polyzonia elegans Suhr
      Pterosiphonia cloiophylla (C.Agardh) Falkenberg in Schmitz & Falkenberg
      Pterosiphonia spinifera (Kützing) Ardré
      Pterosiphonia stangerii (J.Agardh) Falkenberg
      Pterosiphonia stegengae Savoie & G.W.Saunders
      Pterosiphonia sp.
      Rhodomelopsis africana M.A.Pocock
      Streblocladia corymbifera (C.Agardh) Kylin
      Streblocladia tenuissima M.A.Pocock
      Streblocladia sp.
      Symphyocladia marchantioides (Harvey) Falkenberg in Schmitz & Falkenberg
      Tayloriella tenebrosa (Harvey) Kylin

FAMILY SPYRIDIACEAE
      Spyridia cupressina Kützing
      Spyridia filamentosa (Wulfen) Harvey in Hooker
      Spyridia horridula F. Schmitz ex J. Agardh
      Spyridia hypnoides (Bory) Papenfuss
      Spyridia plumosa F. Schmitz ex J. Agardh

FAMILY WRANGELIACEAE
      Anotrichium furcellatum (J. Agardh) Baldock
      Anotrichium tenue (C. Agardh) Nägeli
      Dasyphila cryptocarpa (Holmes) F. Schmitz
      Griffithsia confervoides Suhr
      Griffithsia subbiconica Stegenga
      Griffithsia sp.
      Gymnothamnion elegans (Schousboe ex C. Agardh) J. Agardh
      Gymnothamnion elegans var. bisporum Stegenga
      Haloplegma duperreyi Montagne
      Pleonosporium callicladum R.E. Norris
      Pleonosporium filicinum (Harvey ex J. Agardh) De Toni
      Pleonosporium harveyanum (J. Agardh) De Toni
      Shepleya elixithamnia Gordon-Mills & R.E. Norris
      Spermothamnieae indet.
      Spongoclonium caribaeum (Børgesen) M.J.Wynne
      Stegengaea capensis (Stegenga) Alongi, Cormaci & G.Furnari
      Tiffaniella cymodoceae (Børgesen) E.M.Gordon
      Tiffaniella schmitziana (Barton) Bolton et Stegenga
      Vickersia baccata (J. Agardh) Karsakoff
      Wrangelia purpurifera (Harvey) J. Agardh

Sub Class Corallinophycidae

Order Corallinales

FAMILY CORALLINACEAE

Crustose corallines (non-geniculate) species: these are not covered here. See Maneveldt, Chamberlain & Keats 2008. A catalogue with keys to the non-geniculate coralline algae (Corallinales, Rhodophyta) of South Africa. South African Journal of Botany 74(4):555-566.

SUB-FAMILY CORALLINOIDEAE (articulated, geniculate taxa)
      Amphiroa anceps (Lamarck) Decaisne
      Amphiroa beauvoisii  Lamouroux
      Amphiroa bowerbankii Harvey
      Amphiroa capensis Areschoug in J. Agardh
      Amphiroa ephedraea (Lamarck) Decaisne
      Amphiroa rigida J.V. Lamouroux
      Arthrocardia carinata (Kützing) Johansen
      Arthrocardia corymbosa (Lamarck) Decaisne
      Arthrocardia duthieae Johansen
      Arthrocardia flabellata (Kützing) Manza
      Arthrocardia palmata (J. Ellis & Solander) J.E. Areschoug in J. Agardh
      Corallina berteroi Montagne ex Kützing
      Corallina sp. 1
      Jania adhaerens Lamouroux
      Jania capillacea Harvey
      Jania cultrata (Harvey) J. H. Kim, Guiry & H.-G. Choi
      Jania prolifera (J.V.Lamouroux) J.H.Kim, Guiry & H.-G.Choi
      Jania sagittata (J.V.Lamouroux) Blainville
      Jania subulata (Ellis & Solander) Sonder
      Jania verrucosa Lamouroux

SUB-FAMILY MASTOPHOROIDEAE
      Metamastophora flabellata (Sonder) Setchell

Order Hapalidales

FAMILY HAPALIDACAE
      Choreonema thuretii (Bornet) F.Schmitz

Order Ceramiales

Family Rhodomelaceae

Acanthophora spicifera (M.Vahl) Børgesen 1910: 201, figs 18-19

Plants brownish-red to yellowish, up to 20 cm tall, spiny and rather brittle, comprising several erect, branched axes arising from a lobed basal disc. Axes heavily corticated, cylindrical, 0.3 – 3 mm in diameter; main axes smooth, with few or no spines, branching radial to irregular, upper ends of branches covered with spirally-arranged short (up to 0.5 mm) spines often with trichoblasts at tips. Five pericentral cells surrounded by cortical cells; outer cortical cells rather elongated. Tetrasporangia in rows in short spinose swollen branchlets, about 45-75 µm tetrahedrally divided. Cystocarps solitary, urn-shaped, in axils of spinose branchlets, up to 1 mm diameter.

Collections, ecology and regional distribution

Recorded from Algoa Bay to northern KwaZulu-Natal. (36-58). On hard substrata in the shallow subtidal zone of rather sheltered areas and in some estuaries.

World distribution: Worldwide in tropical and some warm-temperate areas.

Type locality: St Croix, Virgin Islands (Silva et al. 1996).

Acanthophora spicifera, somewhat overgrown by a filamentous epiphyte (Madagascar).

Acanthophora spicifera, detail (Madagascar).

Order Ceramiales

Family Rhodomelaceae

Aiolocolax pulchellus M.A.Pocock 1956: 22-31, figs. 3, 4, pls. 2-4

Plants minute, parasitic, comprising a vegetative filamentous part within thallus of host (Polysiphonia scopulorum) and colourless reproductive portions protruding beyond the surface of the host. Vegetative filaments monosiphonous, creeping between central and pericentral cells of host. Reproductive structures ovate, up to 200 µm tall, borne on single stalk cell, perpendicular to creeping filaments, comprising central axis and more than one periaxial cell per segment. In sporangial plants the periaxial cells bearing a globose polysporangium adaxially, with single cover cell on periphery; polysporangia up to 50 µm in diameter, dividing into ca 64 spores. In male reproductive bodies entire surface becoming spermatogenous tissue. Carposporophytes immersed in female fruiting bodies.

Collections, ecology and regional distribution

A parasite of Polysiphonia scopulorum, recorded from Blaauwberg on the west coast to Cape Vidal in northen KwaZulu-Natal (15-56).

World distribution: also found in Portugal, Spain, the Canary Islands and Namibia (Guiry & Guiry November 2010).

Type locality: Muizenberg, False Bay, Cape Province, South Africa (Silva et al. 1996).

Ailocolax pulchellus, early stage of polysporangium development: apical cell of fertile axis emerging from P. scopulorum axis.

Ailocolax pulchellus, developing polysporangium (stained slide).

Ailocolax pulchellus, later stage of developing polysporangium (stained slide).

Ailocolax pulchellus, maturing polysporangium (stained slide).

Ailocolax pulchellus, mature antheridia (stained slide).

Ailocolax pulchellus. 1. Microscopic habit of fertile male plant. 2. Emergent part of sporophyte, with polysporangia. Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Rhodomelaceae

Aphanocladia ecorticata Stegenga, R.J.Anderson & Bolton 2004: 167-170, figs 1-5

Plants small, filamentous, uncorticated. Main axes prostrate and probably of indefinite growth, attached by rhizoids cut off from ventral pericentral cells and with two opposite lateral rows of pinnate branchlets. Main axes up to 60 µm in diameter, segments up to 1.5 times longer than broad; branchlets ca. 35-50 µm in diameter, segments about as long as broad, and up to about 1.5 mm long but to 2.5 mm long when bearing tetrasporangia. Segments with 4 pericentral cells; branch initials arranged in a quarter spiral (either left- or right-handed) in successive segments. Trichoblasts absent. Tetrasporiferous segments with 5 pericentral cells; tetrasporangia developing in spiral series in ultimate branchlets, one per segment, globose and to ca 60 µm diameter, tetrahedrally divided, each with two long and one short cover cell. Other reproductive structures not seen.

Collections, ecology and regional distribution

Known from a single collection off Leven Point, near Stilbaai (26), from 5-6 m depth. Epiphytic on crustose corallines.

World distribution: South African endemic (and the only record of Aphanocladia from the Indian Ocean).

Type locality: near Leven Point, Western Cape Province, South Africa (Stegenga et al. 2004).

Note: The first (and only other) entity in this genus reported from South Africa (from west of Cape Agulhas) is Aphanocladia cf skottsbergii (Stegenga et al. 1997). However, that entity is larger, slightly corticated, and has a somewhat different branching pattern (Stegenga et al. 2004).

Aphanocladia ecorticata, dorsal view (stained slide).

Aphanocladia ecorticata, side view (stained slide).

Aphanocladia ecorticata, branch apex (stained slide).

Aphanocladia ecorticata, attachment disc (stained slide).

Aphanocladia ecorticata, tetrasporangia (stained slide).

Aphanocladia ecorticata, detail of tetrasporangia (stained slide).

Order Ceramiales

Family Rhodomelaceae

Bostrychia Montagne

Plants filamentous; main axes polysiphonous, with or without secondary cortication, pericentral cells divided transversely ; branching alternate, often regular, ultimate branches mono-or polysiphonous; vegetative trichoblasts absent. Tetrasporangia in stichidia in position of ultimate branchlets. Spermatangial heads cone-shaped, also as ultimate branchlets. Cystocarps borne on ultimate branchlets, globose to ovate. Sexual structures rare in most species.

The genus Bostrychia contains about 17 species worldwide (Guiry & Guiry, 2010), mainly from tropical and warm-temperate seas. Species are generally found at the edges of the marine environment, for example in estuaries and mangroves and in the upper eulittoral zone or supralittoral splash zone, for example in shaded overhangs, where they often form dark, fluffy turfs.

Seven species have been recorded from the South African south coast, but we have not collected all of them, and for some there is little or questionable material available for examination. Lambert et al (1987) provide detailed information on the distribution and morphology of most South African estuarine species.

Key to species

1 a. Branching regular, alternate, pinnate, thallus neatly feather-like

B. tenella

1 b. Branching sparse to profuse, irregular or regular, thallus not feather-like

2

2 a. Main axis up to 600 µm in diameter

B. harveyi

2 b. Main axes less than 400 µm in diameter

3

3 a. Thallus with (usually) 8 pericentral cells, 4-5 tier cells per axial cell; habitat rocky shores

B. intricata

3 b. Thallus with <8 pericentral cells, either 2 or 3 tier cells per axial cell; habitat estuaries, salt marshes or mangroves

4

4 a. Pericentral cells divided into 3 tier cells per axial cell

B. tangatensis

4 b. Pericentral cells divided into 2 tier cells per axial cell

5

5 a. Main axes ca. 350 µm in diameter

B. radicans

5 b. Main axes ca. 120 µm in diameter

6

6 a. Thalli upright or repent, branches alternate, at intervals of 3-5 segments

B. moritziana

6 b. Thalli of branched prostrate axes bearing upright laterals at irregular intervals, laterals simple or branched in 1-2 orders

B. simpliciuscula

Order Ceramiales

Family Rhodomelaceae

Bostrychia harveyi Montagne 1852: 317

Plants blackish-brown, forming creeping clumps up to a few cm in diameter, attached to stalks of estuarine higher plants. Apices strongly incurved; axes polysiphonous and corticated throughout, segments with 5-7 pericentral cells and well-developed cortication in up to 5 (-7) concentric layers, with the number of vertical tiers of cortical cells approximately doubling in each layer towards the periphery. Main axes about 600 µm in diameter. Branching alternate, laterals arising about every third segment, several times re-branched, complanate.

Tetrasporangial stichidia terminal on ultimate branchlets, conical or spindle-shaped, ca 1500 x 250 µm. Tetrasporangia 1-4 per segment, ca. 100 µm in diameter, other pericentral cells remaining sterile. Tetrasporiferous pericentral cells with three groups of cover cells: a small central and two larger lateral groups. Sexual structures not seen.

Collections, ecology and regional distribution

Recorded from Langebaan Lagoon on the west coast, and on the south coast from several estuaries between Knysna and Mntafufu in Transkei (13, 29-47) (as B. scorpioides – see note below). This is the largest of South African Bostrychia species, found on higher plants in the upper part of the littoral zone in some estuaries and mangroves.

World distribution: Chile, New Zealand, Tasmania and Victoria, Australia (Guiry & Guiry, 2010).

Type locality: Corral, Valdivia Province, Chile (Silva et al. 1996).

Note: Some authors, including Seagrief (1984), Lambert et al. (1987) and Stegenga et al. (1997), followed Post (1936) in referring this entity in South Africa to B. scorpioides. However, we follow Silva et al. (1996) in applying the name B. harveyi to this Southern Hemisphere entity, for reasons of both morphology (King & Puttock 1989) and molecular phylogeny (Zuccarello & West 2006).

Bostrychia harveyi, fresh material, Knysna Estuary (under dissecting microscope).

Bostrychia harveyi, apices of fresh material, Knysna Estuary (under compound microscope).

Bostrychia harveyi, cross section showing axial and seven pericentral cells surrounded by cortication.

Bostrychia harveyi. 1. Thallus apex, showing incurved tips. 2. Cross section of main axis. 3. Longitudinal section of young branch. 4. Tetrasporangial segments, immature. Reproduced from Stegenga et al. (1997), where it is cited as B. scorpioides.

Order Ceramiales

Family Rhodomelaceae

Bostrychia intricata (Bory de Saint-Vincent) Montagne 1852: 317

Plants blackish, forming dense woolly cover or tufts on rocks and in crevices at high tide level. Tufts 0.5 – 2 cm tall, with prostrate and upright axes. Polysiphonous throughout, segments usually with eight pericentral cells that divide transversely into 4 (-5) tiers of square or hexagonal cells with thick cell walls, further cortication absent; filaments up to 150 µm in diameter; young branch apices incurved. Branching in erect axes alternate, often every second segment, laterals usually not branching further.

Tetrasporangial stichidia rather incurved, terminal on lateral branchlets, attenuated cone-shaped, ca. 500 µm long, 150 µm wide. Stichidial segments with five pericentral cells, usually three bearing tetrasporangia and two remaining sterile and dividing as in vegetative axes. Fertile pericentrals cutting off tetrtasporangium and three uniseriate groups of cover cells: one central 2-3 celled group and two lateral 4-6 celled groups. Tetrasporangia to 60 µm diameter. Sexual reproduction not seen.

Collections, ecology and regional distribution

Recorded from Kommetjie on the west coast along the entire south coast to the Port Edward area of KwaZulu-Natal (24-47). Common on shaded faces and in crevices on rocky shores at high tide and in the splash zone.

World distribution: Fairly widely collected from various parts of the world, but on the African continent only recorded from South Africa (Guiry & Guiry 2010).

Type locality: Falkland Islands (Silva et al. 1996).

Bostrychia intricata, De Hoop.

Bostrychia intricata, curved tetrasporangial stichidia.

Bostrychia intricata, cells of fresh material.

Bostrychia intricata, cell detail.

Bostrychia intricata, young tetrasporangial stichidium.

Bostrychia intricata. 1. Habit, tetrasporangial plant. 2. Thallus apex. 3. Detail, showing central cells and divided pericentral cells. 4. Tetrasporangial stichidium (central filament black). Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Rhodomelaceae

Bostrychia moritziana (Sonder ex Kützing) J.Agardh 1863: 862

Plants reddish-brown, forming woolly tufts on the stems of salt-march plants, secondarily attached by rhizoids that develop from the apices of laterals, thalli rather fine and hair-like. Main axis polysiphonous, segments with 4-5 pericentral cells that divide transversely into two tiers; further cortication absent. Mature filaments ca 120 µm in diameter. Branching alternate, at intervals of 3-5 segments, laterals similarly re-branching, ultimate branchlets monosiphonous for many segments. Tetrasporangial stichidia borne on ends of polysiphonous branches, attenuated cone-shaped, up to 800 µm long and 150 µm wide. Tetrasporangial segments with four pericentrals, each becoming fertile and each cutting off a tetrasporangium and two 2-celled groups of cover cells. Sexual reproduction not seen.

Collections, ecology and regional distribution

Recorded in Langebaan Lagoon on the west coast (13) (Stegenga et al 1997). On the south coast recorded from Knysna Lagoon and by Lambert et al. (1987) from a number of estuaries from Nahoon (East London) to Kosi Bay in northern KwaZulu-Natal (30-58). Found in salt marshes attached to higher plants and any reasonably firm substrata.

World distribution: Found virtually worldwide in tropical and some warm temperate localities (Guiry & Guiry 2010).

Syntype localities: Antilles, West Indies; French Guiana (Silva et al. 1996); Venezuela, St Lucia and French Guiana and lectotype from Cumana, Venezuela (Womersley 2003).

Bostrychia moritziana, fresh material under dissecting microscope, Knysna Estuary.

Bostrychia moritziana, tetrasporangial stichidium.

Bostrychia moritziana. 1. Habit, tetrasporangial plant. 2. Thallus apex. 3. Detail, showing central cells and divided pericentral cells. 4. Tetrasporangial stichidium (central filament black). Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Rhodomelaceae

Bostrychia radicans (Montagne) Montagne 1842: 661

We were not able to examine material of this species. Jaasund (1976) describes this species as follows.

“Plants moss-like, forming 1-2 cm thick mats. Horizontal axes procumbent, attached to the solid substrate by disk-like haptera developing on ordinary branches. Erect branches about 100 µm thick, little branched, curved and becoming narrower upwards. Thallus is polysiphonous and not corticated like the other two species [B. tenella and B. binderi, now both regarded as B. tenella]. Tetrasporangia develop in stichidia, flat expansions on ordinary branches. They are about 200 µm broad. Growing in mangrove swamps on pneumatophores …” Lambert et al. (1987) note that their specimens are “About 1 cm tall, each pericentral with two pier cells per axial cell. Main axes and branches regular, polysiphonous, uncorticated”.

Collections ecology and regional distribution

Found on mangrove bark and pneumatophores from Kei Mouth to northern Kwazulu-Natal (43-58) (Lambert et al. 1987).

World distribution: Widespread throughout tropical regions (Guiry & Guiry 2010).

Type locality: French Guiana (Silva et al. 1996).

Bostrychia radicans, (re-drawn from Jaasund 1976, Fig. 257)

Order Ceramiales

Family Rhodomelaceae

Bostrychia simpliciuscula Harvey ex J.Agardh 1863: 854-855

Plants forming dense turfs to about 1 cm tall, brownish-red; branched prostrate axes bearing upright laterals at irregular intervals, simple or branched for 1-2 orders. Attachment by peripherohaptera (rhizoidal haptera arising in clusters from pericentral cells) originating near origins of upright branches. Apices straight or slightly curved. Pericentral cells (4-?) 5, dividing into 2 tiers, entirely ecorticate; polysiphonous or sometimes with apices of determinate laterals monosiphonous for up to 15 cells, arising at intervals of 2- 4 axial cells. Indeterminate axes 70- 120 µm in diameter, monosiphonous apices about 40 µm in diameter.

Tetrasporangial stichidia subapical or intercalary, 140-200 µm in diameter, 500-1500 µm long with 4 pericentral cells and tetrasporangia per whorl; tetrasporangia 40-60 µm in diameter, with 3 cover cells.

Collections, ecology and regional distribution

Our only record (BOL 143201) is from Mtakatye Estuary, Hluleka (45) as B. tenuis f. simpliciuscula (Bolton & Stegenga 1987), where it was epiphytic on mangroves.

World distribution: Recorded fairly widely from the tropical Pacific, and also from Ghana, Nigeria, and Eritrea (Guiry & Guiry 2010).

Type locality: Tonga (Silva et al. 1996).

Note: While our material generally fits the description of B. simpliciusculus, it is slightly smaller in vegetative dimensions, and has very few monosiphonous laterals. However, Zuccarello & West (2006) do not consider the presence or absence of monosiphonous laterals useful for distinguishing species in this subfamily (Bostrychioideae). This South African entity needs molecular studies.

Bostrychia simpliciuscula, re-hydrated material under dissecting microscope (BOL 143201).

Bostrychia simpliciuscula, vegetative axis, re-hydrated material (BOL 143201).

Bostrychia simpliciuscula, junction of prostrate and upright axes, showing peripherohaptera, re-hydrated material (BOL 143201).

Bostrychia simpliciuscula, tip of indeterminate lateral showing polysiphony immediately behind axial cell.

Bostrychia simpliciuscula, tetrasporangial stichidium, re-hydrated material (BOL 143201).

Bostrychia simpliciuscula, tetrasporangial stichidium in subapical/intercalary position.

Order Ceramiales

Family Rhodomelaceae

Bostrychia tangatensis Post 1939: 152-156

We have not seen specimens of this species: the following description is derived from that of Lambert et al. (1987).

“Plants forming fine, furry, maroon mat a few mm tall. Holdfasts developing at intervals along horizontal axes where one to several vertical axes arise, imparting dorsiventral appearance. Vertical axes unbranched, about 100 µm in diameter; pericentral cells with 3 tier cells per axial cell. Thalli completely uncorticated”.

Collections, ecology and regional distribution

Forming a “fine maroon fur on submerged Avicennia marina pneumatophores” and found in a number of mangroves from Kobonqaba (just north of the Kei River) to St Lucia in Kwazulu-Natal (43-58) (Lambert et al. 1987).

World distribution: Also recorded from Mozambique, Tanzania and Japan (Guiry & Guiry 2010).

Type locality: Kisosora, Tanga region, Tanzania (Silva et al. 1996).

Illustrations – none available. See Lambert et al. 1987 (Fig. 3a-c).

Order Ceramiales

Family Rhodomelaceae

Bostrychia tenella (Lamouroux) J. Agardh 1863: 869-871

Plants dark purple to brown, repent, forming mats of neatly feather-like thalli on the substratum; attached by rhizoids arising from bifurcations on the underside of prostrate axes; axes terete, up to 500 µm in diameter; alternately branched from each third to fourth axial cell, up to 3-4 orders of branches; ultimate and penultimate branches usually monosiphonous, other axes polysiphonous, composed of an axial filament surrounded by 5-7 pericentral cells, main axes with cortex 2-3 cells thick; transverse division of pericentral leaving 2 tiers per axial cell. Tetrasporangia in stichidia on ultimate branchlets, in whorls of 4 with 2(-3) cover cells, 30-70 µm in diameter, tetrahedrally divided. Sexual reproductive structures not seen. (See also De Clerck et al. 2005).

Collections, ecology and regional distribution

Recorded from Kei Mouth area to northern KwaZulu-Natal (43-58). Found in the upper eulittoral zone and splash zone of rocky shores, particularly on shaded rocks and in crevices, often with B. radicans.

World distribution: Widespread in tropical seas worldwide, including east and west Africa (Guiry & Guiry 2010).

Type locality: St Croix, Virgin Islands.

Bostrychia tenella, re-hydrated material (BOL 143203, Mtakatye Estuary, Hluleka) showing typical feather-like appearance.

Bostrychia tenella, re-hydrated material (BOL 143203, Mtakatye Estuary, Hluleka) bearing tetrasporangial stichidia.

Bostrychia tenella, re-hydrated material (BOL 143203, Mtakatye Estuary, Hluleka) showing branching detail.

Bostrychia tenella, re-hydrated material (BOL 143203, Mtakatye Estuary, Hluleka) detail of tetrasporangia.

Order Ceramiales

Family Rhodomelaceae

Chondria C. Agardh

Thallus branched, cylindrical to flattened, variable in size. Branching radial sometimes becoming secondarily distichous, branches usually narrowing at both ends, apices either pointed or sunken in a terminal pit. Holdfast a basal crust or prostrate stoloniferous branches. Structure polysiphonous, with a distinct central and 5 distinct pericentral cells. Cortication is by division of the pericentrals, producing a cortex with an inner layer of large pseudoparenchymatous cells and an outer layer (epidermis) of small, pigmented cells. Trichoblasts arranged spirally, usually highly branched.

Chondria species are found in most regions of the world, from the subantarctic to the tropics: 85 species and sub-specific taxa are currently recognised (MD Guiry in Guiry & Guiry 2016).

Although several species are recorded from the South African south coast, several more are present, and a molecular/morphological study of our species is overdue. Small Chondria species are common in algal turfs on the south coast, but we do not know how many species may be present: thorough collections and descriptions are required. Here we describe only one of these, a distinctive, larger entity, as Chondria sp. Indet.

Key to species

1a. Apices of axes with terminal pits, often containing tufts of trichoblasts

2

1b. Apices of axes pointed, without terminal pits but sometimes bearing trichoblasts

3

2a. Plants to 10 cm tall; axes stiffish, with spots/areas of green to turquoise iridescence; branches sparse, irregular

Chondria
sp. Indet.

2b. Plants to 10 cm tall; axes soft, without iridescence; branches fairly profuse

C. dasyphylla

3a. Axes stiffish, uprights to ca. 2 cm tall; main axis to 1 mm diameter; with radially-arranged branches up to 5 mm long: apices acute

C. armata

3b. Axes stiffish to lax, uprights to 20 (-30) cm tall; main axis to 3 mm diameter; branches several to 10 cm long

C. capensis

Order Ceramiales

Family Rhodomelaceae

Chondria armata (Kützing) Okamura 1907: 69, pl. XVI: figs 9-19

Plants pale pink, usually forming dense cushions of erect axes 1-2 cm high; prostrate axes irregularly branched, erect axes radially branched, terete, ca. 1 mm diameter basally, narrowing distally; ultimate branchlets 2-4 mm long and ca 400 µm in diameter; apices acute, with prominent apical cell and no apical depression; trichoblasts detaching easily but present in distal thallus. Structure of axial filament surrounded by 5 pericentral cells that remain visible throughout; inner cortex (medulla?) of isodiametric cells decreasing in size towards the surface of the thallus, outer cortical cells ca 20 µm in diameter. Tetrasporangia developing in ultimate branchlets, about 100 µm in diameter, tetrahedrally divided. Sexual structures not observed.

Collections, ecology and regional distribution

A mainly tropical species that extends down the KwaZulu-Natal coast as far as Bird Island in Algoa Bay (Anderson & Stegenga 1989). Usually forming extensive cushions in the lower eulittoral zone, but sometimes present as solitary plants.

World distribution: Widespread in the Indian Ocean and western Pacific (Guiry & Guiry 2016).

Type locality: New Caledonia (Silva et al. 1996).

Chondria armata, typical pink turf.

Chondria armata, single upright showing pine-tree like shape.

Order Ceramiales

Family Rhodomelaceae

Chondria capensis (Harvey) Askenasy 1888: 48

Plants dark purplish-green to blackish, up to 30 cm tall, stiff erect axes arising from small stoloniferous base; branches irregular, narrowing at both ends. Terminal branchlets spindle-shaped, often numerous and crowded, bearing apical tufts of trichoblasts, apical cell not sunken. Main axis cylindrical, to 3mm wide, in cross section with distinct central cell and five pericentrals surrounded by a cortex many cells thick; in longitudinal section central and pericentral cells long and cylindrical, cortical cells becoming progressively shorter towards surface of thallus.

Tetrasporangia ovate, ca. 150 x 100 um, immersed in terminal branchlets, developing laterally on radially elongated pericentral cells, usually four per segment. Antheridial stands disc-shaped, developing from first and second laterals of a trichoblast; up to 400 µm in diameter with sterile margin. Cystocarps globose, ca. 1 mm in diameter, clustered at apex of branchlets.

Collections, ecology and regional distribution

Common on the west coast in the sublittoral fringe of exposed localities, but extending to Tsitsikamma (1-32) (see note below).

World distribution: Also recorded from Namibia, Angola, Madagascar and Amsterdam and St Paul Islands (MD Guiry in Guiry & Guiry 2016).)

Type locality: Table Bay, Western Cape (Silva et al 1996).

Note: Some south coast specimens in BOL that are identified as C. capensis are very much smaller than the typical west coast entity in all dimensions, and may be of another species.

Chondria capensis. 1. Habit. 2. Tetrasporiferous ramuli. 3. Ramulus of male plant, showing antheridial discs. Reproduced from Stegenga et al. 1977 (west coast material).

Chondria capensis. Plate 214, Fig 5 from Stegenga et al. (1997), showing cross section of axis.

Order Ceramiales

Family Rhodomelaceae

Chondria dasyphylla (Woodward) C.Agardh 1817: XVIII

Plants purplish-red to yellowish, soft, comprising solitary or clumped terete erect axes arising from a discoid holdfast. Main axes 0.5-1.5 mm in diameter, lateral branches thinner, arising in spiral pattern at irregular intervals, decreasing in length distally and imparting rather pyramidal shape to thallus; branch apices obtuse, with terminal pit sometimes with trichoblasts. Young main axes with distinctive diamond pattern visible through cortex; structure of axial cell, 5 distinctive pericentral cells, 3-5 layers of subcortical cells interwoven with rhizoidal filaments in older axes and single layer of cortical cells. Branches club-shaped and constricted basally when young, ultimate branchlets up to about 0.5 mm diameter.

Tetrasporangia 150-200 µm in diameter, in subcortical layer of last two branch orders. Cystocarps on short stalks, globose becoming rather flask-shaped, up to about 1 mm long. Spermatia borne in plates grouped near apices of young branches.

Collections, ecology and regional distribution

Although this species has been recorded from Tsitsikamma through to northern Kwazulu-Natal, including from Hluleka (Bolton & Stegenga 1987), the only south coast specimen that appears to fit the description is one from the Kowie Lagoon, Port Alfred (see note). The distribution is therefore uncertain.

World distribution: virtually worldwide in temperate and tropical seas (MD Guiry in Guiry & Guiry 2016).

Type locality: Norfolk, England (Silva et al 1996).

Notes: 1. for a detailed descriptions of this species in the UK, see Maggs & Hommersand (1993). 2. The illustration of this species from Hluleka (Bolton & Stegenga 1987, Fig 3d) does not appear to show the “conspicuous diamond pattern visible through the cortex of young axes” that Maggs & Hommersand (1993) report as characteristic of this species.

Chondria dasyphylla, Kowie Lagoon, Port Alfred.

Order Ceramiales

Family Rhodomelaceae

Chondria sp. Indet.

Thalli erect, a few to 10 cm tall, main axes 500 - 1200 µm in diameter, sparsely branched, dark red to purplish, usually with striking patches or spots of green or turquoise iridescence. Holdfast of repent stoloniferous branchlets; erect axes single or several; axes and branches tapering basally and distally, branching polystichous, irregular, rather sparse. Apices with pits, usually containing trichoblasts. In cross-section, axial cells, five periaxial cells and another 1-2 layers of large cells clearly visible sections, surrounded by 2-3 (-4) layers of cells becoming smaller towards the outside. Cell dimensions rather variable, depending on individual specimens and part of thallus sectioned Axial cell 65-90 µm diameter; periaxial cells 100-200 µm diameter, usually ovate in cross section (elongated radially); next layer of cells the same size as periaxials or slightly larger; cell sizes then decreasing radially through 3-5 layers, outer (epidermal) layer of radially elongated cells 15-25 µm long and 10-15 µm wide. Tetrasporangia borne in short, clavate or spindle-shaped terminal branchlets that are often in clusters.

Collections, ecology and regional distribution

Distinctive on account of the iridescent spots, this species is recorded from De Hoop to Mkambathi (24-47). It is not uncommon in the lower eulittoral zone, where it often grows in taller turfs and in among other seaweeds such as Hypnea spicifera.

Note: This species looks very similar to C. scintillans Feldmann from southern Europe and the Mediterranean, but the whole genus requires molecular study.

Chondria sp indet. Morgan Bay specimens, in situ, showing habit and iridescent turquoise spots (specimen D 2598).

 Chondria sp indet. Morgan Bay specimens - note iridescent turquoise spots (specimen D 2598).

 Chondria sp indet. De Hoop specimens, in situ, showing patches of turquoise iridescence.

 Chondria sp indet. Morgan Bay specimens, magnified to show iridescent turquoise spots and frond shape (specimen D 2598).

 Chondria sp indet. Morgan Bay specimen showing apical pit with emergent trichoblasts (specimen D 2598).

 Chondria sp indet. Morgan Bay specimen – cross section showing 5 periaxial cells, etc. (specimen D 2598).

 Chondria sp indet. East London specimen – cross section showing anatomy (stained slide EC 355).

 Chondria sp indet. East London specimen – cross section showing outer cortex and detail of anatomy (stained slide EC 355).

 Chondria sp indet. Morgan Bay specimens, pressed mounts (specimen D 2598).

Order Ceramiales

Family Rhodomelaceae

Colacopsis velutina (M.T.Martin & M.A.Pocock) R.E.Norris 1988: 233

Plants parasitic on Rhodomelopsis africana, with an endophytic portion comprising monosiphonous filaments penetrating the host tissue and an external portion comprising a pustule of pseudoparenchymatous tissue with radiating polysiphonous filaments bearing reproductive structures. Tetrasporiferous filaments up to 500 µm long, with short monosiphonous base and polysiphonous segments bearing tetrasporangia; tetrasporangial segments with 5 pericentral cells of which 3 remain sterile and 2 become fertile, each producing a tetrasporangium and 2 cover cells. Sporangia tetrahedrally divided, about 20 µm in diameter, approximately opposite in segment, generally in vertical rows but sometimes decussate. Cystocarps globose with a narrow lateral ostiole and multilayered pericarp.

Collections, ecology and regional distribution

Recorded from Brandfontein, just west of Agulhas, to East London (22-41). Known only as a parasite of Rhodomelopsis africana.

World distribution: Probably a South African endemic: the record of this species from Kerguelen Island is questioned by Norris (1988).

Type locality: Three Sisters, Eastern Cape (Norris 1988).

Note: see Martin and Pocock (1953) for) detailed illustrations and descriptions of this species (as Melanocolax velutina). These authors distinguish the pustules of Colacopsis from the white “galls” that can be found on Rhodomelopsis: The pustules are reported to be softer than the galls, to have a velvety surface, and usually to be lower down on the host plants.

Colacopsis velutina on Rhodomelopsis (Bol 148948 rehydrated specimen).

Colacopsis velutina on Rhodomelopsis - detail (Bol 148948 rehydrated specimen).

Colacopsis velutina. 1. Cross section of tetrasporophyte on the host Rhodomelopsis africana. 2. Tetrasporiferous filaments (note monosiphonous base). Reproduced from Stegenga et al. (1997).

Ceramiales

Family Rhodomelaceae

Dasyclonium J.Agardh, 1894: 80

Thalli small, prostrate, polysiphonous, dorsiventral, ecorticate, usually epiphytic. Holdfasts rhizoidal, developing from ventral surface of certain segments. Prostrate axes with latero-dorsal determinate branches arising in alternating pattern from every second segment. Tetrasporangia and sexual reproductive structures formed on distal second-order laterals. Ten species of Dasyclonium are recognised (Guiry & Guiry 2010), among which two have been recorded on the South African south coast. The phylogeny of the genus is discussed by Scagel (1962).

Key to species

1a. Ultimate branchlets not fused laterally, determinate laterals comb-like

D. incisum

1b. Lower-most two branchlets of ultimate series partly fused laterally, determinate laterals palmate

D. palmatifidum

Ceramiales

Family Rhodomelaceae

Dasyclonium incisum (J.Agardh) Kylin 1956: 534, fig. 427B-D, fig. 430B, C

Plants red to reddish-brown, 0.5- 5 cm long, epiphytic, basal to mid portion attached to host by rhizoids, distal portion free, complanate, branched indeterminate axes bearing comb-like (pectinate) determinate laterals 0.5 – 1.5 mm long, in alternating series, from every second segment, polysiphonous throughout. Structure of 6 pericentral cells in indeterminate axes and 3 in determinate axes; apices often slightly curved, dome-shaped apical cell 15-20 µm in diameter. Trichoblasts absent. Cells uninucleate, rhodoplasts discoid and chain-like in larger cells. Rhizoids arising from adjacent axial pericentral cells in pairs. Tetrasporangial branches arising above each determinate lateral, tetrasporangia arranged in straight series, 120-180 µm in diameter, each with 3 cover cells that may divide further. Gametophytes dioecious; cystocarps sessile, ovoid, 350-600 µm in diameter, ostiolate, pericarp two cells thick, ecorticate; spermatangial organs triradiate, borne near base of lower branches of determinate laterals.

Collections, ecology and regional distribution

Recorded from northern Transkei to Park Rynie area of KwaZulu-Natal (47-50). Epiphytic on various larger algae, from the lower eulittoral to at least 20 m.

World distribution: also recorded from India, Australia and New Zealand (Guiry & Guiry 2010).

Type locality: Australia (Agardh 1841).

Dasyclonium incisum on segment of an articulated coralline.

Dasyclonium incisum - detail of structure.

Ceramiales

Family Rhodomelaceae

Dasyclonium palmatifidum (Grunow) Scagel 1962: 1029-1030, figs. 7, 8, 29, 30

Plants procumbent, red, up to 3 cm long, epiphytic, composed of polysiphonous axes attached over most of their ventral surface by paired rhizoidal pads from two adjacent pericentral cells; distichous determinate laterals arising every second segment. Axes cylindrical, about 170 µm in diameter, comprising central axial filament and 6 pericentral cells; determinate laterals polysiphonous, each with 4-5 side branches on adaxial side, side branches formed from every second segment; lowermost lateral similarly branched but laterals partly fused. Tetrasporangia in a straight series of up to 12 segments in distal parts of indeterminate axes, one per segment, cover cells 3 initially but sometimes dividing again.

Collections, ecology and regional distribution

Recorded from the Tsitsikamma area to Shelly Beach, southern KwaZulu-Natal (31-50). Epiphytic on various algae from the lower eulittoral down to at least 40 m depth.

World distribution: South African endemic.

Type locality: Algoa Bay (Silva et al. 1996).

Dasyclonium palmitifidum, epiphytic on Zonaria.

Dasyclonium palmitifidum, stained slide.

Dasyclonium palmitifidum, detail, stained slide.

Dasyclonium palmitifidum, juvenile.

Dasyclonium palmitifidum, cell details with rhizoidal holdfast pad.

Dasyclonium palmitifidum, tetrasporangium.

Order Ceramiales

Family Rhodomelaceae

Dictyomenia stephensonii Papenfuss 1947: 4-5, pl. 1: fig. 4; pl. 2: figs. 12, 13 ('Dictymenia')

Plants dark maroon-red, erect, up to 25 cm tall, with spirally twisted, dentate axes; attachment by stoloniferous axes; flattened complanate uprights borne on short (-1.5 cm) stipe, 2-5 mm wide, with tooth-like determinate laterals up to about 3 mm long, apices of uprights twisted but not inrolled. Structure comprising central axial filament and 6 pericentral cells, lateral pericentral cells dividing to form wings of axes, cortication of a single layer of small cells; midrib distinct in lower parts of thallus; axial filaments visible when axes held to the light; determinate laterals arising from every fourth segment, alternately branched, angled towards apices. Reproductive structures not seen.

Collections, ecology and regional distribution

Recorded from the Mbashe River Mouth (Dwesa/Cwebe, Transkei) to Cape Vidal area. (44-56). Found in the sublittoral fringe and in pools, often in shaded locations.

World distribution: South African endemic.

Type locality: Port Shepstone, Kwazulu-Natal (Silva et al. 1996).

Dictyomenia stephensoniae, habit (pressed specimen).

Dictyomenia stephensoniae, young pressed specimen.

Dictyomenia stephensoniae, detail of frond showing midrib, determinate laterals (teeth)

Dictyomenia stephensoniae, cross section through midrib of mature frond (re-hydrated pressed specimen).

Dictyomenia stephensoniae, xs showing cortical cells and outer medulla (re-hydrated pressed specimen).

Order Ceramiales

Family Rhodomelaceae

Hawaiia sp 1

Plants forming a dense blackish turf up to 5 mm high. Axes with (10-) 12-14 pericentral cells per segment throughout the thallus, without further cortication. Prostrate axes with straight (horizontal) apex, giving off ascending filaments at intervals of about five segments. Rhizoids cut off from pericentral cells at the ventral side of prostrate filaments , up to three or four rhizoids per segment, unicellular, with a terminal digitate hapteron. Prostrate axes up to 160 µm in diameter, the segments about half as long as broad. Erect filaments several times pseudodichotomously branched at intervals of 5-12 segments, origin of laterals exogenous or at the base of a trichoblast; basal segment of lateral not distinguishable from corresponding segment of main axes, being similar in height and number of pericentral cells, the two branches confluent for the proximal one and a half segments. Erect axes at their base up to 140 µm in diameter , gradually tapering towards the apex, the apical cells being ca. 12.5 – 15 µm in diameter; segments 0.3-0.5 times as long as broad. Trichoblasts spirally arranged, but not present on every segment, simple, usually not over 7 cells long, soon deciduous.

Tetrasporangia in more or less tortuous series in subterminal sections of the erect filaments; sporangia globose, up to 50 (-60) µm in diameter, tetrahedrally divided, with two long cover cells. Male stichidia spindle-shaped to cylindrical, at maturity ca. 130 x 35 µm, with a single-celled pedicel and a sterile apical cell, but male trichoblasts with no other sterile parts. Cystocarps ellipsoid to almost globose, ca. 250 µm in diameter, with a narrow ostiole.

Collections, ecology and distribution

So far collected between Robberg (Plettenberg Bay) and the Tsitsikamma Coastal National Park (31-32) but probably much more widespread. This species forms low turfs on animal substrata (molluscs, ascidians) in wave-exposed locations, from the lower eulittoral to shallow sublittoral zone. Our specimens were growing together with several other species including Anotrichium tenue, Centroceras clavulatum and Herposiphonia tenella.

Note: The genus Hawaiia was maintained by Abbott (1999) on the basis of three characters that separate it from Polysiphonia. All three of these characters are present in our species, namely: 1. Possession of unbranched trichoblasts, 2. The basal segment of laterals being similar to the corresponding segment of the bearing axis both in length and number of pericentral cells, and 3. Spermatangial stichidia developing from the entire trichoblast primordium, thus bearing no sterile parts, other than a one-celled pedicel and a single apical cell. However, our species differs from the type and only other species, H. trichia, by its somewhat larger size (erect axes up to only 2 mm tall in H. trichia), the higher number of pericentral cells (8-11 in H. trichia) and the thicker axes (erect axes to 60-70 µm in H. trichia).

Hawaiia sp I, fresh material, Nature’s Valley (Scale bar = 1mm).

Hawaiia sp I, fresh material, Nature’s Valley, showing junction of erect and prostrate axes, and attachment rhizoids.

Hawaiia sp., microscopic habit of female thallus.

Hawaiia sp., detail of prostrate system.

Hawaiia sp., apex of erect axis, showing frequent association of laterals with trichoblasts.

Hawaiia sp., cystocarp (left) and tetrasporic axis (right).

Hawaiia sp., detail of tetrasporangia.

Order Ceramiales

Family Rhodomelaceae

Herposiphonia Nägeli

Thalli differentiated into long indeterminate axes and shorter, usually unbranched determinate laterals. Main axes usually prostrate. Branching pattern regular, usually with each segment bearing a lateral in repeating series of three determinate and one indeterminate branch (or branch primordium). Determinate laterals rarely with trichoblasts. All axes uncorticated, number of pericentral cells in the genus 6-18, range within each species narrower. Attachment rhizoids arising from ventral pericentral cells, usually developing terminal haptera or pads. Reproductive structures developing on determinate branchlets. Tetrasporangia usually one per segment, in straight series. Cystocarps lateral on determinate branchlets.

Species discrimination is based on number of pericentral cells, size and shape of branchlets and position of reproductive structures. See Wynne (1984) for an earlier account of the genus in South Africa. About 45 species of Herposiphonia are currently accepted taxonomically (Guiry & Guiry 2013), of which we record 5 species and one forma from the south coast. Another species, H. insidiosa, is widespread but seems indistinguishable from our H. falcata (see note under the latter species).

Key to species

1a. Cells in suprabasal segment of determinate laterals much longer than other cells

H. clavata

1b. Cells in suprabasal segment of determinate laterals similar length to other cells

2

2a. Determinate laterals dorsal, very sparse, arising usually only from every fourth segment of prostrate axes

H. secunda

2b. Determinate laterals arising from (almost) every segment of prostrate axes in series of three to each indeterminate lateral (or branch primordium)

3

3a. Determinate laterals relatively long (up to 50 segments), often rather straight, not congested, arranged in single dorsal row

H. secunda
f. tenella

3b. Determinate laterals a maximum of 30 segments long, arranged either in dorsal row or arising alternately and dorso-laterally from indeterminate laterals

4

4a. Determinate laterals compressed, in single dorsal row, with maximum of 27 segments per lateral

H. prorepens

4b. Determinate laterals cylindrical, in one or roughly two lateral rows

5

5a. Determinate laterals with segments 0.3 times as long as broad, stout, blunt, with a maximum of 18 segments per lateral, tetrasporangia 2 per segment

H. didymosporangia

5b. Determinate laterals with segments 0.5-0.8 times as long as broad, maximum of 30 segments per lateral, tetrasporangia 1 per segment

H. falcata

Order Ceramiales

Family Rhodomelaceae

Herposiphonia clavata M.J. Wynne 1984: 168-169, figs 1-5

Indeterminate axes prostrate, up to 4 (-10) mm long, attached by unicellular rhizoids with attachment pads; up to two or three rhizoids per segment: branched in regular series of three determinate and one indeterminate branches. Main axes 80-115 µm diameter, 8-9 pericentral cells per segment; determinate branches erect, simple, broadly clavate, incurved towards apex of plant, 250-600 µm tall and comprising 10-14 segments, segments in middle of determinate branches 90-130 µm wide with 10-12 pericentral cells; trichoblasts absent except in procarpic branchlets. Tetrasporangia 80-100 µm in diameter, in rectilinear series in determinate laterals, borne in segments distal to the elongated suprabasal cell. Cystocarps 340-400 µm in diameter, globose to slightly urceolate. Antheridial stands ca. 200 µm long x 50 µm wide, arising abaxially near ends of determinate laterals, cylindrical, slightly curved and clavate.

Collections, ecology and regional distribution

Collected from Arniston to northern KwaZulu-Natal (23-58). Generally epiphytic on larger algae, especially articulated corallines (more especially various Amphiroa species), in the intertidal and shallow subtidal zones.

World distribution: also recorded from New Zealand (Guiry & Guiry 2013)

Type locality: Umdloti, KwaZulu-Natal, South Africa (Silva et al. 1996).

Note: For further illustrations of reproductive structures in Eastern Cape (Hluleka) material see Bolton and Stegenga (1987).

Herposiphonia clavata, apex of thallus showing branching (stained slide).

Herposiphonia clavata, note elongated cells in suprabasal segments (stained slide).

Herposiphonia clavata, tetrasporangial branches (stained slide).

Herposiphonia clavata, tetrasporangia in single row (stained slide).

Herposiphonia clavata, antheridial stands (stained slide).

Herposiphonia clavata, detail of antheridial stands (stained slide).

Order Ceramiales

Family Rhodomelaceae

Herposiphonia didymosporangia Stegenga and Kemperman 1987: 133

Plants prostrate. Indeterminate axes attached by unicellular rhizoids that may become digitate, up to five rhizoids per segment. Determinate laterals stout, blunt, cylindrical, up to 200 µm wide and 1500 µm long, comprising about 18 segments, each about one third as long as broad. Six pericentral cells in basal segment, increasing up to 18 in mid region of axes. Tetrasporangia 70-80 µm in diameter, two per segment, in two rectilinear series in all except the basal and most distal segments of determinate laterals. Sexual reproduction unknown.

Collections, ecology and regional distribution

Collected from St James (False Bay), Brandfontein (just west of Cape Agulhas), De Hoop and Tsitsikamma (17-32). Epilithic and on articulated corallines in the lower eulittoral.

World distribution: also recorded from Luderitz, Namibia (Stegenga et al. 1997).

Type locality: St James, False Bay, South Africa (Silva et al. 1996).

Note: see also Stegenga et al. (1997).

Herposiphonia didymosporangia, structure of thallus (stained slide, isotype material, BOL).

Herposiphonia didymosporangia, apex of male thallus with antheridial stands (stained slide, isotype material, BOL).

Herposiphonia didymosporangia, detail of part of determinate lateral (stained slide, isotype material, BOL).

Herposiphonia didymosporangia, detail of tetrasporangia (stained slide, isotype material, BOL).

Herposiphonia didymosporangia. 1. Detail of main axis with determinate and indeterminate laterals. 2. Apex of tetrasporiferous branchlet (after Stegenga and Kemperman 1987). Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Rhodomelaceae

Herposiphonia falcata (Kützing) De Toni 1903: 1060

Plants brown to blackish, prostrate, apical tips curved upwards. Indeterminate axes attached by digitate haptera arising from pericentral cells. Main axes with segments about as long as broad, with 10-12 pericentral cells. Haptera one or two per segment. Determinate branches cylindrical, incurved, apices fairly blunt, number of pericentrals often 12 (10-14) except in basal segment (5-6 pericentrals), to 1200 (-2000) µm long, 80-120 µm in diameter, comprising (15-) 18-25 (-30) segments, segments 0.5-0.8 times as long as broad. Tetrasporangia ca. 70 µm diameter, in 3rd-14th segments of determinate branchlets, in rectilinear series of up to 12 per branchlet. Antheridial stands cylindroconical, ca. 240x50 µm, adaxial on segments 3-9 of branchlets. Cystocarps urn-shaped, 500-600 µm diameter, one per branchlet, on segments 4 or 5 but in some specimens only after segment 15. We include records of H. insidiosa here (see note below).

Collections, ecology and regional distribution

Recorded from Brandfontein (just west of Cape Agulhas) to Mzamba (22-48). A very common species, usually epiphytic on articulated corallines and sometimes on other larger algae.

World distribution: South African endemic.

Type locality: “Cape of Good Hope” (Silva et al. 1996).

Note: Stegenga et al. (1997) point out that this species is very similar to the more widespread H. insidiosa (Grev. ex. J.Agardh) Falkenberg (1901) that was recorded from Kwazulu-Natal by Wynne (1984) and from Hluleka by Bolton and Stegenga (1987). Our slide material of the Hluleka specimens cannot be distinguished from our material of H. falcata, suggesting that on our coast, these entities need re-examination.

Herposiphonia falcata, fresh material, Nature’s Valley.

Herposiphonia falcata, vegetative structure (stained slide).

Herposiphonia falcata, determinate lateral s arising dorso-laterally (stained slide).

Herposiphonia falcata, densely branched thallus (stained slide).

Herposiphonia falcata. 1. Thallus apex. 2. Detail of prostrate axis, showing origin of rhizoids, determinate and indeterminate laterals. Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Rhodomelaceae

Herposiphonia prorepens (Harvey) F. Schmitz 1895: 158

Plants bright to dark red, prostrate. Indeterminate axes attached by digitate haptera. Haptera not more than one per segment, often at regular intervals of two or three segments. Segments of main axis about as long as broad, with 12 pericentral cells. Indeterminate laterals arising laterally from main axis, alternate, often stunted. Determinate laterals in single dorsal row, apices acute, compressed, 300-2000 µm high and 100-160 µm wide, consisting of 15-27 segments each 0.3-0.5 times as long as broad; number of pericentral cells 10(-12), basal segment with four pericentral cells.

Tetrasporangia ca. 180x120 µm, one per segment in rectilinear series of rarely more than five, developing in segments 5-13 of branchlets that at maturity are closely packed. Antheridial stands on segments 6-11, abaxial. Cystocarps 700-800 x 500-600 µm, ovate to urn-shaped, one per determinate lateral, on segments 6-10.

Collections, ecology and regional distribution

Recorded from Cape Hangklip (120 km west of Cape Agulhas) to the Durban area of Kwazulu-Natal (19-51). Usually epiphytic on species of Amphiroa, especially A. ephedraea, from the eulittoral and shallow subtidal zones.

World distribution:A lso recorded from Chagos Archipelago, India, Indonesia (Silva et al. 1996).

Type locality: Algoa Bay, South Africa (Silva et al. 1996).

Notes: Wynne (1984) points out that Harvey’s (1862) record of H. prorepens from Australia does not refer to this species. Also, Stegenga et al. (1997) consider this species to include H. akidoglossa, described from Kwazulu-Natal by Norris (1992).

Herposiphonia prorepens, on Amphiroa sp, fresh material, Nature’s Valley.

Herposiphonia prorepens, fresh material, Nature’s Valley.

Herposiphonia prorepens, showing dorsal row of determinate laterals (stained slide).

Herposiphonia prorepens, apex of thallus (stained slide).

Herposiphonia prorepens, tetrasporangia (stained slide).

Herposiphonia prorepens, cystocarp borne laterally on determinate branchlet (stained slide).

Herposiphonia prorepens. 1. Microscopic habit. 2. Detail of prostrate axis and determinate laterals. 3. Haptera beneath prostrate axis. 4. Tetrasporiferous branchlet. Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Rhodomelaceae

Herposiphonia secunda (C.Agardh) Ambronn 1880: 197-198, pl. IV: figs 8, 11, 12

Plants prostrate with erect axes up to 1.5 mm tall; determinate laterals arising in dorsal row from (usually) every fourth segment of indeterminate axes; apices of prostrate axes curved upwards. Prostrate axes attached by rhizoids arising from ventral pericentral cells, rhizoids developing hapteral attachment pads. Usually one rhizoid per segment. Indeterminate branches alternate. Determinate laterals cylindrical, 50-70 (-80) µm in diameter, up to 30 segments high and straight in mature parts of plant; 8-10 pericentral cells per segment, segments 1.0-1.3 times as long as broad, usually slightly narrower than prostrate indeterminate laterals; young laterals curled forward near tips; trichoblasts sometimes present, subapical. Indeterminate laterals 50-100 µm in diameter, young apices curled backward. Reproductive structures not seen.

Collections, ecology and regional distribution

Recorded from Walker Point near Goukamma to Hluleka (29-45). Epiphytic on larger articulated corallines.

World distribution: various tropical and warm temperate localities - see note.

Type locality: Mediterranean Sea (Silva et al. 1996).

Note: There is some confusion concerning this taxon, which is variously treated as H. secunda (C. Agardh) Ambronn or H. secunda f. secunda. Variations in descriptions of this taxon from different parts of the world indicate morphological differences and the need for a thorough re-examination. Meanwhile, we are able to distinguish it from the more common and widespread H. secunda f tenella because the latter has (almost always) one determinate lateral per prostrate segment in a series of three determinate to one indeterminate laterals.

Herposiphonia secunda, showing rather sparse determinate laterals (stained slide).

Herposiphonia secunda, structure (stained slide).

Herposiphonia secunda, showing sparse determinate laterals every fourth segment of prostrate axis.

Order Ceramiales

Family Rhodomelaceae

Herposiphonia secunda f. tenella (C.Agardh) M.J.Wynne 1984: 173, 175, figs. 11, 12

Plants prostrate with erect axes up to about 5 mm tall; branches produced from almost all segments of indeterminate axes. Prostrate axes attached by up to three rhizoids per segment; rhizoids may become digitate; apices of main axes curved upwards, often overtopped by apices of young determinate laterals that curl forward. Indeterminate branches alternate; determinate branches in dorsal row, arising from (almost) every segment in a series of three determinate/ one indeterminate lateral. Determinate branches comprising usually about 30 (but up to 50) segments, incurved when young, becoming straight when mature, usually narrower than prostrate branches, often with a few subapical or apical trichoblasts. Segments cylindrical, with (8-) 10-12 pericentral cells, up to 35-70 (-80) µm in diameter, 1-3 times as long as broad, basal cell with four pericentral cells. Tetrasporangia one per segment, in rectilinear series. Antheridial stands in adaxial series or arranged radially and subapically. Cystocarps one per branchlet, rarely seen, somewhat urn-shaped, ca. 350 (high) X 300 µm (wide), usually on 4th to 6th segment.

Collections ecology and regional distribution

Recorded from Cape Agulhas to Park Rynie in Kwazulu-Natal (22-50). A common component of short algal turfs on the south coast, also found in “limpet gardens” and growing on various larger algae and sessile animals such as Pyura and mussels.

World distribution: Widespread in warm temperate and tropical seas.

Note: Jaasund (1976) records 12-16 pericentral cells in H. secunda f. tenella from Tanzania.

Herposiphonia secunda forma tenella showing general structure (stained slide).

Herposiphonia secunda forma tenella showing general structure (stained slide).

Herposiphonia secunda forma tenella, trichoblasts on determinate laterals (stained slide).

Herposiphonia secunda forma tenella, antheridial stands (stained slide).

Herposiphonia secunda forma tenella. 1. Habit. 2. Apex of prostrate filament. 3. Mature erect filaments (note well developed trichoblasts). Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Rhodomelaceae

Janczewskia meridionalis M.T.Martin & M.A.Pocock 1953: 62, figs. 3 a, 3b

Plants parasitic, forming lobed, translucent whitish pustules 1-3 mm in diameter on the hosts (Laurencia spp). Rhodomelacean structure only apparent in apices: apical cells in depressions, cutting off row of central cells which give rise to trichoblasts, elongate radiating pericentral cells and a cortex. Attachment to host by penetrating rhizoidal filaments, developing pit connections with host cells. Reproductive structures sunken in conceptacles. Tetrasporangia ovate, ca.70x40 µm, tetrahedrally divided, lining conceptacles; surface of conceptacle also with free branched filaments. Antheridia in plumose clusters lining interior of conceptacles. Cystocarps globose, forming lobes on thallus surface, ostiolate.

Collections, ecology and regional distribution

Recorded from Brandfontein (just west of Cape Agulhas) to the Cape St Lucia area in northern KwaZulu-Natal (22-55). Parasitic on Laurencia flexuosa and other species of Laurencia.

World distribution: South African endemic.

Type locality: Riet River, Eastern Cape Province, South Africa (Martin & Pocock 1953).

Janczewskia meridionalis on Laurencia sp.

Jancczewskia meridionalis cross section through conceptacles (stained slide)

Jancczewskia meridionalis 1. Habit (white) on Laurencia sp. 2. Thallus apex in longitudinal section. Reproduced from Stegenga et al. (1997).

Jancczewskia meridionalis 1. Section of thallus with tetrasporangial conceptacles. 2. Detail of Fig. 1. Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Rhodomelaceae

Laurencia Lamouroux

Plants erect, a few to 40 cm tall; holdfasts discoid, rhizoidal or encrusting; thallus branching profuse to sparse, polystichous to regularly bilateral; branches compressed to terete. Axes polysiphonous but forming several layers of pseudoparenchymatous tissue; four pericentral cells present; axial and periaxial (pericentral) cells clearly visible in some species; branch apices with terminal sunken pit, trichoblasts usually present. Outer cortical cells without secondary pit connections, containing one to many intracellular colourless inclusions (corps en cerise) these visible only in fresh material, the number per cell characteristic for each species. Medullary cell walls with lenticular thickening in some species. Reproductive structures usually on terminal branchlets, sometimes on main axes. Tetrasporangial initials arising from pericentral cells, tetrasporangia sub-cortical, arrangement sometimes species-specific. Cystocarps protruberant, ostiolate.

The genus Laurencia is one of six genera in the Laurencia complex, the other five being Palisada, Chondrophycus, Laurenciella, Osmundea, and Yuzurua ((Nam et al. 1994, Garbary & Harper 1998, Nam 2007, Martin-Lescanne et al. 2010 and Cassano et al. 2012). Laurencia sensu stricto is the largest of these genera, with 145 species currently recognised (MD Guiry in Guiry & Guiry 2017).

Francis (2014), reported that “the species count for the South African Laurencia complex is now fourteen Laurencia species, three Palisada species, and one species each in the genera Chondrophycus and Laurenciella”. See Francis et al. (2017) for further descriptions of new South African Laurencia species: only those that occur on the south coast are included here.

Note: Although Laurencia obtusa has been recorded from the south coast (e.g. Stegenga et al. 1997), the study of Francis et al. (2017) shows that it does not occur here, and specimens that were given this name are probably either L. pumila ssp. dehoopiensis or Laurencia cf. corymbosa.

Key to south coast species

1a. Axes and laterals slightly to strongly compressed

2

1b. Axes and laterals terete

4

2a. Axes strongly compressed, oppositely branched

L. complanata

2b. Axes slightly compressed, alternately to irregularly branched

3

3a. Axes irregularly alternately branched, outer cortical cells with 1-3 corps en cerise

L. flexuosa

3b. Axes alternately branched, outer cortical cells with 5-6 corps en cerise

L. alfredensis

4a. Plants entirely olive-green, caespitose

L. griseaviolacea

4b. Plants entirely a shade of red to purple or with some red, pink or purple on the thallus

5

5a. Plants entirely a shade of red to purple (essentially one colour)

6

5b. Plants bi-coloured

9

6a. Primary laterals spirally arranged, higher order laterals whorled or alternate

L. glomerata

6b. Branching polystichous, alternate to opposite or subverticillate in higher order laterals

7

7a. Plants epiphytic , subtidal, ultimate branches wart-like

L. pumila ssp dehoopiensis

7b. Plants epilithic

8

8a. Plants to 15 cm tall, axes to 1.5 mm diameter, fertile terminal branchlets corymbose

L. cf corymbosa

8b. Plants to 4 cm tall, axes to 0.5 mm diameter, laterals mostly adaxially arranged

L. digitata

9a. Main axes up to 1.5 mm in diameter, plants olive becoming purple distally, sparsely branched

L. pumila

 9b. Main axes up to 1 mm in diameter

9

10a. Plants with pyramidal outline

L. natalensis

10b Plants tufted to caespitose, no pyramidal outline

L. multiclavata

Order Ceramiales

Family Rhodomelaceae

Laurencia alfredensis Francis, Bolton, Mattio et R.J. Anderson in Francis et al. 2017: 810-811, Fig. 3

Plants dark red to purplish-red, epilithic, up to 35 cm tall; axes compressed, 1-3 mm wide and 0.5-1 mm thick. Holdfast stoloniferous, thalli complanate, main axes percurrent, branching alternate in up to 4 orders. Branches basally constricted; ultimate branchlets wider than long, with truncated apices. In cross-section axial (central) and periaxial cells clearly visible. Periaxial cells to more than 100 um wide; cells becoming smaller outwards; outer cortical cells up to 60 um wide. Outermost cortical cells each containing 4-6 small corps en cerise. Cystocarps up to 500 um in diameter, on penultimate branchlets. Tetrasporophytes and male gametophytes not seen.

Collections, ecology and regional distribution

So far recorded from Grootbank (Tsitikamma area) to Double Mouth (31-43) but probably more widespread because previous collections would have been identified as L. flexuosa (see note). Found in lower eulittoral and shallow sublittoral zones.

Word distribution: apparently a South African endemic.

Type locality: Port Alfred, Eastern Cape Province, South Africa (Francis et al. 2017).

Note: L. alfredensis is morphologically very similar to L. flexuosa, and only DNA analysis led to them being recognised as separate species, after which some morphological differences were found (Francis et al. 2017). Under a compound microscope the easiest way to distinguish fresh material of the two species is by the number of corps en cerise per outer cortical cell: 4-6 in L. alfredensis vs 1-3 in L. flexuosa.

Laurencia alfredensis, Double Mouth.

Laurencia alfredensis, frond detail.

Laurencia alfredensis, alternate branching, with cystocarps near apices.

Laurencia alfredensis, surface view showing 4-6 small corps en cerise in each outer cortical cell.

Order Ceramiales

Family Rhodomelaceae

Laurencia complanata (Suhr) Kützing 1849: 857

Plants red to dark red, epilithic, complanate, up to about 20 cm tall. Holdfast discoidal, bearing several pyramidal axes, axes 3-4 mm wide, pinnately branched in up to 4 orders. Branches closely spaced, equal lengths on each side of axes. Terminal branches short (0.5-1 mm long), truncated. In cross section central (axial) cell and four (indistinct) pericentral cells. Medullary cells becoming smaller outwards, often with thickened cell walls (lenticular thickening); single layer of cortical cells, 40-50 um high. Tetrasporangia borne in terminal branchlets, 130-150 um in diameter, division tetrahedral. Sexual structures not seen.

Collections, ecology and regional distribution

Recorded from Hluleka eastwards to northern KwaZulu-Natal (45-58). Found in rock pools and the shallow subtidal zone.

Word distribution: Also reported from Mozambique (De Clerck et al. 2005).

Type locality: Durban, KwaZulu-Natal, South Africa (De Clerck et al. 2005).

Note: A DNA study of South African Laurencia supported this as a valid species (Francis et al. 2017).

Laurencia complanata, frond detail.

Laurencia complanata, cross section showing cortex and some of medulla.

Laurencia complanata, cross section showing secondary pit connections between outer medullary cells.

Order Ceramiales

Family Rhodomelaceae

Laurencia cf corymbosa J.Agardh 1852: 747

Plants purplish-red to dark purple when fresh, fleshy, up to 15 cm tall. Discoid holdfast bearing several (usually) percurrent axes; axes terete, up to 1.5 mm in diameter, irregularly alternately branched in 2-4 orders. First order branches arising irregularly, becoming shorter distally; second-and higher-order branches sub-oppositely branched, shorter; ultimate branches subverticillate, with truncated apices, corymbose when fertile. Branches without basal constrictions. In cross-section axial and periaxial cells not distinguishable. Medullary cells and inner cortical cells larger than outer cortical cells and with intercellular spaces; outer cortical cells dome-shaped, about 15-45 x 10-35 µm, each with one corps en cerise. Reproductive structures not seen.

Collections, ecology and regional distribution

Recorded from De Hoop to Double Mouth (24-43). Epilithic in the lower eulittoral and shallow subtidal zones.

Word distribution: Also reported from Seychelles, South China Sea, Vietnam and Fiji (references in Guiry & Guiry 2017).

Type locality: “Cape of Good Hope”, South Africa (Agardh 1852).

Note: A DNA study of South African Laurencia (Francis et al. 2017) identified a clade (based on 8 specimens) that was provisionally identified as Laurencia cf corymbosa. One of the most distinguishing characteristics is the dome-shaped epidermal cells, each containing one corps en cerise. However, the characteristic corymbose shape of the secondary branches is only evident in fertile specimens.

Laurencia cf corymbosa. The pale dots near some apices are spent tetrasporangia, and the dark patches are an endo-or epiphyte.

Laurencia cf corymbosa, with corymbose fertile branchlet. The pale spots are where tetrasporangia were released.

Laurencia cf corymbosa, cross section of outer edge of thallus.

Laurencia cf corymbosa, cross section of outer edge of thallus: detail of inner and outer cortical cells, the outer cells each containing one corps en cerise.

Laurencia cf corymbosa, surface view showing detail of outer cortical cells, each containing one corps en cerise.

Order Ceramiales

Family Rhodomelaceae

Laurencia digitata Francis, Bolton, Mattio et R.J. Anderson 2017 Francis et al. 2017: 812, Fig 5

Plants reddish-brown, epilithic, caespitose, up to 4 cm tall. Holdfast rhizoidal, axes terete, to 0.5 mm in diameter, some axes percurrent; branching in 2-3 orders, ultimate branchlets truncated, with apical pits. Branching usually alternate, but sometimes sub-opposite or subverticillate. In cross section axial (central) and pericentral cells visible, medullary an cortical cells becoming smaller outwards; outer cortical cells to 8-25 um wide, each containing a single corps en cerise. Reproductive structures not seen.

Collections, ecology and regional distribution

Recorded from De Hoop and a few localities on the south coast, with one specimen from Sodwana in northern KwaZulu-Natal (24-57). Apparently a mid- to low-intertidal species.

Word distribution: A South African endemic.

Type locality: Koppie Allen, De Hoop, Western Cape Province, South Africa (Francis et al. 2017).

Note: L. digitata is superficially similar to L. pumila, but aside from genetic differences, the former species is reddish-brown and branched throughout the thallus (Francis et al. 2017).

Laurencia digitata.

Laurencia digitata, branching pattern.

Laurencia digitata, surface view of outer cortical cells, each with one corps en cerise.

Order Ceramiales

Family Rhodomelaceae

Laurencia flexuosa (Suhr) Kützing 1849: 856

Plants bright red to brownish-red or purplish-red, one to several erect axes arising from a common holdfast, up to 40 cm tall. Plants complanate, branching irregularly alternate, main axis flexuous; older plants with several orders of branches, not crowded except when fertile. Axes compressed, 2-3 mm wide and about half as thick. In cross section central and pericentral cells not distinguishable. Medulla of isodiametric, rather thin-walled cells; no special cell-wall thickenings present; outer cortical cells wider than deep, in surface view about isodiametric, with secondary pit-connections in the longitudinal direction. Outermost cotical cells with 1-3 corps en cerise. Reproductive plants with clusters of crowded terminal branchlets.

Collections, ecology and regional distribution

Recorded from False Bay eastwards to Mabibi in northern KwaZulu-Natal (45-57). On wave-exposed shores, from the lower eulittoral zone to shallow sublittoral.

Word distribution: Also reported from Mozambique (De Clerck et al. 2005).

Type locality: “Cape of Good Hope”, South Africa (De Clerck et al. 2005).

Note: Easily confused with L. alfredensis, but the latter species has 5-6 corps en cerise in the outer cortical cells and is more regularly branched. Prior to the DNA study of South African Laurencia (Francis et al. 2017), which described L. alfredensis, entities of both species would have been identified as L. flexuosa.

Laurencia flexuosa, Tsitsikamma.

Laurencia flexuosa, Tsitsikamma; shorter, denser plants.

Laurencia flexuosa, detail. White spots near apices show where tetrasporangia were shed.

Laurencia flexuosa, surface view of outer cortical cells, each with 1-3 corps en cerise.

Order Ceramiales

Family Rhodomelaceae

Laurencia glomerata (Kützing) Kützing 1849: 857

Plants dark red, bushy, often pyramidal in outline, up to 40 cm tall, several erect axes arising from a single discoid holdfast. Axes terete, 1-3 mm in diameter, branched in up to 3 orders. First order branching spiral to polystichous, second and higher order branches shorter and branching distichous, sub-opposite or verticillate. Laterals arising at long interval: basal constrictions absent from branches. Ultimate branches ca 0.5 mm wide and 1 mm long, apices truncated. In cross section central and pericentral cells not distinguishable; medulla of isodiametric , rather thick-walled cells, cell-wall thickenings sometimes present, Outer cortical cells deeper than wide, especially in older parts of thallus; in surface view at first isodiametric, becoming longitudinally elongate with secondary pit-connections, sometimes interspersed with a network of small-celled filaments and containing 1 (rarely 2) corps en cerise per cell.

Collections, ecology and regional distribution

Recorded from Port Nolloth on the west coast to Island Rock in KwaZulu-Natal (2-57). Epilithic in the lower eulittoral and shallow subtidal zones, in exposed and sheltered areas. Stegenga et al. (1997) point out that in very sheltered bays, this species exhibits a very lax form.

Word distribution: Also reported from India, Pakistan, Indonesia and temperate South America (references in Guiry & Guiry 2017).

Type locality: Cape Peninsula, South Africa (Kützing 1847).

Note: A DNA study of South African Laurencia (Francis et al. 2017) confirms that phylogenetically, L. glomerata emerges as a distinct species.

Laurencia glomerata, False Bay, Western Cape.

Laurencia glomerata.

Laurencia glomerata, detail of tetrasporic branch.

Laurencia glomerata, surface view of outer cortical cells showing single corps en cerise per cell.

Laurencia glomerata. 1. Habit. 2. Detail of branchlets (releasing spermatia). 3. Cross section. 4. Young male trichoblasts. 5. Detail of spermatangial head (note swollen terminal cells). Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Rhodomelaceae

Laurencia griseaviolacea M.J. Wynne 2017: 1

Plants dark olive green to violet, epilithic, densely caespitose, forming cushions up to 4 cm tall. Erect axes with few polystichously arrange primary laterals: secondary laterals very short and terminal branchlets wart-like and very dense. Axes terete, up to 1.5 mm in diameter. In cross section central cell distinguishable, but pericentral cells not different from other medullary cells. Medullary cells moderately thick-walled, special cell-wall thickenings absent. Outer cortical cells about as deep as, or deeper than broad; in surface view isodiametric to longitudinally elongated, with secondary pit-connections; each containing a single corps en cerise. Reproductive structures not seen.

Collections, ecology and regional distribution

Recorded from False Bay (Western Cape) to East London (17-41). Found on wave-exposed rock in the mid to lower eulittoral zones.

World distribution: A South African endemic.

Type locality: Clovelly, Cape Peninsula, Western Cape (Stegenga et al. 1997, as L. peninsularis).

Note: This species was originally described as L. peninsularis Stegenga, Bolton & Anderson (Stegenga et al. 1997), but the name was invalid as it had been used by Taylor (1945) for another Laurencia species. The name Laurencia stegengae was proposed by Francis et al. (2017), but this is also invalid as the name L. griseoviolacea had already been given to it a few months earlier by Wynne (2017). Finally, the name was corrected to L. griseaviolacea by MD Guiry in Guiry & Guiry (2017).

Laurencia griseaviolacea.

Laurencia griseaviolacea, typical caespitose habit.

Laurencia s griseaviolacea, single branch showing short secondary laterals.

Laurencia griseaviolacea, surface view of cortical cells, each with one corps en cerise.

Laurencia griseaviolacea. 1. Apex of erect axis. 2. Cross section. Reproduced from Stegenga et al. (1997: as L. peninsularis).

Order Ceramiales

Family Rhodomelaceae

Laurencia multiclavata Francis, Bolton, Mattio et R.J. Anderson in Francis et al. 2017: 813-814, Fig. 6

Plants green with pale pink to purple apices, epilithic, caespitose, up to 8 cm tall. Holdfast stoloniferous, axes terete, 0.5-1.0 mm in diameter, some axes percurrent; branching polystichous (subopposite to subverticillate) in 2 (to rarely 3) orders; ultimate branchlets short and wart-like, half the width of main axes, apices truncated. In cross section axial (central) and pericentral cells clearly visible, medullary and cortical cells becoming smaller outwards; inner cortical cells with intercellular spaces, outer cortical cells each containing 2-4 (usually 3) corps en cerise. Reproductive structures not seen. This species may be confused with L. natalensis (see note).

Collections, ecology and regional distribution

Recorded from De Hoop to northern KwaZulu-Natal (24-57). Found on sand-influenced rock in the mid to lower eulittoral and in the shallow sublittoral zones.

Word distribution: A South African endemic.

Type locality: Koppie Allen, De Hoop, Western Cape Province, South Africa (Francis et al. 2017).

Note: Superficially, L. multiclavata can easily be mistaken for L. natalensis, but aside from genetic differences, the former species is polystichously rather than radially branched, has fewer order of branching, does not have a pyramidal outline and has more corps en cerise per cortical cell (there is only one per cortical cell in L. natalensis). (Francis et al. 2017).

Laurencia multiclavata.

Laurencia multiclavata. Cross section: note axial cell and pericentral cells.

Laurencia multiclavata. Surface view of outer cortical cells, each with 2-4 corps en cerise.

Laurencia multiclavata. Trichoblasts emerging from apical pits and with 2-4 corps en cerise per cell. .

Order Ceramiales

Family Rhodomelaceae

Laurencia natalensis Kylin 1938: 24, pl. 8: fig. 21

Plants green with orange to red apices, forming erect tufts up to 10 cm tall. Stoloniferous basal parts bearing several upright axes of 0.7-1.0 mm diameter; uprights radially branched in many (usually 3, but up to six) orders, branches shorter toward apices, imparting pyramidal outline to thallus. Ultimate branchlets cylindrical to clavate, fairly crowded in fertile thalli. In cross section of main axis central and pericentral cells easily distinguished; medullary cells moderately thick-walled, with ocassional special wall thickenings. Cortical cells 25-30 µm high, each containing 1 corps en cerise. Tetrasporangia borne in swollen terminal branchlets, tetrahedrally divided, 60-80 µm in diameter. Sexual structures not seen.

Collections, ecology and regional distribution

Recorded from Pearly Beach in the Western Cape to northern KwaZulu-Natal (21-58). Found on wave-exposed shores in the lower eulittoral and shallow sublittoral zones; often associated with sand cover.

Word distribution: Also reported from East Africa, Sri Lanka, Vietnam and Mauritius (Guiry & Guiry 2017).

Type locality: Isipingo, KwaZulu-Natal, South Africa (De Clerck et al. 2005).

Note: A DNA study of South African Laurencia supported this as a valid species (Francis et al. 2017), but described a morphologically similar new species (L. multiclavata) with which it can be confused. The main differences are in branching pattern: L. natalensis has narrow radial branching and a pyramid-shaped outline, whereas L. multiclavata has a generally wider, polystichous branching pattern, fewer branch orders and no pyramidal outline. Furthermore, where L. natalensis has one corps en cerise per outermost cortical cell,  L. multiclavata has 2-4.

Laurencia natalensis, Tsitsikamma.

Laurencia natalensis, showing radial branching and elongated pyramidal outline.

Laurencia natalensis, surface view of outer cortical cells, each with one corps en cerise.

Laurencia natalensis. 1. Thallus apex (tetrasporiferous). 2. Cross section. 3. Surface view of cortex. 4. Cross section of tetrasporiferous ramulus. Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Rhodomelaceae

Laurencia pumila (Grunow) Papenfuss 1943: 91-92

Plants green with purple apices, up to 2.5 cm tall, up to 2 orders of branches. Several axes arising from a rhizoidal holdfast; apices clavate; axes terete, 1-1.5 mm wide, unbranched when young; in mature thalli short ultimate branchlets 0.5-2.2 (-3) mm wide near the base, apices truncated apices. In cross-section axial and pericentral cells indistinguishable. Innermost cortical and medullary cells two to three times larger than outermost cortical cells. Innermost cortical cells round with visible intercellular spaces, lenticular cell wall thickenings absent. Outermost cortical cells with (usually) 1 corps en cerise per cell.

Collections, ecology and regional distribution

Recorded from Tsitsikamma to northern KwaZulu-Natal (32-58)(De Clerck et al. 2005). Epilithic in the mid-eulittoral zone, where it forms distinctive small tufts.

Word distribution: Also reported from Mozambique (De Clerck et al. 2005).

Type locality: Port Natal (Durban), South Africa (Silva et al. 1996).

Note: L. pumila differs from other South African Laurencia species in that the thallus is sparsely branched and has club-shaped apices. Francis et al. (2017) distinguish a subspecies, L. pumila ssp dehoopiensis, which is epiphytic and geographically widely separated from L. pumila.

Laurencia pumila, KwaZulu-Natal.

Order Ceramiales

Family Rhodomelaceae

Laurencia pumila var dehoopiensis Francis, Bolton, Mattio et R.J. Anderson in Francis et al. 2017: 814-815, Fig. 7

Thalli red, epiphytic, up to 14 cm tall, terete, main axes percurrent. Axes up to 1.5 mm in diameter, branching in 2-3 orders, polystichous, branching alternate to subverticillate, laterals shortening towards apices, becoming wart-like near tips; apical pits present. In cross-section axial (central) and periaxial cells visible, medullary cells to more than 100 um in diameter, cells becoming smaller outwards; outer cortical cells 17-30 um long, 18-25 um wide. Outermost cortical cells each containing a single corps en cerise. Reproductive structures not seen.

Collections, ecology and regional distribution

So far only recorded at Koppie Alleen, De Hoop. Subtidal, epiphytic on Phloiocaulon suhrii.

Word distribution: apparently a South African endemic.

Type locality: Koppie Allen, De Hoop, Western Cape Province, South Africa (Francis et al. 2017).

Laurencia pumila var. dehoopiensis.

Laurencia pumila var. dehoopiensis. Detail of sparse branching and club-shaped terminal branches.

Laurencia pumila var. dehoopiensis. Cross section; note visible axial and periaxial cells.

Order Ceramiales

Family Rhodomelaceae

Lophosiphonia Falkenberg in F.Schmitz & Falkenberg

Thalli polysiphonous, ecorticate, mostly prostrate, with dorsal erect branches. Prostrate axes bearing determinate erect branches that arise endogenously (from the axial cells) and irregularly. Erect branches unbranched or with sparse secondary branches, usually with trichoblasts; trichoblasts arising in secund or spiral series. Pericentral cells reported to be 4-18 in genus, but 4-19 in South African south coast species. Rhizoids ventral on prostrate axes, with lobed attachment pads. Reproductive structures borne on erect branches; tetrasporangia one per segment, arranged in spiral series; gametophytes dioecious, antheridial stands conical, replacing trichoblasts; cystocarps ovoid.

There is some taxonomic confusion regarding the distinction between this genus and Polysiphonia. Nine species of Lophosiphonia are currently recognised (Guiry & Guiry 2011), of which two are recorded from the south coast of South Africa.

Key to species

1a Pericentral cells four

L. capensis

1b Pericentral cells 10 – 19

L. reptabunda

Order Ceramiales

Family Rhodomelaceae

Lophosiphonia capensis (Kylin) R.E.Norris 1992: 68

Plants tiny, dark red, usually epiphytic or epizoic, comprising relatively long prostrate axes and short (up to 2 mm) erect branches; visible to the naked eye as fine red hairs . Prostrate filaments about 100 µm in diameter, with upward-curving apices, attached by haptera that arise from pericentral cells. Segments uncorticated, with four pericentral cells. Erect filaments up to about 70 µm in diameter, segments 0.5-1 times as long as broad. Erect axes arising endogenously from dorsal faces of prostrate axes at intervals of 2 or 3 segments; usually strongly incurved; unbranched or with a few laterals arising adaxially. Vegetative trichoblasts absent. Tetrasporangia in erect axes, one per segment, in rectilinear series, up to 70 µm in diameter, with two long and one short cover cells. Antheridial stands subapical on erect filaments, cylindrico-conical. Cystocarps usually on proximal segments of laterals, globose, up to 200 µm in diameter.

Collections, ecology and regional distribution

Recorded from St James (False Bay) to the Durban area (17-51). Common on the south coast on Pyura and various larger algae, especially corallines such as Amphiroa spp., from the lower eulittoral to shallow subtidal zones.

World distribution: South African endemic.

Type locality: False Bay, Cape Province, South Africa (Silva et al. 1996).

Note: This species was previously known as Falkenbergiella capensis Kylin. A somewhat different growth form (as Falkenbergiella capensis) was recorded at Hluleka (Transkei) by Bolton & Stegenga (1987, Fig. 3f). Plants had few erect branches and the determinate laterals (usually two per segment) were “appressed against the substrate”.

Lophosiphonia capensis tip (stained material, slide EC 440).

Lophosiphonia capensis, tetrasporophyte (stained slide).

Lophosiphonia capensis, detail of tetrasporangium (stained slide).

Lophosiphonia capensis, male thallus with sub-apical antheridia.

Lophosiphonia capensis, cystocarpic thallus (stained slide).

Lophosiphonia capensis, detail of cystocarps, with carpospores - some released (stained slide).

Lophosiphonia capensis. 1. Microscopic habit. 2. Detail of prostrate axis with young erect branch. 3. Cystocarps. Reproduced from Stegenga et al. 1997 (as Falkenbergiella capensis).

Order Ceramiales

Family Rhodomelaceae

Lophosiponia reptabunda (Suhr) Kylin 1956: 539

Plants forming turfs up to 2 mm tall, comprising intertwined prostrate axes and abundant erect axes, all with 10-19 pericentral cells. Prostrate axes with prominent apical cells and down-curving at tips, 70-150 µm in diameter, segments 0.8-1.0 times as long as broad; frequently irregularly branched, branching usually oppositely dorso-lateral. Rhizoids frequent, often arising in pairs on same segment, from mid- posterior regions of pericentral cells, with discoid or digitate attachment pads. Erect axes distally curved forward, usually up to 50 segments long before bearing secund branches or trichoblasts; 70-100 µm in diameter, segments 0.7 – 1.0 times as long as broad. Tetrasporangia ca 70 µm in diameter, in rectilinear or spiral series in erect branches that may branch in up to four orders, 2 cover cells per sporangium. Cystocarps abaxial, globose, 250-300 µm in diameter.

Collections, ecology and regional distribution

Recorded from just west of Stilbaai to the Durban area (25-51). A component of lower eulittoral and shallow sublittoral turfs.

World distribution: Widespread in warm temperate and tropical seas (Guiry & Guiry, 2011).

Type locality: Biarritz, Pyrénées-Atlantiques, France (Silva et al., 1996).

Lophosiphonia reptabunda, vegetative thallus.

Lophosiphonia reptabunda, vegetative thallus ca 2.5 mm tall (slide material).

Lophosiphonia reptabunda, prostrate axis with dorsal and ventral rhizoids.

Lophosiphonia reptabunda, detail of branch.

Lophosiphonia reptabunda, junction of prostrate axis and young branch, with ventral rhizoid.

Order Ceramiales

Family Rhodomelaceae

Microcolax africanus M.T.Martin & M.A.Pocock 1953: 56-58, fig. 5; pl. 12: figs a-c (as 'africana')

Parasitic on a species of Streblocladia, as small round pustules on the filaments of the host, comprising short branched axes radiating from the host tissue and attached by penetrating rhizoidal branches. Vegetative filaments with four pericentral cells, occasionally corticated basally. Free axes with short stalks and profuse distal branching. Tetrasporangia in cylindrical stichidia, usually developing from one row of pericentral cells and arranged in single row. For rurther details see Martin & Pocock (1953).

Collections, ecology and regional distribution

Recorded from the type locality (Cove Rock, East London)(41).

World distribution: South African endemic.

Type locality: Cove Rock, near East London, South Africa (Martin & Pocock (1953).

Microcolax africanus, tetrasporic stichidia. Re-drawn from Martin & Pocock (1953).

Microcolax africanus, germinating sporeling on Streblocladia tenuissima. Re-drawn from Martin & Pocock (1953) (as M. africanus).

Order Ceramiales

Family Rhodomelaceae

Onychocolax polysiphoniae M.A. Pocock 1956: 32-38, figs. 5a-l; 6a-p, pl. 5: figs A-J; pl. 6: figs A-F

Plants microscopic, parasitic on Polysiphonia incompta, often causing deformed growth of host. Filamentous, monosiphonous in vegetative parts, branched vegetative axes growing between axial and pericentral cells of host. Trichoblasts only present in female plants, in the form of short hairs at the apex of each branchlet, the apical cell of which bears one or two characteristically claw-like hairs. Fertile axes producing reproductive structures external to host on polysiphonous branches with four pericentral cells. Tetrasporangial axes simple, each segment dividing off four pericentral cells that develop into four rows of tetraspores; tetrasporangia often in stichidia, tetrahedrally divided, each with two cover cells. Male axes usually simple, stalked, forming single antheridial branch but sometimes bi-or polyfurcate.Young female axes with distinctive crab-like appearance, cystocarps one or two, each ca 160 x 220 µm, ostiolate.

Collections, ecology and regional distribution

Only recorded from Cannon Rock to Three Sisters (Pocock 1956) in the Eastern Cape (38-39), but probably more widespread. Only found as a parasite of Polysiphonia incompta.

World distribution: South African endemic.

Type locality: Port Alfred (The Kowie), beyond Salt Vlei, South Africa, parasitic on Polysiphonia incompta (Pocock 1956).

Onychocolax polysiphoniae, filaments of thallus growing between cells of Polysiphonia, with claw-like female reproductive parts emerging from host tissue (re-drawn from Pocock 1956).

Order Ceramiales

Family Rhodomelaceae

Ophidocladus simpliciusculus (P.L.Crouan & H.M.Crouan) Falkenberg in Schmitz & Falkenberg 1897: 461

Plants red, growing in turfy clumps or mats up to 20 (-30) mm high, comprising prostrate filaments with erect branches; polysiphonous, ecorticate. Prostrate axes attached by numerous haptera cut off from pericentral cells, apices down-curved. Erect axes arising endogenously from dorsal face of axial cells of prostrate filaments at short intervals, re-branching up to several orders. Segments of prostrate and erect filaments up to 200 µm in diameter, shorter than broad, with 16-20 (-24) pericentral cells. Erect filaments sparsely and irregularly branched, apices with two rows of alternating trichoblasts at intervals of two to several segments. Tetrasporangia two per segment, in two rectilinear series in distal parts of lateral branches; tetrasporiferous branches sometimes crowded, swollen and apparently with reduced number of pericentral cells in tetrasporiferous parts: tetrasporangia up to 80 µm in diameter, with two long cover cells. Antheridial stands trilobed, with monosiphonous sterile apices. Cystocarps globose to ovoid, up to 400 µm in diameter.

Collections, ecology and regional distribution

Recorded from Platboom, just west of Cape Point, to northern Kwazulu-Natal (17-58).

A component of sand-binding turfs in the lower eulittoral, giving the appearance of longish red fur. A possible record from Hondeklipbaai on the South African west coast is discussed by Stegenga et al. (1997).

World distribution: In southern Africa also recorded from Namibia (Rull Lluch 2002) and Mozambique (Silva et al. 1996), otherwise widely recorded from tropical and warm temperate oceans (Guiry & Guiry 2011).

Type locality: Finistère, France (Silva et al. 1996).

Note: Saenger (1971) discusses the occurrence of this species in southern Africa.

Ophidocladus simpliciusculus.

Ophidocladus simpliciusculus, tetrasporangia.

Ophidocladus simpliciusculus, detail of tetrasporangia.

Ophidocladus simpliciusculus, tetrasporangia in rectilinear series.

Ophidocladus simpliciusculus, dorsal branch and ventral rhizoids, fresh specimen, Nature’s Valley.

Ophidocladus simpliciusculus, trichoblasts, fresh specimen, Nature’s Valley.

Ophidocladus simpliciusculus, cell detail, fresh specimen, Nature’s Valley.

Ophidocladus simpliciusculus, male thallus: tri-lobed antheridial stands.

Ophidocladus simpliciusculus, 1. Habit, tetrasporangial plant. 2. Thallus apex. 3. Tetrasporangia. Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Rhodomelaceae

Osmundaria serrata (Suhr) R.E.Norris 1991: 23, 29, figs 34-42

Plants red to brownish-red or yellowish-red, erect, up to 40 cm high, stiff to cartilaginous, with spirally twisted ribbon-like branches bearing regularly-spaced small teeth along margins; holdfast conical, prominent, woody. Proximal axes cylindrical, woody; distal axes flattened, up to 5 mm wide, sometimes with faint midrib; indeterminate branching sparse, at intervals of 0.5 – 6.0 cm; branches regularly twisted, margins with regular alternate serrations (determinate laterals) about 1 mm apart and 1 mm long, often with serrulations at the tip; apices inrolled. Axes comprising central filament of axial cells, 5 pericentral cells and 2 pseudopericentral cells on the dorsal side; determinate laterals arising alternately on every second or third segment; thallus corticated with 2-3 layers of cells. Reproductive structures borne on adventitious branchlets, usually clustered distally on serrations but sometimes on midrib. Tetrasporangia in fusiform stichidia that are about 1 mm long, in two rows, about 90 µm in diameter. Male plants with ovoid antheridial stands in clusters on adventitious branchlets that are borne abaxially near tips of marginal teeth, ca 80 µm in diameter with monosiphonous stalk cells. Female plants with fertile branchlets clustered on abaxial sides of marginal teeth; branchlets with curved apices and rudimentary trichblasts,usually one cystocarp per branchlet, ovoid, ca 650 µm in diameter, small terminal ostiole.

Collections, ecology and regional distribution

Recorded from Port Alfred eastward to Mission Rocks in northern Kwazulu-Natal (39-54). Found from the lower eulittoral zone to at least 40 m depth.

Worldwide distribution: Also reported from the Maldives (Silva et al. 1996).

Type locality: Mtentu, east of Port St Johns, Eastern Cape, South Africa (Silva et al. 1996).

Note: Norris (1991) points out that this species can be distinguished from the superficially similar Dictyomenia stephensonii by the absence of inrolled branch tips in the latter. Osmundaria serrata was formerly known as Vidalia serrata (Suhr) J. Agardh. See Norris (1991) for details of this and other Osmundaria species. O. serrata is the only South African species in this genus with fertile branchlets borne on marginal teeth.

Osmundaria serrata.

Osmundaria serrata, showing characterisitic twisting and a branch (re-drawn from Norris 1991).

Osmundaria serrata, tetrasporangial stichidia (re-drawn from Norris 1991).

Order Ceramiales

Family Rhodomelaceae

Pachychaeta Kützing

Plants comprising prostrate and erect axes, cylindrical, polysiphonous, uncorticated. Prostrate axes either stoloniferous or rhizomatous, latter bearing specialized adventitious, polysiphonous branches for attachment, true rhizoids absent. Axes with 6-16 pericentral cells: number, shape and arrangement varying with species. Trichoblasts absent, lateral branches exogenous or adventitious. Erect axes arising irregularly from stoloniferous axes. Reproductive structures developing on reduced branchlets that are spirally arranged on erect axes. Cystocarps globose, one per branchlet, without ostiole. Tetrasporangia two per segment. Two species are currently recognized, both endemic to southern Africa.

Key to species

1a. Axes about 1 mm in diameter, cells hexagonal in surface view

P. brachyarthra

1b. Axes up to 250 µm in diameter, hexagonal cells not visible

P. cryptoclada

Order Ceramiales

Family Rhodomelaceae

Pachychaeta brachyarthra (Kützing) Trevisan 1875: 384, footnote

Plants pinkish-red to dark red, comprising prostrate axes bearing erect axes up to 20 cm long and about 1 mm in diameter, often forming loose, somewhat tangled stringy thalli. Axes cylindrical, uncorticated, radially organized, with 6-11 pericentral cells, irregularly and sparsely branched, with unbranched apices. Cells in surface view characteristically elongated hexagonal. Reproductive structures borne on bushy branchlets. Tetrasporangia two per segment, in spiral rows in stichidium-like structures cut off from ends of fertile branches, stichidia branched or unbranched. Antheridial stands compound with cylindrical lobes and sterile tips. Cystocarps globose, one per fertile branchlet, with small spines at tips.

Collections, ecology and regional distribution

Recorded from Cape Agulhas along the entire south coast through to northern Kwazulu-Natal (22-58).Found in the lower eulittoral and shallow sublittoral, often in slightly protected areas, forming tangled masses among other seaweeds on the substratum.

Worldwide distribution: South African endemic.

Type locality: "Cap" (probably Cape Agulhas, Cape Province, South Africa) (Silva et al. 1996).

Pachychaeta brachyarthra, entangled in a Plocamium sp., Struis Bay.

Pachychaeta brachyarthra, thallus tips.

Pachychaeta brachyarthra, showing elongated hexagonal cortical cells.

Pachychaeta brachyarthra, stichidium-like tetrasporangial branchlets.

Order Ceramiales

Family Rhodomelaceae

Pachychaeta cryptoclada Falkenberg 1901: 577-579, pl. 13: fig. 16

Plants dark red to blackish, comprising prostrate axes and erect axes up to 50 mm tall. Prostrate axes attached by haptera cut off from pericentral cells. Segments cylindrical, about 0.9-1.0 times as long as broad, with 10-16 pericentral cells, uncorticated. Axes up to 250 µm in diameter, branching apparently irregular and sparse, but spirally-arranged branch initials formed on each segment and remaining visible in older parts as groups of small cells. Laterals arising exogenously; no vegetative trichoblasts present. Reproductive structures in stichidium-like structures formed by repeated re-branching of laterals. Tetrasporangia two per segment, arranged decussately; up to 120 µm in diameter, with two long and one short cover cells. Antheridial stands short cylindrical. Cystocarps globose, without ostiole (we have not seen sexual reproductive structures in our material).

Collections, ecology and regional distribution

Recorded from Swartklip (False Bay) to the Durban area (18-51). Found as a component of sand-binding turfs in the lower eulittoral.

World distribution: South African endemic.

Syntype localities: Cape Agulhas and near mouth of Kowie River, Port Alfred (Silva et al. 1996).

Pachychaeta cryptoclada, detail of cells.

Pachychaeta cryptoclada, tetrasporangia in stichidium-like structures.

Pachychaeta cryptoclada, habit.

Pachychaeta cryptoclada. 1. Habit of tetrasporangial plant. 2. Detail of main axis (note stunted laterals). 3. Cross section. 4. Tetrasporangia. Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Rhodomelaceae

Placophora J. Agardh

Vegetative thallus prostrate, foliaceaous, formed by lateral fusion of polysiphonous axes. Erect cylindrical polysiphonous branches often forming on thallus surface, some of these becoming reproductive. Segments with five pericentral cells, two ventral, one dorsal. Every segment in principle producing a branch, branches arranged in pairs on alternating sides. Thallus attached by rhizoids cut off from ventral pericentral cells. Reproductive structure developing on erect, free, radially symmetrical branches produced either from margins of prostrate axes or adventitiously from dorsal pericentral cells on thallus margins. Fertile filaments cylindrical or slightly compressed, with ca 7-10 pericentral cells. Tetrasporangia one per segment in dorsal straight series, with two cover cells. Spermatangia in conical heads that develop from trichoblasts on some subapical segments. Cystocarps spheroidal to urceolate, usually one per free branchlet. Three species are currently recognized, two of which occur in South Africa.

Key to species

1a. Free polysiphonous filaments rarely more than 0.5 mm long

P. binderi

1b. Free polysiphonous filaments up to 5 (-10)mm or more

P. monocarpa

Order Ceramiales

Family Rhodomelaceae

Placophora binderi (J.Agardh) J.Agardh 1863: 1138-1139

Plants epiphytic or epizoic, dark red to blackish, forming a foliose crust up to a few cm in diameter, with lobed margins. Structure of laterally fused polysiphonous branches arising usually from every segment, with two branches to the left and two to the right. Segments with five pericentral cells, two dorsal, three ventral. Fertile polysiphonous filaments up to 0.5 mm long, arising in usually dense tufts along thallus margins. Tetrasporangia ca 55 µm in diameter, in all but 3-4 most proximal segments of filaments up to 25 segments long. Spermatangial heads arranged radially on short free filaments , conical, ca 50 x 150 µm. Cystocarps globose to ovate, on short free filaments.

Collections, ecology and regional distribution

Recorded from the Cape Peninsula to northern KwaZulu-Natal (17-58). Epiphytic, usually on Codium species (e.g. C. platylobuim, C. duthiae), also on other larger algae including Zonaria subarticulata; epizoic on Pyura stolonifera.

Worldwide distribution: Also recorded from Inhaca Island (Mozambique), Japan, Australia, New Zealand, Indonesia, Peru and Tristan da Cunha (Guiry & Guiry 2011).

Type locality: Cape of Good Hope, South Africa (Silva et al. 1996).

Note: P. binderi is described in detail by Scagel (1953).

Placophora binderi: foliose thallus with tetrasporangial filaments. Removed from surface of a Codium sp., along with some of the (green) utricles.

Placophora binderi: tetrasporangial filaments on thallus – stained slide material.

Placophora binderi: tetrasporangium – stained slide material.

Placophora binderi. 1. Cross section of foliaceaous thallus. 2. Thallus margin in surface view. 3. Tetrasporiferous filaments (prostrate thallus in oblique section). Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Rhodomelaceae

Placophora monocarpa (Montagne) Papenfuss 1956: 73-74

Prostrate thallus dark red to blackish, forming a foliose crust up to several cm in diameter on the host, Ecklonia maxima. Vegetative structure essentially the same as that of P. binderi. Fertile filaments numerous, giving the thallus a velvety appearance; free filaments up to 5 (-10) mm long, compressed. Tetrasporangia ca 60 µm in diameter, in long straight series distal to the third to twelfth segment. Spermatangial stichidia arising in radial series on a number of subapical segments, conical, ca. 200 x 50 µm. Cystocarps usually one per erect filament, urceolate, ca. 400 x 200 µm, with narrow ostiole.

Collections, ecology and regional distribution

A common epiphyte on Ecklonia maxima, and therefore found where E. maxima occurs (1-22). Although E. maxima has recently appeared at De Hoop (24), we do not know if P. monocarpa is present there. Pocock (1953) recorded it from drift in the Port Elizabeth area, but that merely confirms the great distances travelled by floating thalli of E. maxima.

Worldwide distribution: Also known from Namibia.

Type locality: Cape of Good Hope (Silva et al. 1996).

Notes: 1. This species was previously known as Placophora eckloniae Pocock.
2 Stegenga et al (1997) record a specimen of somewhat similar gross morphology, growing on Ecklonia radiata from the Three Sisters – Port Alfred area, but note that it showed a somewhat different branching pattern and could not be identified with certainty because it was infertile.

Placophora monocarpa: stained slide preparation of west coast material with tetrasporangial filaments.

Placophora monocarpa: stained slide preparation showing detail of tetrasporangial filament .

Placophora monocarpa. 1. Apex of prostrate thallus. 2. Detail of thallus, dorsal view. Reproduced from Stegenga et al. (1997).

Placophora monocarpa. 1. Tetrasporangia. 2. Antheridial heads. 3. Cystocarp. 4. Optical section of cystocarp, showing carposporophyte. Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Rhodomelaceae

Kentrophora natalensis (J.Agardh) S.M.Wilson & Kraft in R.J.F. Henderson, S.M. Wilson & Kraft 2001: 175

Plants dark red to blackish, erect, up to 20 cm tall, comprising somewhat tangled bushy mass of ligulate branches with dentate margins. Attached by discoid holdfast. Erect axes 0.5 – 1 mm wide, irregularly branched; marginal teeth (determinate branchlets) about 0.6 mm long, opposite, curved towards branch apex, bearing sharp dorsal spine about 100 µm long. Central axial filament surrounded by 6 pericentral cells, medulla of up to 5 cell layers and cortex of 2-3 layers; proximal axes with secondary cortication; trichoblasts at apices of branches and marginal teeth, dichotomously branched. Tetrasporangia in lanceolate stichidia borne near apices of marginal teeth. Sexual plants not known.

Collections, ecology and regional distribution

Subtidal, recorded from Dwesa along the whole KwaZulu-Natal coast (44-58).

Worldwide distribution: South African endemic.

Type locality: Port Natal (Durban), South Africa (Silva et al. 1996).

Note: previously known as Plectrophora natalensis (J. Agardh) Wilson & Kraft (2000).

Kentrophora natalensis, Mzamba.

Kentrophora natalensis, whole thalli.

Kentrophora natalensis, frond detail.

Order Ceramiales

Family Rhodomelaceae

Neosiphonia sertularioides (Grateloup) K.W. Nam & P.J. Kang 2012: 87, figs 51-53

Plants creeping, the apices ascending, up to 1(-2) cm tall. Axes attached by unicellular haptera cut off from the pericentral cells. Laterals of exogenous origin, at intervals of 4 – 7 segments, in principle indeterminate, subtended by a trichoblast. Trichoblasts unbranched. Segments with four pericentral cells, without cortication. Segments to ca. 100 µm in diameter, in creeping filaments about 1.5 times longer than broad. In ascending filaments segments shorter than broad, the apical cells ca. 12.5 µm in diameter.

Tetrasporangia in long series subapically, shifting their position at intervals of ca. 4 segments. Sporangia ca. 55 µm in diameter, with only two long cover cells. Male stichidia at intervals of 2 segments. Stichidia accompanied by a single or once-forked sterile filament. Stichidia ca 100 x 25 µm, without sterile cells at the top. Cystocarps nearly globose, about 250 µm in diameter at maturity, ostiole surrounded by small cells (ca. 12.5 µm).

Neosiphonia differs from Polysiphonia in a number of characters (see Kim & Lee 1999). Morphological characters that are relatively easy to discern include: (in Neosiphonia) lateral branches arising on successive segments, erect indeterminate branches developing from the main axes and tetrasporangia in spiral series. In Polysiphonia lateral branch initials are separated by one to several segments, erect branches develop from a prostrate basal system, and tetrasporangia are “arranged in straight series on determinate branches” (Kim & Lee 1999).

Collections, ecology and regional distribution

Recorded from Jongensfontein to Double Mouth (26-43). Intertidal, including rock pools, on encrusting corallines, and in Scutellastra cochlear (limpet) gardens.

World distribution: virtually worldwide on temperate and tropical coasts (Guiry & Guiry 2016).

Type locality: Cette (Sète, Hérault), France (Womersley 1979).

Note 1. formerly known as Polysiphonia flaccidissima Hollenberg (Mamoozadeh & Freshwater 2012).

Note: 2. A smaller form of this species is sometimes found growing epizoically on the south coast. Thalli are repent (creeping), with ascending apices up to 2.5 mm tall, and primary laterals every 7-12 segments. Trichoblasts often only at the bases of laterals, usually unbranched, sometimes once or twice branched. Tetrasporangia ca. 45 µm in diameter, fertile segments with only two long cover cells. Other reproductive structures not seen. Other dimensions similar to our specimens of N. sertularioides as described above.

Neosiphonia sertularioides. Whole mount (stained slide).

Neosiphonia sertularioides. Apices of male thallus (stained slide).

Neosiphonia sertularioides. Apices of tetrasporangial thallus (stained slide).

 Neosiphonia sertularioides. Detail of spermatangial stichidia( stained slide).

Neosiphonia sertularioides. Detail of cells. (stained slide).

Neosiphonia sertularioides. Young cystocarp (stained slide).

Order Ceramiales

Family Rhodomelaceae

Polysiphonia Greville

Plants filamentous, freely branched, with terete axes and branches, erect or partly prostrate; attachment of prostrate parts by rhizoids or haptera. Number of pericentral cells in genus varying between 4 and 24, fairly consistent for a species; secondary cortication present or absent. The origin of branches varies within the genus: 1) Exogenous – branches originate below the thallus apex, cut off from the central axial cell before any pericentral cells form. 2) Cicatrigenous – arising from the basal cell of a trichoblast. 3) Endogenous – originating from the central axial cells after the pericentral cells have formed.

A distinction between determinate and indeterminate laterals is clear in some species but absent in others. Trichoblasts may be present or absent in vegetative thalli. Tetrasporangia are formed in little-differentiated thallus sections, one per segment, in a straight series, each with two or three cover cells. Cystocarps are urceolate to globose. Antheridial stands are cylindrical or cylindro-conical.

Found almost worldwide in marine and estuarine environments: epilithic, epiphytic and epizoic, with 222 currently recognized species (MD Guiry in Guiry & Guiry 2016).

Note 1: Polysiphonia may be confused with other south coast genera such as Lophosiphonia, Neosiphonia and Pterosiphonia. However, Lophosiphonia has unlimited growth of dorsiventral prostrate branches and a limited system of uprights that develop endogenously, and Pterosiphonia has flattened, bilaterally symmetrical branches (Guiry & Guiry 2016). Neosiphonia differs from Polysiphonia in a number of characters (see Kim & Lee 1999). Morphological characters that are relatively easy to discern include: (in Neosiphonia) lateral branches arising on successive segments, erect indeterminate branches developing from the main axes and tetrasporangia in spiral series. In Polysiphonia lateral branch initials are separated by one to several segments, erect branches develop from a prostrate basal system, and tetrasporangia are “arranged in straight series on determinate branches” (Kim & Lee 1999).

Note 2: Polysiphonia subtilissima  Montagne 1840: 199

We have not seen this species, which is recorded by Lambert et al. (1987) from mangroves north of the Mbashe River to northern KwaZulu-Natal, and they describe it as follows: “Thallus less than 1 mm high, maroon, branching infrequent, polysiphnous throughout. Horizontal axes are attached by long unicellular rhizoids. Trichoblasts infrequent, colourless and unbranched. Four pericentral cells per axial cell.” (See Lambert et al. (1987, Fig. 4c and 4d). It is reported as associated with mangroves from certain estuaries including Xora (just north of the Mbashe River) to Kosi Bay in northern KwaZulu-Natal (45-58) (Lambert et al. 1987). They note that it is “a common associate of the bostrychietum”.

This species is reported from temperate and tropical localities, virtually worldwide in saline to estuarine habitats and even in some freshwater habitats (W. Guiry in Guiry & Guiry 2016). The type locality is Cayenne, French Guiana (Silva et al. 1996).

Key to species

1a. Species with more than four pericentral cells

2

1b. Species with four pericentral cells

4

2a. Estuarine species, with 5 or 6 pericentral cells; some secondary cortication present (in older specimens)

3

2b. Species of full salinity, with ca. 8 pericentral cells

P. foetidissima

3a. Plants epilithic. 5 or 6 pericentral cells; axes branched every 4-10 segments. Every segment near the apices with a trichoblast

P. kowiensis

3b. Plants epi-/endophytic on (Codium sp.) 5 pericentral cells; axes scarcely branched, vegetative trichoblasts rare

Polysiphonia sp 1.

4a. Pericentral cells with chloroplasts on radial walls only

P. incompta
(and see note on
Polysiphonia sp 3
under P. incompta)

4b. Pericentral cells with chloroplasts on radial and peripheral walls

5

5a. Plants mainly prostrate or with very well-developed prostrate system

6

5b. Plants with well-developed, branched erect axes

7

6a. Prostrate axes up to 65 µm in diameter and with down-curved tips, erect filaments in a dorsal row, unbranched or with a few short laterals

P. scopulorum

6b. Prostrate axes up to 175 µm in diameter and with upward-curving tips, erect filaments not in dorsal row, often with branches

P. namibiensis

7a. Filaments up to 50 µm wide, apices without trichoblasts

Polysiphonia sp 2

7b. Creeping filaments ca 200 µm wide, uprights 150-170 µm wide near middle, apices with trichoblasts

Polysiphonia sp 4

Order Ceramiales

Family Rhodomelaceae

Polysiphonia foetidissima Cocks ex Bornet 1892: 314

Plants creeping, the apices ascending , up to 5 (-10) mm tall, the creeping parts (much) longer. Axes attached by unicellular rhizoids, cut off from the pericentral cells, usually one or two per segment. Laterals of exogenous origin, at intervals of ca. 10-20 segments, in principle indeterminate. Trichoblasts at intervals of several segments, unbranched or with a single forking. Segments with ca. 8 pericentral cells, without cortication. Segments to 150 µm in diameter (in creeping parts), throughout most of the thallus slightly longer than broad, in the creeping parts somewhat shorter than broad.

Tetrasporangia in several subapical segments, in orthostichous rows of about 3-6 segments. Mature sporangia round, ca. 70 µm in diameter, with only two long cover cells. Male stichidia up to 150 x 37.5 µm, accompanied by a sterile branch of the trichoblast. Stichidia at intervals of a few segments. Female structures not seen.

Collections, ecology and regional distribution

Recorded from Hangklip (Western Cape) to Kei Mouth (19-43). Epilithic and epiphytic in the eulittoral zone and in rock pools, often in turfs.

World distribution: virtually worldwide on temperate and tropical coasts (MD Guiry in Guiry & Guiry 2016).

Lectotype locality: Plymouth, Cornwall, England (Maggs & Hommersand 1993).

Note: previously known as Polysiphonia tepida Hollenberg .

Polysiphonia foetidissima. Habit, stained microscope slide.

Polysiphonia foetidissima. Tetrasporangial thallus.

Polysiphonia foetidissima. Tetrasporangial thallus, stained slide.

Polysiphonia foetidissima. Detail of tetrasporangia, stained slide.

Polysiphonia foetidissima. Male thallus with spermatangial stichidia (stained slide).

Polysiphonia foetidissima. Basal axis with 1-2 attachment rhizoids per segment, originating from pericentral cells.

Polysiphonia foetidissima. Branch apices with trichoblasts.

Order Ceramiales

Family Rhodomelaceae

Polysiphonia incompta Harvey 1847: 44

Plants up to 6 cm tall (usually 2-3 cm), with a tangled mass of prostrate and erect filaments, attached by many rhizoids cut off from the pericentral cells of prostrate axes, often one or two rhizoids present per segment. Segments with four pericentral cells, without cortication. Chloroplasts in the pericentral cells concentrated along the radial cell walls, leaving the peripheral walls free (but see note below). Branching at intervals of 3 to many (over 20) segments, laterals exogenous. Young segments each with a branched or unbranched trichoblast. Filaments up to 400 µm across in prostrate axes, gradually decreasing towards the apex. Segments 0.5 – 2 times as long as broad.

Tetrasporangia in tortuous series in apical sections of the plant. Sporangia measuring up to 75 µm across, with two long cover cells. Male stichidia single on the suprabasal cell of the trichoblast, at maturity ca. 250 x 60 µm, without sterile apex. Cystocarps nearly globose, ca. 500 µm in diameter at maturity, with an ostiole surrounded by a ring of large cells (to 70 µm broad).

Collections, ecology and regional distribution

Recorded along the entire coast of South Africa (1-58). A common species, found (usually in turfs) throughout the eulittoral zone, in rock pools and in the shallow sublittoral. Epilithic, epiphytic and epizoic. Also recorded from some estuaries, attached to fringing vegetation.

World distribution: also recorded from Namibia and Mozambique (Rull Lluch 2002, Silva et al. 1996).

Type locality: near Muizenberg, False Bay, Western Cape Province, South Africa (Silva et al. 1996).

Note: We have collected a male plant of an entity that also has chloroplasts only on the radial cells walls, but which has a thinner creeping base (250 µm) and larger stichidia (to 375 µm long), which is briefly described and illustrated as Polysiphonia sp 3. We are however, uncertain of its affinities.

Polysiphonia incompta. 1. Thallus apex. 2. Prostrate axes with haptera. 3. Tetrasporangia. 4. Cystocarps, one in optical section showing carposporophyte (reproduced from Stegenga et al. 1997).

Polysiphonia incompta, De Hoop.

Polysiphonia incompta, slide mount of female thallus with cystocarps.

Polysiphonia incompta, with spermatangial stichidia (stained slide).

Polysiphonia incompta, tetrasporangia.

Polysiphonia incompta, cell details.

Polysiphonia incompta, cystocarp.

Note: Polysiphonia sp. 3

We have a single, male specimen of an entity that also has the chloroplasts only on the radial cell walls, but has thicker axes and larger male stichidia than P. incompta. We are uncertain of its affinities and it is described and illustrated below.

Plants with creeping base up to 250 µm thick. Pericentral cells four, without cortication. Segments in the whole thallus about as long as broad. Pericentral cells with chloroplasts on the radial walls, not on the peripheral walls. Male stichidia relatively large, one, rarely two per stalk cell, dimensions up to 375 X 75 µm, without sterile terminal cells. Other reproductive structures not seen.

Polysiphonia sp. 3. Whole mount of male thallus. (stained slide).

Polysiphonia sp. 3. Apex of male thallus. (stained slide).

Polysiphonia sp. 3. Detail of spermatangial stichidia (stained slide).

Order Ceramiales

Family Rhodomelaceae

Polysiphonia kowiensis Stegenga, J.J. Bolton & R.J. Anderson 1997: 547

Plants up to 3 (-5) cm tall, erect, without creeping filaments. Segments with 5 or 6 pericentral cells, in the older axes surrounded by corticating filaments. Axes up to 500 µm in diameter, segments up to twice as long as broad. Axes branched at intervals of 4 – 10 segments. Apices with a short and unbranched trichoblast (or with one lateral) on every segment.

Tetrasporangia in long tortuous series in subapical segments, with two long and one short cover cells. Sporangia up to 100 µm in diameter. Male stichidia one per segment, on the second cell of the trichoblast, up to 250 µm long and 60 µm broad, sometimes with a sterile apex ca. two cells long. Cystocarps globular to broadly urceolate, up to 500 µm in diameter, ostiolar cells relatively small, to about 25 µm broad.

Collections, ecology and regional distribution

Only recorded in Langebaan Lagoon (west coast) and Kowie estuary and Kleinemonde Estuary on the south coast (13 and 39). Epilithic and apparently relatively rare; only in river mouths and lagoons with reduced salinity.

World distribution: South African endemic.

Type locality: Kowie Estuary, Eastern Cape Province (Stegenga et al. 1997).

Polysiphonia kowiensis. 1. Thallus apex. 2. Detail of older axis, showing beginning cortication. (Reproduced from Stegenga et al. 1997).

Polysiphonia kowiensis.

Polysiphonia kowiensis. Young cystocarps.

Polysiphonia kowiensis. Tettrasporangia.

Polysiphonia kowiensis. Mature cystocarps (stained slide).

Order Ceramiales

Family Rhodomelaceae

Polysiphonia namibiensis Stegenga et Engledow in Stegenga, Bolton et Anderson 1997: 550

Plants largely prostrate, apices erect. Erect part up to ca. 5 (-10) mm tall. Filament with 4 pericentral cells, without cortication. Creeping axes up to 175 µm in diameter, erect axes usually not exceeding 100 µm; segments in creeping filaments up to about as long as broad, in erect axes much shorter. Creeping filaments attached by unicellular haptera in open connection with the pericentral cells, usually at intervals of 2 or 3 segments. Laterals developing at intervals of 3 or 4 segments, the majority remaining determinate and unbranched, a minority developing into indeterminate branches.

Tetrasporangia in the lower half of the determinate branchlets, in a single row, each with two long and one short cover cell. Sporangia at maturity somewhat flattened, up to 60 µm broad and 45 µm tall. Male stichidia borne at the apices of indeterminate as well as determinate axes, 1 stichidium per segment. Stichidia up to ca. 250 µm long and 50 µm broad, usually with only one terminal sterile cell. Female specimens not seen on the south coast, but known from the west coast.

Collections, ecology and regional distribution

Recorded on the South African coast from Olifantsbos (west side of the Cape Peninsula) to the Kei Mouth area (17-43). This species is common in Torra Bay, Namibia, and “it is not known if it occurs between Namibia and the Cape Peninsula” (Stegenga et al. 1997). It occurs in the lower eulittoral and sublittoral fringe in wave-exposed areas.

World distribution: also recorded from Namibia (Stegenga et al. 1997).

Type locality: Hottentots Bay, Namibia (Stegenga et al. 1997).

Polysiphonia namibiensis. 1. Microscopic habit. 2. Thallus apex. 3. Detail of prostrate axis with haptera and bases of laterals. (Reproduced from Stegenga et al. 1997).

Polysiphonia namibiensis. Tetrasporangial thallus.

Polysiphonia namibiensis.

Polysiphonia namibiensis. Detail of prostrate axis showing rhizoids arising every 2-3 segments.

Polysiphonia namibiensis. Rhizoid (on right) originating from pericentral cell; young upright on left.

Polysiphonia namibiensis. Male thallus.

Polysiphonia namibiensis. Detail of spermatangial stichidia.

Polysiphonia namibiensis. Branch apex with trichoblasts.

Order Ceramiales

Family Rhodomelaceae

Polysiphonia scopulorum Harvey 1855: 540

Plants mainly prostrate, with the apex of the main axes slightly turned downward. Creeping filaments attached by haptera (not arising from every segment ) continuous with a pericentral cell. Segments without cortication, with four pericentral cells about 1 – 2 times as long as broad, but much shorter near the apices of the plant. Erect filaments to about 2-3 mm tall, unbranched or with a few short laterals. Laterals of endogenous origin, mature laterals with a few trichoblasts. Mature (repent) axes to 65 µm in diameter, tapering to ca. 20 µm in the apex. Plants on the south coast are smaller than on the west coast, where erect axes grow to 20 mm tall and prostrate axes are up to 120 µm thick. Reproductive structures not seen in south coast specimens, but known in west coast material (Stegenga et al. 1997).

Collections, ecology and regional distribution

Recorded from the Cape Peninsula along the south coast to northern KwaZulu-Natal (15-58). Found in algal turfs, usually in the lower eulittoral; epilithic or epizoic on animal shells.

World distribution: virtually worldwide on temperate and tropical coasts (W. Guiry in Guiry & Guiry 2016).

Type locality: Rottnest Island, Western Australia (Silva et al. 1996).

Polysiphonia scopulorum. 1. Microscopic habit. 2. Apex of prostrate axis (note endogenous origin of erect branches). Reproduced from Stegenga et al. (1997).

Polysiphonia scopulorum. 1. Microscopic habit. 2. Apex of prostrate axis (note endogenous origin of erect branches). Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Rhodomelaceae

Polysiphonia sp 1

Plants up to 2 cm tall, comprising uprights arising from an endophytic base (in Codium tenue); from the point of emergence immediately producing a few erect axes. From there, thallus producing branches at intervals of many (up to more than 30) segments. Plants. Vegetative trichoblasts rare. Segments with 5 pericentral cells, older segments with some cortication, diameter up to 400 µm.

Tetrasporangia in long tortuous subapical series, ca. 60 µm in diameter, with 2 long and 1 short cover cells. Male stichidia usually single, ca. 225 x 50 µm, without sterile apex, accompanied by a small sterile filament. Cystocarps about spherical, ca. 250 – 400 µm in diameter. Carposporangia lacrimate, ca. 75 µm long.

Collections, ecology and regional distribution

Only found in the estuary at Double Mouth (43), on Codium tenue and calcareous worm tubes.

Polysiphonia sp. 1. Whole mount (stained slide) showing base and rhizoids (left lower corner) that were immersed in tissue of host (Codium sp).

Polysiphonia sp. 1. Cystocarps.

Polysiphonia sp. 1. Detail of cystocarp.

Polysiphonia sp. 1. Spermatangial stichidia.

Polysiphonia sp. 1.Tetrasporangia.

Polysiphonia sp. 1. Basal rhizoids and one detached Codium utricle from the host.

Order Ceramiales

Family Rhodomelaceae

Polysiphonia sp 2

Plants with creeping prostrate base, erect axes up to 6 mm long, branched only in the proximal part; segments 1-2.5 times longer than broad, near the apices much shorter. Filaments ca 50 µm in diameter, with four pericentral cells. Apices without trichoblasts. Tetrasporangia in long orthostichous series, near the apices of filaments, ca. 40 µm in diameter, with two long and one short cover cells. Other reproductive structures not seen.

Polysiphonia sp. 2. Whole mount (stained slide, no. 1719).

Polysiphonia sp. 2. Cell detail (stained slide).

Polysiphonia sp. 2. Tetrasporangia (stained slide).

Polysiphonia sp. 2. Detail of tetrasporangia (stained slide).

Polysiphonia sp. 2. Apex of branch. (stained slide).

Order Ceramiales

Family Rhodomelaceae

Polysiphonia sp 4

Description based on a single slide specimen: Plants with creeping base ca. 200 µm wide, upright axes to ca. 13 mm tall and ca. 160 µm wide near the middle; four pericentral cells. Segments in erect axes 1.5-2.5 times as long as broad. Apices with trichoblasts; unbranched when arising close to tip, developing single fork slightly lower down the thallus.

Only female plant seen. Carposporangia ca. 270 µm long and 350 µm wide, carpospores clavate, ca. 75 µm long.

Collections, ecology and regional distribution

Known only from a single collection at Bird Island, Algoa Bay (38).

Polysiphonia sp. 4. Whole mount of female thallus (stained slide: no. 1967).

Polysiphonia sp. 4. Detail of female thallus (stained slide).

Order Ceramiales

Family Rhodomelaceae

Polyzonia elegans Suhr 1834: 739-740, pl. II: fig. 15

Plants dark red, up to 6 cm long, epiphytic, comprising branched polysiphonous axes bearing distichously arranged leaf-like laterals. Attached by rhizoidal pads arising from ventral pericentral cells. Axes with 6 pericentral cells surrounding axial filament; 100 – 150 µm in diameter, in places with ventral keel. Indeterminate axes corticated; determinate axes arising from every second segment in alternating pattern, forming leaf-like branches with four marginal teeth; trichoblasts absent. Tetrasporangia in dorsal series in distal segments of indeterminate axes, ca. 150 x 50 µm, one per segment, with 3 cover cells that become indistinct with cortication of the fertile segment. No sexual plants observed.

Collections, ecology and regional distribution

Recorded from Goukamma eastwards along the coast into Mozambique (29-58). Common as an epiphyte on various seaweeds in the lower eulittoral and shallow sublittoral, particularly Gelidium abbottiorum and G. pteridifolium.

World distribution: Mozambique, Western Australia (Guiry & Guiry 2011).

Type locality: Algoa Bay, South Africa (Silva et al. 1996).

Note: for detailed descriptions and illustrations of this species see Scagel (1953).

Polyzonia elegans (height ca. 20 mm).

Polyzonia elegans, detail of leaf-like branches.

Order Ceramiales

Family Rhodomelaceae

Pterosiphonia Falkenberg

Plants comprising prostrate and erect indeterminate axes, both polysiphonous; oriented dorsiventrally; erect axes bilaterally symmetrical, compressed to flattened, branching distichous and alternate; proximal segments of laterals in both systems of axes confluent with main axes, more strongly so in erect axes. Segments with five or more pericentral cells, uncorticated or corticated to varying degrees. Prostrate axes attached by rhizoids cut off from pericentral cells, with multicellular attachment pads. Tetrasporangia in distal parts of thallus, one per segment. Antheridial stands cylindro-conical, subterminal. Cystocarps ovoid to spheroid, subterminal. Twelve species are recognized worldwide (Guiry & Guiry 2016), of which four are present on the south coast, as well as one other entity that remains undescribed.

Key to species

1a. Axes terete, uncorticated, segments with 8-12 pericentral cells

P. spinifera

1b. Axes compressed, segments with 5 (-6) pericentral cells, cortication present or absent

2

2a. Cortication in main axes 3-4 layers thick, thallus apices overtopped by young laterals

P. cloiophylla

2b. Cortication in main axes about one layer thick or incomplete; thallus apices not overtopped by young laterals

3

3a. Cortication complete; laterals confluent with main axes for basal 6-8 segments

P. stegengae

3b. Cortication either absent or incomplete; laterals confluent with main axis for basal 2-3 or 3-4 segments

4

4a. Cortication incomplete; laterals confluent with main axis for basal 3-4 segments

P. stangerii

4b. Cortication absent; laterals confluent with main axis for basal 2-3 segments

P. sp. indet.

Order Ceramiales

Family Rhodomelaceae

Pterosiphonia cloiophylla (C.Agardh) Falkenberg in Schmitz & Falkenberg 1897: 443

Plants dark red to brown or black, varying in size from short (2 cm) turfs to larger (to 20 cm) and more individual plants. Thallus pinnate, compressed; main axis prominent, up to 1.5 mm wide, alternately branched with laterals arising every 2-4 segments, laterals re-branched 2-3 times. Segments with 5 (-6) pericentral cells, heavily corticated, segmentation obscured in older parts. Laterals confluent with main axis for proximal 2-3 segments. Vegetative trichoblasts absent. Tetrasporangia in apparently rectilinear series in apical parts of laterals; up to 80 µm in diameter, with two long and one short cover cell. Antheridial stands cylindro-conical, sub-apical on laterals; male trichoblasts lacking sterile parts. Cystocarps globose, subapical on laterals.

Collections, ecology and regional distribution

Recorded from the whole west and south coasts to the Port Edward area of KwaZulu-Natal (1-48). Common in the lower eulittoral and shallow sublittoral zones in exposed and semi-exposed areas, often in turfs and sometimes forming a zone at the low tide level.

World distribution: Namibia, Amsterdam and St. Paul Islands, Oman, Pakistan (Guiry & Guiry 2011).

Type locality: Cape of Good Hope, South Africa (Silva et al. 1996).

Pterosiphonia cloiophylla.

Pterosiphonia cloiophylla showing cortication to near tips.

Pterosiphonia cloiophylla , cystocarps.

Pterosiphonia cloiophylla, antheridial stands.

Pterosiphonia cloiophylla , cross-section showing cortication, axial cell and pericentral cells.

Pterosiphonia cloiophylla . 1. Habit. 2. Cross section of main axis. 3. Tetrasporiferous thallus apex. 4. Tetrasporangia. Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Rhodomelaceae

Pterosiphonia spinifera (Kützing) Ardré 1967: 37, 41, pl. III: fig. 3

Plants dark red to blackish, comprising terete filamentous prostrate and erect axes, erect axes up to 2 cm tall, (mostly once-) pinnately branched; laterals alternate, arising from every second segment, most laterals simple, determinate, incurved when young, with an acute apex; indeterminate laterals infrequent. Main axes 200 - 250 µm in diameter; main axis and laterals confluent for one segment only. Segments with 8-10 (-16) pericentral cells, uncorticated, segments about as long as broad. Elongated, slightly transparent cells visible in nodes of branches. Reproductive structures not seen in our material.

Collections ecology and regional distribution

Recorded from one subtidal site near Cape Hangklip in the Western Cape (Jackelman et al. 1991) to northern KwaZulu-Natal (19-58). Apparently occurs in the lower eulittoral and shallow sublittoral zones.

World distribution: Peru, Brazil, France, Spain (Guiry & Guiry 2011)

Type locality: Peru (Silva et al. 1996).

Note: There is some variation in the number of pericentral cells in South African specimens: 8-10 were recorded by Stegenga et al (1997) in a west coast (Cape Hangklip) specimen, 10-12 by Norris and Aken (1985) in Kwazulu-Natal specimens, and a specimen (BOL 14989) from Dome Bluff, Transkei, has up to 16 pericentral cells. In other respects these specimens appear very similar, even to the single semi-transparent cell lying below the node of each branch, which Norris and Aken noted in the Kwazulu-Natal plants. They also illustrate rows of single tetrasporangia, about 40 µm in size.

Pterosiphonia spinifera Port Alfred.

Pterosiphonia spinifera, cell detail (Hangklip, Western Cape).

Pterosiphonia spinifera, cell detail and semi-transparent nodal cell (Hangklip, Western Cape).

Pterosiphonia spinifera .  1. Erect axis. 2. Thallus apex. Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Rhodomelaceae

Pterosiphonia stangerii (J.Agardh) Falkenberg 1901: 270

Plants dark red to blackish, comprising extensive rhizomatous axes bearing erect branches ca. 20 mm high. Erect branches complanate, 2-3 times pinnately branched from every second or third segment in alternate series; bases of laterals confluent with main axis for three or four segments. Segments with five pericentral cells and secondary cortication that incompletely covers pericentral cells; segmentation visible in all parts of plant; axes compressed, with narrow “wings” mainly at junction of main axis and abaxial side of laterals; axes up to about 0.5 mm wide and about half as thick. Tetrasporangia in apparently rectilinear series in ultimate branches, with two long and one short cover cell, up to 80 µm in diameter. Antheridial stands cylindro-conical, subapical on laterals; male trichoblasts without sterile branches. Female reproductive structures not seen.

Collections ecology and regional distribution

Recorded from Swartklip (False Bay) along the south and east coasts to northern Kwazulu-Natal (18-58). Found in the lower eulittoral and shallow sublittoral zones.

Worldwide distribution: Southern African endemic: also recorded from Mozambique (Silva et al. 1996).

Type locality: Port Natal (Durban), South Africa (Silva et al. 1996).

Pterosiphonia stangerii, Kenton on Sea (stained slide material).

Pterosiphonia stangerii, Kenton on Sea, showing cell detail (stained slide material).

Pterosiphonia stangerii, Kenton on Sea, showing tetrasporangia (stained slide material).

Pterosiphonia stangerii, Kenton on Sea, showing details of tetrasporangia (stained slide material).

Pterosiphonia stangerii, Port Alfred, (stained slide material).

Pterosiphonia stangerii 1. Microscopic habit, showing prostrate and erect axes. 2. Apex of prostrate axis. 3. Apex of erect axis. 4. Mature segments. 5. Tetrasporangia. Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Rhodomelaceae

Pterosiphonia stegengae Savoie & G.W.Saunders 2016: 926, fig. 5

Plants dark red, compressed, erect axes bi-or tripinnately branched; laterals alternate, arising at intervals of ca. 3 segments. Axis up to 1 mm wide, 250 µm thick, laterals confluent with main axes for 6-8 segments; ultimate branches broadly triangular. Segments with five pericentral cells and incomplete cortication about one cell layer thick.

Tetrasporangia developing in straight series in short branches near apices of thallus (Savoie & Saunders 2016). Other reproductive structures not seen.

Collections, ecology and regional distribution

Recorded from Cape Hangklip (Jackelman et al. 1991) to East London (19-41).

Worldwide distribution: South African endemic.

Type locality: “Preekstoel, Stilbaai, Western Cape, South Africa." (Savoie & Saunders 2016).

Pterosiphonia stegengae (Bird Island, Algoa Bay).

Pterosiphonia stegengae (Bird Island), structure.

Pterosiphonia stegengae (Bird Island), structure of young branch.

Pterosiphonia stegengae. 1. Thallus apex. 2. Cross section. Reproduced from Stegenga et al. (1997: Plate 239, Figs 3-3, as Pterosiphonia sp.)

Order Ceramiales

Family Rhodomelaceae

Pterosiphonia sp. indet

Plants about 1 cm tall, red, complanate. Erect branches 2-3 times pinnately branched from every second or third segment in alternate series; bases of laterals confluent with main axis for two to three segments. Segments with five pericentral cells, completely uncorticated; segmentation visible in all parts of plants; transparent axial line usually visible though main branches; rows of outer cells on branches often somewhat transparent. No reproductive structures seen. Prostrate axes up to ca. 200 µm wide.

Collections, ecology and regional distribution

Recorded from Bird Island ( Algoa Bay) and Kini Bay near East London.

Note: This species was reported as P. parasitica from Bird Island (Anderson & Stegenga, 1989), a species which however is reported to have 6-7 pericentral cells. Although rather similar to P. stangerii in overall appearance, our entity is completely uncorticated and has rows of semi-transparent cells along the outside of many branches. Furthermore, the absence of cortication in the main axes reveals a thin transparent line formed by the spaces between pericentral cells.

Note: this taxon is not the same as Pterosiphonia sp. of Stegenga et al (1997): that species is now known as P. stegengae Savoie & Saunders.

Pterosiphonia sp., habit, stained slide (Kini Bay, west of East London).

Pterosiphonia sp., detail (Bird Island, stained slide).

Pterosiphonia sp., (Bird Island), cell detail (stained slide).

Pterosiphonia sp., (Kini Bay), branching and outer “clear” cells (stained slide).

Pterosiphonia sp., (Kini Bay, stained slide), prostrate axis with bilateral arrangement of young branches.

Order Ceramiales

Family Rhodomelaceae

Rhodomelopsis africana M.A.Pocock 1953: 34, fig. 1; pl. 5: figs A-F; pl. 6: figs A-C

Plants yellowish-brown to blackish, bushy, comprising prostrate basal system of rhizome-like branches with several erect axes up to about 10 (-20) cm tall. Segments with single axial filament surrounded by 7 pericentral cells, a layer of medullary cells and single-layered cortical cells of about 30 µm in diameter; cortication to very close behind apex, so that segmentation is obscured. Axes terete, up to 1 mm in diameter. Branching radial, laterals remaining unbranched and awl-shaped or developing into indeterminate branches. Trichoblasts absent in vegetative plants. Reproductive structures borne at apices of branches. Tetrasporangia in somewhat sickle-shaped stichidia, one per segment, about 80 µm in diameter, in single rows. Antheridial stands broadly sickle-shaped. Cystocarps globose, large (up to 1 mm in diameter), stalked, with short beak and ostiole.

Collections, ecology and regional distribution

Found from Brandfontein just west of Agulhas (Stegenga et al. 1997) along the south coast and east coasts (22-58). Often in sand-washed areas, in rock pools and the lower eulittoral and shallow sublittoral zones.

World distribution: Also recorded from Mozambique (Silva et al. 1996).

Type locality: Arniston, Western Cape, South Africa (Pocock, 1953).

Note: described in some detail by Pocock (1953).

Rhodomelopsis africana (scale bar 2 mm)

Rhodomelopsis africana, detail of apex (scale bar approximately 2 mm).

Rhodomelopsis africana, cross-section of axis showing axial filament and seven pericentral cells.

Rhodomelopsis africana, tetrasporangia.

Rhodomelopsis africana. 1. Habit. 2. Cross section of main axis. Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Rhodomelaceae

Streblocladia Schmitz in Engler and Prantl

Plants filamentous, comprising prostrate and upright systems of axes, freely branched, without rigid distinction between determinate and indeterminate branches. Number of pericentral cells in genus 4-18. Prostrate axes with rhizoids developing from pericentral cells, usually in proximal position; apices of all axes similar in structure, sympodial, new axes developing on inside of branches but position shifted somewhat from truly adaxial. Axes sometimes spirally twisted. No vegetative trichoblasts present. Tetrasporangia single in each segment, in (usually) straight series in distal branch ends. Antheridial heads cylindrico-conical, in double row on adaxial side of branches, one per segment. Cystocarps with short stalks, adaxial near branch apices. Of the six species that are currently recognised worldwide (Guiry & Guiry 2017), two are found on the South African south coast: in addition we record an apparently undescribed species.

Key to species

1a. Main axes to 10 cm tall, segments with 10-14 pericentral cells, some cortication in older parts, prostrate part limited or with single basal holdfast

S. corymbifera

1b. Main axes < 4 cm long, uncorticated, well-developed prostrate system

2

2a. Segments with 7-10 (usually 9) pericentral cells, thalli to a few cm tall

S. tenuissima

2b. Segments with 4 pericentral cells, thalli to 8mm tall

Streblocladia sp 1

Order Ceramiales

Family Rhodomelaceae

Streblocladia corymbifera (C.Agardh) Kylin 1938: 20-21

Plants red, erect, with single basal holdfast or limited prostrate part. Main axis up to 10 cm tall and 350 µm in diameter. Rhizoids when present developing from pericentral cells. Segments with 10-14 pericentral cells, about as long as broad or slightly shorter; older segments with some (rather insignificant) secondary cortication. Apex overtopped by incurved pseudolaterals. Tetrasporangia in dense fascicles of repeatedly branched filaments, irregularly aligned in branchlets, 70 µm in diameter, with two long and one short cover cell. Spermatangial heads forming one arm of a forked trichoblast; arranged adaxially on ultimate branchlets in a double row; conical, ca. 300 x 80 µm. Cystocarps globose to ovate, ca. 200 µm in diameter (Note that Stegenga et al. 1997 state that these dimensions are for cystocarps that “may be immature”.)

Collections, ecology and regional distribution

Recorded from the west coast to Goukamma (1-29), in tidal pools and the lower eulittoral zone. 

World distribution: Also recorded from Namibia (Wynne 1986b), Mozambique and Chile (Guiry and Guiry 2013).

Type locality: “Cape of Good Hope” (Silva et al 1996).

Streblocladia corymbifera, scale bar ca. 1mm (west coast specimen).

Streblocladia corymbifera, (west coast specimen).

Streblocladia corymbifera, spermatangial heads.

Streblocladia corymbifera, tetrasporangial branchlets.

Streblocladia corymbifera, showing pericentral cells (stained specimen).

Streblocladia corymbifera, tetrasporangia in spiral arrangement.

Streblocladia corymbifera 1. Thallus apex. 2. Detail of (lightly corticated) axis. 3. Spermatangial heads. Reproduced from Stegenga et al. (1997).

Streblocladia corymbifera 1. Tetrasporangia. 2. Cystocarps. Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Rhodomelaceae

Streblocladia tenuissima M.A.Pocock 1953: 40-41, figs. 3, 5, pl. 6: fig. D; pl. 8: figs. A-F

Plants bright red, slender, epiphytic, comprising prostrate creeping axes and upright axes; branching sparse below and more prolific distally, pseudodichotomous, laterals growing almost as strongly as main axis. Segments with 7-10 (usually 9 ) pericentral cells, about 1.5 times as long as broad, uncorticated; particularly in sterile parts somewhat twisted. Tetrasporangia about 70 µm in diameter, in fertile tufts of branches at ends of free axes, one per segment, in rectilinear series. Antheridial stands broadly sickle-shaped, borne on tufts of branchlets near ends of free axes. Cystocarps globular, stalked, usually borne adaxially, up to 300 µm in diameter.

Collections, ecology and regional distribution

Recorded from Keurboomstrand to Cove Rock near East London (31-41). Epiphytic on other red algae (e.g. Rhodomelopsis africana, Tayloriella, Pterosiphonia), usually in sand-washed localities , in rock pools of lower eulittoral zone.

World distribution: South African endemic.

Type locality: Cove Rock, near East London (Pocock 1953).

Note: Pocock (1953) points out that the fine red, hair-like branches of this species are characteristically visible as waving in the water a few cm above the host thallus.

Streblocladia tenuissima, apices of axes (Keurboomstrand specimen – stained slide).

Streblocladia tenuissima, branch junction showing pericentral cells (stained slide).

Streblocladia tenuissima, rhizoids (often two per segment) (stained slide).

Streblocladia tenuissima, tetrasporangia (stained slide).

Streblocladia tenuissima, male heads (antheridial stands) (stained slide).

Streblocladia tenuissima, showing antheridia on forked heads with trichoblasts (stained slide).

Streblocladia tenuissima, cystocarps (stained slide).

Streblocladia tenuissima, detail of cystocarps and stalks (stained slide).

Order Ceramiales

Family Rhodomelaceae

Streblocladia sp 1

Plants slender, epiphytic, forming a fine red turf a few to about 8mm tall on host algae; thalli comprising prostrate creeping axes and upright axes, branching sparse, pseudodichotomous. Segments with four pericentral cells throughout, uncorticated, prostrate axes about 150 µm in diameter, upright axes slightly narrower and narrowing distally to ca. 35 µm about five segments behind the apices. Prostrate axes attached by rhizoids cut off from proximal side of pericentral cells, often two rhizoids per segment. Tetrasporangia 40-45 x 45-50µm, one per segment, in linear series towards the apices of upright branches which become slightly thicker in fertile areas. antheridial stands cylindrical, arising from one branch of a forked trichoblast. Cystocarps with short stalk, ostiolate, when mature about 250 µm in diameter and somewhat proximal on upright axes.

Collections, ecology and regional distribution

So far only collected at Mkambati and Mbotyi, as epiphytes on Jania sp. and Codium spp. (47).

World distribution: SA endemic?

Streblocladia sp I, apices of axes (BOL148496).

Streblocladia sp I, rhizoids – proximal, often two per segment (BOL148496).

Streblocladia sp I, mature cystocarp near basal end of upright (BOL148496).

Streblocladia sp I, branch junction, four pericetral cells (BOL148496).

Streblocladia sp I, cell detail (BOL148496).

Streblocladia sp I, detail of cystocarp with carpospores (BOL148496).

Streblocladia sp I, tetrasporangia (BOL148496).

Streblocladia sp I, young antheridial stand on upright axis.

Order Ceramiales

Family Rhodomelaceae

Symphyocladia marchantioides (Harvey) Falkenberg in Schmitz & Falkenberg 1897: 444

Plants comprising prostrate stoloniferous axes and erect upright blade-like axes up to about 10 mm tall. Upright axes foliaceous, comprising laterally fused branches, confluent with prostrate axes or somewhat stipitate; fertile marginal portions of blades becoming filamentous. Plants dorsiventral, ventral cells slightly larger than dorsal cells; some ventral pericentral cells cutting off haptera. In a Western Cape specimen, segments reported to have 4-5 pericentral cells and some cortication from flanks of the filaments, especially on dorsal side of thallus. In other parts of world, segments with 6-8 pericentral cells, and no cortication. Tetrasporangia in more or less de-coalesced margins of fronds, one per segment, up to 70 µm in diameter with two long and one short cover cell. Sexual reproductive structures not seen.

Collections, ecology and regional distribution

Recorded from Cape Hangklip, ca 100 km west of Agulhas, to northern Kwazulu-Natal (19-58). Found in the lower eulittoral and sublittoral zones.

World distribution: Also found in Italy, the Azores and parts of the Pacific including New Zealand and Australia (Guiry & Guiry 2013).

Type locality: Hawke’s Bay, New Zealand (Silva et al. 1996).

Note: The Kwazulu-Natal specimens illustrated by Norris and Aken (1985) and De Clerck et al. (2005) are very similar, and somewhat different to those described by Stegenga et al. (1997) from Cape Hangklip: in the latter the axes and laterals are described as “completely confluent”.

Symphyocladia marchantoides, part of stained slide specimen (Cape Hangklip, Western Cape).

Symphyocladia marchantoides, part of stained slide specimen showing tetrasporangia (Cape Hangklip, Western Cape).

Symphyocladia marchantoides, detail of tetrasporangia, stained slide.

Symphyocladia marchantoides, cell detail- stained slide specimen (Cape Hangklip, Western Cape).

Symphyocladia marchantoides. 1. Apex of fertile blade. 2. Detail of thallus apex. 3. Cross section of blade. 4. Tetrasporangia. Reproduced from Stegenga et al. (1997, plate 244, as Symphyocladia cf. marchantioides).

Symphyocladia marchantoides. 1-2. Surface view of older thallus, providing view of ventral (1) and dorsal (2) pericentral cells. Reproduced from Stegenga et al. (1997, plate 244, as Symphyocladia cf. marchantioides).

Order Ceramiales

Family Rhodomelaceae

Tayloriella tenebrosa (Harvey) Kylin 1938: 18-19, figs. 9A-C.

Plants blackish, differentiated in to prostrate and erect filaments, growing in turf-like clumps, up to about 50 mm tall. Prostrate axes attached by numerous rhizoids cut off from pericentral cells. Erect axes alternately branched, usually from every third segment; laterals simple or re-branched. Trichoblasts rare or absent in vegetative thalli. Segments with about 16 pericentral cells, uncorticated. Axes up to 250 µm in diameter, segments 0.5 – 1 times as long as broad. Tetrasporangia in rows in much-branched, often rather contorted laterals; 80 µm in diameter, with two long and one short cover cell. Antheridial stands cylindro-conical, subapical. Cystocarps subglobose, up to 1 mm in diameter.

Collections, ecology and regional distribution

Recorded from Doringbaai on the west coast to Mission Rocks/Cape Vidal (8-56). Common in algal turfs in the lower eulittoral zone, often sand-binding; also in intertidal pools.

World distribution: Also recorded from Angola (John et al. 2004) and Namibia (Rull Lluch 2002).

Type locality: Near Muizenberg, False Bay (Silva et al. 1996).

Note: Wynne (1985) discusses the relationship between members of the closely related genera Tayloriella and Pterosiphonia.

Tayloriella tenebrosa, Qologha (6 km east of Kei Mouth) (scale bar 1 mm).

Tayloriella tenebrosa, detail of apices.

Tayloriella tenebrosa, detail of pericentral cells.

Tayloriella tenebrosa, cross-section of axis.

Tayloriella tenebrosa, apical branching (stained slide).

Tayloriella tenebrosa, tetrasporangial branchlets.

Tayloriella tenebrosa, rhizoids arising from proximal ends of basal segments.

Tayloriella tenebrosa, detail of tetrasporangia.

Tayloriella tenebrosa. 1-2. Thallus apex (erect filaments). 3-4. Cross sections of main axis and branchlet respectively. 5. Tetrasporangia. Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Spyridiaceae

Spyridia Harvey

Thalli erect, with a clear distinction between indeterminate and determinate branches. Axial cells of indeterminate branches each cutting off a ring of periaxial (=nodal) cells; periaxial cells each cutting off two (internodal) cells in basipetal direction, the latter making a connection with the periaxial cells of the segment below. Cortication of (young) segments thus consisting of two transverse bands of cells of slightly different size and shape. Further cortication in older segments by development of rhizoidal cells. Cells of the determinate laterals each with a ring of nodal cells, with or without further development of cortication, but never in the manner of the main axes. Tetrasporangia on the nodes of the determinate branches, exserted, tetrahedrally divided. Spermatangia covering several segments in the proximal part of determinate laterals. Procarps and carposporophytes on short determinate laterals.

A genus of warm temperate seas, with 15 species currently recognised (Guiry & Guiry 2015), of which five are found on the south coast.

Key to species

1a. Segments usually with two determinate laterals

Spyridia
plumosa

1b. Segments with one determinate lateral

2

2a. Plants rather lax, with a single straight terminal spine on the determinate laterals

Spyridia
filamentosa

2b. Plants sturdy, with two or more spines on the determinate laterals, in part recurved

3

3a. Determinate laterals completely corticated

Spyridia
cupressina

3b. Determinate laterals not completely corticated, or at least the separate cortical bands clearly visible

4

4a. Determinate laterals usually with four terminal recurved spines

Spyridia
horridula

4b. Determinate laterals with a terminal straight and 1-4 subterminal recurved spines

Spyridia
hypnoides

Order Ceramiales

Family Spyridiaceae

Spyridia cupressina Kützing 1849: 668

Plants bushy, up to about 20 cm tall, irregularly branched, with evenly-spaced hooked branchlets in four rows. Axes rigid, with a central filament of large cells (about as long as broad) surrounded by ca. 16 periaxial cells, each of which produces two cells in basipetal direction that connect with the periaxials of the central cell below. Secondary cortication present at a very short distance below the thallus apex, obscuring the primary structure. In cross section the central axes nearly square, with about five layers of progressively smaller cells surrounding the central cell. Each central cell with a determinate branchlet of 12-16 cells, with complete cortication, and three terminal spines. Spines somewhat recurved. Main axes about 0.5 mm in cross section, determinate laterals to 2 mm long and 350 µm in diameter basally, gradually tapering to the apex. Determinate laterals usually in four rows but sometimes almost distichous. Indeterminate branches at intervals of several segments, replacing determinate branchlets.

Tetrasporangia on much smaller branches that appear to be adventitious on the axes of the plant. The fertile shoot systems are ca. 800 µm at maximum, the individual ramuli much shorter, the cortication is incomplete, often consisting of a single ring of cells. Tetrasporangia scattered on the branchlets, fully exposed, tetrahedrally divided and measuring ca. 75 µm in cross section. Spermatangia on identical small shoots, covering the segments completely, the basal four segments without spermatangia and with incomplete cortication. Carposporophytes usually enclosed in two ostiolate lobes ca. 600 µm in diameter, on a normal determinate lateral, subtended by a few small shoots with incomplete cortication. Carpospores ca. 37 µm in diameter.

Collections, ecology and regional distribution

Although records indicate a distribution from Cape Agulhas to the north of KwaZulu-Natal (22-58), De Clerck et al. (2005) consider this species to be restricted to the Eastern Cape coast and southern KwaZulu-Natal, where it is fairly common (see note).

World distribution: Otherwise reported from Kenya and Madagascar, but these records are questioned by De Clerck et al. (2005).

Type locality: Cape of Good Hope, South Africa (Silva et al. 1996).

Note: De Clerck et al. (2005) point out that this species can be confused with the tropical species Phacelocarpus tristichus, but the latter has a different anatomy and branchlets that are in three rather than four rows.

Spyridia cupressina, Glen Muir (near East London).

Spyridia cupressina, thallus tips.

Spyridia cupressina, thallus tips, showing banding on laterals.

Spyridia cupressina, cross section (stained slide).

Spyridia cupressina, cross section through axis and determinate laterals (stained slide).

Spyridia cupressina, male adventitious branchlets (stained slide).

Spyridia cupressina, tetraspore-bearing adventitious branchlets (stained slide).

Spyridia cupressina, cystocarps and released carpospores (stained slide).

Order Ceramiales

Family Spyridiaceae

Spyridia filamentosa (Wulfen) Harvey in Hooker 1833: 337

Plants (in South Africa) usually small, rarely reaching more than a few cm. Main axes distinct, lax, in vigorously growing parts with indeterminate laterals at intervals of 5-8 segments. Central cells slightly shorter to slightly longer than broad, producing some 13 periaxial cells, each with two derivatives that connect with the periaxials of the segments below. Primary periaxials and their immediate derivatives remaining exposed for a long time, at a later stage becoming covered with a secondary epidermis. Main axes to ca. 400 µm in diameter. Each segment with one determinate lateral up to about 15 segments long, laterals spirally arranged along the main axis. Central cells of the determinate laterals slightly shorter to slightly longer than broad, with an incomplete cortex, the branchlets reaching a length of 1 mm and a diameter of ca. 55 µm, provided with a single straight spine. Reproductive structures not seen in South African material.

Collections, ecology and regional distribution

Recorded from False Bay to northern KwaZulu-Natal (17-58). This species is not common in South Africa; found occasionally in rock pools, the sublittoral fringe or below. There appear to be no species of Spyridia on the west coast or the Namibian coast.

World distribution: one of the most widespread Spyridia species, occurring virtually world-wide in tropical to warm temperate sites.

Type locality: Adriatic Sea (Silva et al 1996).

Note: De Clerck et al. (2005) point out the resemblance of this species to Spyridia plumosa, which however lacks terminals pines on the determinate laterals.

Spyridia filamentosa, Goukou estuary, Stilbaai (fresh material, under dissecting microscope).

Spyridia filamentosa, microscopic habit, Preekstoel, near Stilbaai (stained slide).

Spyridia filamentosa, detail of main axis with short laterals (stained slide).

Spyridia filamentosa, thallus apex (stained slide).

Spyridia filamentosa, short laterals with single terminal spine (stained slide).

Order Ceramiales

Family Spyridiaceae

Spyridia horridula F. Schmitz ex J. Agardh 1897: 15

Plants to 30 cm in height but usually 10-15 cm, rather stiff. Branching appears to be mainly in one plane, but near the apices four rows of laterals become apparent. Indeterminate branches generally alternating at intervals of 5-8 segments, the other segments with one determinate branchlet. Segments of the indeterminate branches with ca. 15 periaxial cells, each of which produces two derivatives that connect with the periaxials of the segment below. Main axis heavily corticated, increasing in diameter to over 1 mm, the segments becoming much wider than long. Determinate branchlets straight, consisting of 9-12 segments, with an incomplete cortication; cortical bands 2(-3) cells high, developing exclusively in acropetal and lateral direction from the periaxial cells. Apex of the determinate branchlets with (3)4 recurved stout spines. Reproductive stages not seen.

Collections, ecology and regional distribution

Recorded from Goukamma to Cape Vidal in KwaZulu-Natal (29-56). Found in rock pools, sublittoral fringe and below.

World distribution: South African endemic.

Note: Superficially similar to S. hypnoides, but with a nearly distichous branching pattern and no straight terminal spine (De Clerck et al. 2005).

Spyridia horridula, determinate laterals with four recurved spines. Stained slide, Goukamma oyster beds.

Spyridia horridula, detail of determinate laterals with four recurved spines. Stained slide, Goukamma oyster beds.

Spyridia horridula, indeterminate axes with determinate branchlets. Stained slide, Goukamma oyster beds.

Order Ceramiales

Family Spyridiaceae

Spyridia hypnoides (Bory) Papenfuss 1968: 281

Plants a few to 15 cm tall, branched frequently, with indeterminate laterals at short intervals. Indeterminate laterals and main axis with about 15 pericentrals, very soon covered with a secondary cortex, reaching a diameter of about 2 mm. Each segment with a straight determinate lateral up to ca. 800 µm long, 250 µm in diameter at the base, gradually tapering to the apex, consisting of up to 10-15 segments. Determinate laterals with a straight terminal spine and 1-4 subterminal, somewhat recurved spines. Cortication of determinate laterals (almost) complete, extending both in acropetal and basipetal direction. Tetrasporangia on proximal segments of determinate laterals, sessile on the central cells and completely exposed, measuring up to 60 µm across, tetrahedrally divided. Other reproductive structures not seen.

Collections, ecology and regional distribution

On the south coast only seen in Transkei, also found along the whole of the KwaZulu-Natal coast (43-58). Common in intertidal rock pools (De Clerck at al. 2005).

World distribution: Widespread in tropical to subtropical areas.

Type locality: Tamil Nadu, India (Silva et al. 1996).

Spyridia hypnoides, Mkambathi.

Spyridia hypnoides, apex with tetrasporangia, Mkambathi (stained slide).

Spyridia hypnoides, detail of apex with tetrasporangia, Mkambathi (stained slide).

Spyridia hypnoides, thallus apex. (Mzamba, stained slide).

Spyridia hypnoides, determinate laterals showing terminal spine and subterminal spines. (Mzamba, stained slide).

Spyridia hypnoides, part of thallus.

Order Ceramiales

Family Spyridiaceae

Spyridia plumosa F. Schmitz ex J. Agardh 1897: 14

Plants to ca. 10 cm tall, irregularly branching. Thallus perfectly distichous, each segment with two opposite determinate ramuli. Segments of the main axis with about 10 periaxial cells, each producing two (the basal cells of the determinate laterals three) derivatives in basipetal direction, which make contact with the periaxial cells of the segment below. Secondary cortication starting very soon, obscuring the initial pattern. Indeterminate axis increasing to ca. 1 mm thickness. Determinate laterals slender, ca. 75 µm in diameter, up to 30 segments (= 1.5 mm) long. Segments of the determinate laterals becoming somewhat longer than broad, incompletely corticated; cortical bands at the most three cells high, the periaxial cells lying in the middle. Determinate laterals tapering to a pointed cell. Reproductive stages not seen.

Collections, ecology and regionals distribution

Recorded between False Bay and Shelly Beach, southern KwaZulu-Natal (16-49). A rather rare species, found in rock pools and subtidally down to at least 19m (De Clerck et al. 2005).

World distribution: South African endemic.

Type locality: mouth of Kowie River, Port Alfred, Eastern Cape Province, South Africa (Silva et al. 1996).

Note: De Clerck et al. (2005) point out that this is the only South African Spyridia “lacking terminal spines on the determinate laterals and exhibiting an opposite branching pattern with two determinate branchlets being produced from a single segment”.

Spyridia plumosa (KwaZulu-Natal, Photo Tom Schils).

Spyridia plumosa thallus apex (Goukamma oyster beds, stained slide).

Spyridia plumosa older main axis with determinate laterals (Goukamma oyster beds, stained slide).

Spyridia plumosa older main axis with determinate laterals (stained slide).

Order Ceramiales

Family Wrangeliaceae

Anotrichium Nägeli

Plants up to about 10 cm long, filamentous, uncorticated. Thallus branching subdichotomous to secund, laterals borne singly, originating from the proximal ends of cells. Fourteen species are recognised (Guiry & Guiry 2015), of which two occur on the south coast.

Key to species

1a. Branching almost dichotomous; apical cells only ca. 15 µm in diameter

Anotrichium
furcellatum

1b. Branching largely secund; apical cells ca. 75 µm in diameter

Anotrichium
tenue

Order Ceramiales

Family Wrangeliaceae

Anotrichium furcellatum (J. Agardh) Baldock 1976: 560

Plants often forming loose-lying (and sterile) globose tufts several cm in diameter. Filaments uncorticated, forked at intervals of one to several segments, the branching subdichotomous. The lower segments with occasional rhizoids given off at both ends of the cells. Cells from 15 µm apically to ca. 300 µm in proximal parts, the length varying from ca. 30 µm apically to over one mm basally.

Reproductive structures rarely seen, tetrasporangia single, pedicellate, inserted at the upper end of cells. Sexual reproduction of South African material only known from the M.A. Pocock collection, on what would appear to be young plants: Female fertile filaments four-celled, the carposporophyte hemi-globose with two auxiliary cells developing. Involucral cells originating from the hypogenous cell (one) and the subhypogenous cell (five to seven).

Collections, ecology and regional distribution

In South Africa is restricted to a few estauries, from False Bay to the Port Alfred area (17-39). Apparently limited to (slightly) reduced salinities or sheltered habitats. The (early) finds of M.A. Pocock are among the very few world- wide that can claim to show the sexual reproduction of the species (Stegenga 1988).

Worldwide distribution: widespread in the Atlantic and Mediterranean, also reported from California and Japan (Guiry & Guiry 2015).

Type locality: Amalfi, Naples, Italy (Agardh 1842 in Guiry & Guiry 2015).

Anotrichium furcellatum, thallus apex. Reproduced from Stegenga et al. 1997.

Anotrichium furcellatum, micrograph of fresh material.

Anotrichium furcellatum, stained slide material, Kowie (not fertile).

Order Ceramiales

Family Wrangeliaceae

Anotrichium tenue (C. Agardh) Nägeli 1862: 399

Plants only in the west of the area up to 10 cm across, often rather smaller; epiphytic or entangled with other algae, sometimes epizoic on sedentary animals or not evidently attached to living substrata. Thallus unusual in this region in having (vegetative) branching from the proximal end of cells of the main axes. Digitate haptera arising from the same end of the cells. Main axis up to 300-400 µm in diameter, the cells to over 1 mm long. Apical and subapical segments shorter than broad, apical cells ca. 75 µm in diameter. Branching unilateral, especially when fertile branches are present, one every segment, fertile branches originating subapically. Trichoblasts often abundant on a few apical cells, consisting of two or three cells.

Tetrasporangia on a number of subapical cells, often replacing trichoblasts, terminal (or subterminal) on elongate pedicels, almost globose, ca. 100 µm in diameter, tetrahedrally divided. Spermatangial capitula in similar positions as tetrasporangia, although in slightly smaller numbers. Pedicellate clusters pyramidal. Carposporophytes one per segment, often a small number on consecutive filaments, the female fertile filaments being three-celled. The carposporophyte develops from the second cell, the undivided involucral cells from the hypogenous cell. Mature carposporophytes up to 500 µm, consisting of several gonimolobes.

Collections, ecology and regional distribution

Recorded from Doring Bay on the west coast to northern KwaZulu-Natal (8-58). Plants epilithic, epiphytic, or epizoic in the lower eulittoral and tidal pools and often in algal turfs.

World distribution: worldwide in tropical and temperate seas (Guiry & Guiry 2015).

Type locality: Venice, Italy (Silva et al. 1996).

Note: There may be some confusion between this species and Anotrichium secundum (Harvey ex J. Agardh) G. Furnari on our coast. Both may be present, but the characters that would separate them are slight (numbers of tetrasporangia in a whorl and the not very distinct character of tetrasporangium-insertion on the stalk cell, i.e. either truly terminal or subterminal). See also Stegenga (1985) for further details and illustrations of A. tenue.

Anotrichium tenue.  1. Microscopic habit. 2. Tetrasporangia. Reproduced from Stegenga et al. 1997.

Anotrichium tenue, female with developing carposporophytes, fresh material.

Anotrichium tenue, tetrasporangial, fresh material.

Anotrichium tenue, female with carposporophytes. Stained slide material, Woody Cape.

Anotrichium tenue, tetrasporangial. Stained slide material, Woody Cape.

Order Ceramiaceae

Family Wrangeliaceae

Dasyphila cryptocarpa (Holmes) F. Schmitz 1896: 8

Plants as found only a few cm high, regularly branched in a single plane. Determinate laterals simple, alternating, emitted every third segment, reaching a length of ca. 2 mm. Indeterminate laterals at irregular intervals, apparently developing from determinate branches a little distance below the thallus apex. Axes in cross section with a prominent central cell, surrounded by six periaxial cells, two of which are in the plane of branching and larger than the other four. Axis about 500 µm broad, and half as thick. Periaxial cells and immediate derivatives partly parenchymatous, but producing some filamentous tissue around the central axis and profusely on the outside, the epidermal cells only 3-4 µm in diameter. Thallus apices (main axis and laterals) clothed with short (4-6-celled) filamentous outgrowths. Reproductive specimens not seen.

Collections, ecology and regional distribution

Apparently a rare species, originally described from the Kowie area, also recorded at Mbotyi (39-48).

World distribution: South African endemic.

Type locality: near mouth of Kowie River, Port Alfred, Cape Province, South Africa (Silva et al. 1996).

Dasyphila cryptocarpa, apex of thallus. Stained slide material, Mbotyi.

Dasyphila cryptocarpa, longitudinal section of axis showing central filament. Stained slide material, Mbotyi.

Order Ceramiales

Family Wrangeliaceae

Griffithsia C. Agardh

Plants filamentous, ecorticate, in general subdichotomously branched. Thalli consisting of very large ellipsoid, clavate or cylindrical cells that are multinucleate. Tetrasporangia in whorls on intercalary cells, with or without a ring of involucral cells. Spermatangial heads whorled like the tetrasporangia (rarely capping an apical cell), with or without involucral cells. Female fertile filament three-celled, developing on an apical cell, but displaced by vegetative cells and moved into a lateral position. Carposporophytes with a central fusion cell and few to several gonimolobes, surrounded by involucral cells or two-celled involucral branches.

Thirty-nine species are currently recognized (Guiry & Guiry 2015). We recognize three on the south coast, including one that is apparently undescribed.

Key to species

1a. Filaments strongly moniliform. Carposporophyte with five involucral filaments from the basal cell of
the female fertile filament

Griffithsia sp.

1b. Filaments not obviously moniliform. Carposporophyte with six or more involucral filaments from the
basal cell of the female fertile filament or from the vegetative cell below

2

2a. Involucral cells of the carposporophytes about ten at maturity, originating from the vegetative cell
bearing the female fertile filament; tetrasporangia in clusters surrounded by involucral cells originating
directly from the vegetative cell

Griffithsia confervoides

2b. Involucral cells of the carposporophyte about six at maturity, developing from the basal cells of the
female fertile filament; tetrasporangia in clusters, the outer ring bearing involucral cells as well

Griffithsia subbiconica

Order Ceramiales

Family Wrangeliaceae

Griffithsia confervoides Suhr 1840: 281

Plants partly creeping, the erect parts rarely over 3 cm high. Axes subdichotomously branched at intervals of one to five segments, basal ramifications often trichotomous. Cells very large, up to 0.5 (-1) mm in diameter and up to 2 mm long, uncorticated, elongate and slightly swollen, somewhat broader at the top than at the base. Apical cells about 100 µm across when cut off. Plants attached by rhizoids from the acropetal end of the cells of the basal (creeping) part.

Tetrasporangial clusters in several verticils on (swollen) subapical cells, surrounded by up to 10 involucral cells, the latter originating from the subapical cell. Sporangia of different ages sitting on a small stalk cell, measuring up to 100 X 75 µm, tetrahedrally divided. Male stands in similar arrangement as tetrasporangia, also surrounded by several involucral cells. Male stands profusely branched and reaching a size of ca. 250 µm. Female stands developing on a subterminal cell, as a rule when three sterile cells are present on it. Female fertile axis three-celled, the subapical cell with a supporting cell and a sterile pericentral cell; supporting cell with a sterile cell and a four-celled carpogonial filament. As the carpogonium is fertilized the number of involucrals gradually increases to about ten. At the same time a number of (small) single cells or short filaments are cut off from the basal cell of the fertile filament. Carposporophytes with as many as four (-five) roundish gonimoblasts of different age, carpospores up to ca. 50 µm in diameter.

Collections, ecology and regional distribution

Recorded along the whole South African coast (1-58). Rather common along the south coast, in the low eulittoral and sublittoral zones. Although sometimes epiphytic, there is no close relationship with certain substrata and the species grows on inanimate substrata as well.

World distribution: Southern African endemic, also recorded from Namibia and Mozambique.

Type locality: "Falsa-Bai"; "Kaffernk¾ste", South Africa (False Bay?) (Silva et al. 1996).

Note: Griffithsia cymosa Simons, described from Namibia, is regarded as a synonym of G. confervoides.

Griffithsia confervoides. 1 Habit (female). 2 tetrasporangial stand. 3 Detail of tetrasporangial stand. Reproduced from Stegenga et al. (1997).

Griffithsia confervoides. Fresh specimen, De Hoop.

Griffithsia confervoides. Tetrasporangial stands, stained slide, Goukamma.

Griffithsia confervoides. Apical cells, stained slide, Goukamma.

Order Ceramiales

Family Wrangeliaceae

Griffithsia subbiconica Stegenga 1986: 114, 116, pl. 41

Plants with a creeping proximal part and erect terminal parts up to ca. 2 cm high. Thallus branched dichotomously, as a rule every segment. Plants attached by rhizoids from the acropetal end of the older cells. Cells up to 1500 µm long and 500 µm broad, but up to 1000 µm broad when bearing reproductive structures, the cells somewhat obovate.

Tetrasporangia in several clusters in concentric rings on a subapical cell, the apical cell of the axis similarly inflated. The outer ring of tetrasporangial clusters bearing one or two involucral cells as well on the tetrasporiferous cell. Up to 20 involucral cells may be found in a circle. Tetrasporangia at maturity ca. 75 x 70 µm. Spermatangial clusters profusely branched, ca. 15 clusters on a subapical cell, the apical cell swollen likewise. No involucral cells present in the male structure. Female reproductive structure developing on a subapical cell, the apical cell markedly asymmetric and bending over the developing carposporophyte, the enveloping structure completed by ca. six relatively small two-celled involucral filaments developed from the basal cell of the female fertile filament. Carposporophyte with many relatively small gonimoblasts, the ripe carpospores measuring ca. 35 µm in largest diameter.

Collections, ecology and regional distribution

Not uncommon between Swartklip and East London (18-43), although not as common as G. confervoides. A turf-forming species in shaded localities and in the lower intertidal, also in tidal pools (Stegenga et al. 1997).

World distribution: Type locality: Koppie Alleen, Cape Province, South Africa (Stegenga 1986).

Note: This species is sometimes regarded as synonymous with G. schousboei Montagne (Norris & Molloy, 1988). It has however not been found east of Bat’s Cave (East London), while G. schousboei is supposed to be a tropical and subtropical species.

Griffithsia subbiconica. 1 Habit (female). 2 Tetrasporangial stand. 3 Detail of terasporangial stand. Reproduced from Stegenga et al. (1997).

Griffithsia subbiconica. Tetrasporangial stands, stained slide, Goukamma.

Griffithsia subbiconica. Detail of tetrasporangial stand, stained slide, Goukamma.

Griffithsia subbiconica. Carposporophytes, stained slide, Goukamma.

Griffithsia subbiconica. Detail of carposporophytes, stained slide, Goukamma.

Order Ceramiales

Family Wrangeliaceae

Griffithsia sp.

Plants caespitose, with rhizoids and cross connections between filaments extending high up the thallus, free erect part only up to 1 cm tall. Branching irregular, as a rule the last four or five cells of a branch without laterals. Apical cells flat when cut off, ca. 60 µm in diameter. Cells swiftly increasing in diameter up to ca. 1 mm, almost round to ovate, producing moniliform filaments. Rhizoids produced from the upper end of cells, sometimes making connections with other filaments.

In collected material only carposporophytes present. Procarps formed on the subapical cell, but the axis continues growth even if the carpogonium is fertilized. Female fertile axis three-celled, the basal cell developing five two-celled involucral filaments. Carposporophyte with many gonimolobes, the carpospores at maturity measuring ca. 50 µm.

Apparently closely related to G. subbiconica, but without the asymmetric apical cell connected with the female axis. Also the cells are generally broader and rounder.

Collections, ecology and regional distribution

Only collected at Mbotyi, growing together with Wrangelia purpurifera.

Griffithsia sp. Apical part of thallus, Mbotyi, stained slide.

Griffithsia sp. Carposporophyte, Mbotyi, stained slide.

Order Ceramiales

Family Wrangeliaceae

Gymnothamnion J. Agardh

Thalli with creeping and erect filaments, ecorticate, erect filaments arising from a short cell of creeping axis that also bears an attachment rhizoid. Cells uninucleate, apical cell transversely divided. Branching opposite-distichous. Sporangia single, terminal to subterminal. Three species and one variety are currently recognized (Guiry & Guiry 2015).

Key to species and variety

1a Thalli up to 5-10 mm long, ultimate branchlets up to 20 cells long, sporophyte producing tetrasporangia

Gymnothamnion elegans

1b Thalli up to 2 mm long, Ultimate branchlets to 10 cells long, sporophyte producing bisporangia

Gymnothamnion elegans
var bisporum

Order Ceramiales

Family Wrangeliaceae

Gymnothamnion elegans (Schousboe ex C. Agardh) J. Agardh 1892: 178

Plants clearly differentiated into creeping and erect filaments, the latter up to 5 (-10) mm tall, inserted singly on a short cell of the creeping filament, this cell also producing a multicellular rhizoid. As a rule the short cell of the creeping filament alternates with two (or more) long cells without appendages. Both creeping and erect filaments without cortication, the creeping filaments ca. 25 µm in diameter. Erect filaments with regularly two opposite branches per segment, these all in one plane, often unbranched, sometimes re-branched in the same way, the final ramifications ca. 18 µm in diameter.

Tetrasporangia terminal and (sometimes stalked) subterminal on the final ramifications, measuring ca. 45 x 37 µm, tetrahedrally divided. Male stands in similar positions as tetrasporangia, consisting usually of a basal cell, about three spermatiferous cells and relatively few spermatangia. Female structures not seen on south coast material: according to west coast material “female fertile filaments appearing in the form of little-reduced branchlets of the erect axes, one to several cells bearing procarps” (Stegenga et al. 1997).

Collections, ecology and regional distribution

Recorded from the Cape Peninsula to Mission Rocks/Cape Vidal (16-56), although on the south coast we have not found it east of East London (Bat’s Cave). It is usually found in the upper eulittoral zone, where it grows inside clumps of Bostrychia intricata.

World distribution: Distributed worldwide in tropical to warm temperate areas.

Type locality: Tangiers, Morocco (Silva et al. 1996). 

Gymnothamnion elegans. 1 Microscopic habit. 2 detail with tetrasporangia. 3 Spermatangia. Reproduced from Stegenga et al. (1997).

Gymnothamnion elegans. Creeping axis with erect axes. Stained slide material, Still Bay.

Gymnothamnion elegans.  Tetrasporangial thallus. Stained slide material, Still Bay.

Order Ceramiales

Family Wrangeliaceae

Gymnothamnion elegans var. bisporum Stegenga 1986: 88-90, pl. 30

Differing from the typical variety in reaching only 2 mm in height, the ultimate branchlets being shorter (to 10 cells as opposed to up to 20 cells in the typical variety), the smaller cell diameters (prostrate axes to 20 µm, final branchlets up to 12 µm) and the possession of bisporangia rather than tetrasporangia, measuring at the most ca. 35 x 33,5 µm. The sporangia are usually terminal on the last order branchlets and divided in the longitudinal or more skew direction. There are no sexual organs known from this variety. The earlier mentioned (Stegenga et al. 1997) branching from the prostrate axis every other segment appears to be more varied and branching every third segment is not unusual.

Collections, ecology and regional distribution

Recorded from the Cape Peninsula to East London (16-41). Found at a much deeper level on the shore than the typical variety, even to several meters below low-tide level, usually epiphytic on large seaweeds.

World distribution: So far, it is distinguished as a South African variety only, but it is somewhat rarer than the typical variety.

Type locality: Muizenberg, False Bay, Cape Province, South Africa (Stegenga 1986).

Gymnothamnion elegans var bisporum. Erect axis with bisporangia. Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Wrangeliaceae

Haloplegma duperreyi Montagne 1842: 258, pl. 7: fig. 1

Plants reddish-grey to reddish-brown, erect, flat, complanately branched, lobed to flabellate, a few to 15 cm tall, branches expanding upwards to about 1.5 cm wide distally, margins smooth, irregular, ruffled or lacerate. Holdfast rhizoidal, discoid to conical. Thallus ca 500 µm thick, texture spongy. Structure of branched filaments intermeshed in one plane to form a flat network with short filaments directed towards the thallus surface, imparting a felt-like texture.

Tetrasporangia borne at apices of short branches that are directed towards the surface, cruciately divided, 40-50 µm long. Gametophytes not seen, but reported in Haloplegma to be dioecious, with carposporangia exserted above the blade surface.

Collections, ecology and regional distribution

Recorded from De Hoop area to cape Vidal in KwaZulu-Natal (23-56). Apparently uncommon and subtidal, it has been collected from drift (e.g. at Port Alfred) and by diving (e.g. 6m depth, northern Transkei).

World distribution: in Africa also collected from Kenya, Tanzania and Mauritius, but apparently widespread in tropical and warm temperate seas (records in Guiry & Guiry 2014).

Type locality: Martinique, West Indies (Silva et al. 1996).

Note: see Womersley (1998) for further details of structure.

Haloplegma duperreyi, 6m, Pondoland, northern Transkei. (Herbarium specimen).

Haloplegma duperreyi, 6m, Pondoland, northern Transkei. (Herbarium specimen).

Order Ceramiales

Family Wrangeliaceae

Pleonosporium Nägeli

Plants filamentous, bushy, usually without much development of prostrate parts. Older axes with or without loose rhizoidal cortication. Branching alternate, without a rigid distinction between indeterminate and determinate laterals; branches distichous or polystichous. Asexual reproduction by means of polysporangia; spermatangial heads cylindrical or cylindro-conical. Carposporophytes with globose gonimolobes and surrounded by varying numbers of involucral filaments. Worldwide, 30 species are currently recognized (Guiry & Guiry 2015).

Note: The widespread species formerly known as Pleonosporium caribaeum (Rosenvinge) R.E. Norris, was transferred to Spongoclonium by Wynne (2005) because it possesses tetrasporangia (sometimes octosporangia) rather than polysporangia. The same character means that Pleonosporium callicladum R.E. Norris should also be transferred to Spongoclonium, but this has not been formally done, so we have left it in the genus Pleonosporium.

Key to species

1a. Sporophyte with tetrasporangia

Pleonosporium callicladum

1b. Sporophyte with polysporangia

2

2a. Ultimate branchlets long and unbranched (apart from reproductive structures)

Pleonosporium harveyanum

2b. Ultimate branches ramified right to the top

Pleonosporium filicinum

Order Ceramiales

Family Wrangeliaceae

Pleonosporium callicladum R.E. Norris 1985: 63, figs 8-28

Plants, as found, under 1 cm in length, basally attached with a number of multicellular rhizoids. Erect axes with laterals alternating in one plane, re-branched often twice, somewhat shorter than the main axis. Axes without cortication, up to 150 µm in diameter, the cells in older part slightly shorter than broad, in younger parts slightly longer than broad. Apical cells 12.5-15 µm in diameter.

Tetrasporangia single or with two together on cells of the upper regions of the laterals, sessile, measuring ca. 48 x 37 µm at maturity, division tetrahedral. Male plants not seen. Female fertile filament developing in apical position on the side branches, the developing carposporophyte becoming surrounded by up to four re-branched ramuli from the sterile cell below it. Mature carposporophytes not seen.

Collections, ecology and regional distribution

Recorded from Stilbaaai to the Port Shepstone area of KwaZulu-Natal (26-49). Apparently an uncommon species, mainly found in the sublittoral (down to at least 23 m), growing on other plants or animals. The species was described from KwaZulu-Natal (Norris, 1985).

World distribution: South African endemic.

Type locality: Palm Beach, near Port Edward, KwaZulu-Natal, South Africa (Silva et al. 1996).

Note: because this species has tetrasporangia rather than polysporangia, it should be transferred to Spongoclonium, as was done for P. caribaeum (Rosenvinge) R.E. Norris – see Wynne (2005). 

Pleonosporium callicladum, sterile thallus apex. (Morris Point, Stilbaai, 11m, on Zonaria sp; stained slide).

Pleonosporium callicladum, thallus apex with carposporophyte. (Morris Point, Stilbaai, 23m, on Heringia mirabilis; stained slide).

Pleonosporium callicladum, tetrasporangia (see note); stained slide.

Order Ceramiales

Family Wrangeliaceae

Pleonosporium filicinum (Harvey ex J. Agardh) De Toni 1903: 1308

Plants up to 5 (-20) cm tall. Thallus complanate, with a distinct main axis, branched every segment. Branching to the fifth order, axes of all orders strongly flexuose. Main axes up to 350 µm in diameter, the cells up to 1.3 mm long, ecorticate. Terminal cells ca. 55 µm in diameter. Branches are as a rule single, but opposite branches may occur in some older laterals on basal segments.

Polysporangia sessile, usually on the basal cells on several orders of laterals, measuring ca. 125 x 100 µm, containing ca. 32 to 64 spores. Spermatangial heads in terminal position on the branchlets, sometimes becoming subterminal as the bearing cell produces another branchlet. Spermatangial heads short cylindrical, with a four-celled axis (hardly visible in mature heads), measuring ca. 100 x 50 µm. Female fertile filament three-celled, developing in an apical position, the hypogenous cell almost at the same time developing a single involucral filament that branches repeatedly. Full-grown carposporophytes nearly round, ca. 350 µm in diameter, with two or three gonimolobes visible. Carpospores at maturity ca. 50 µm in diameter. In cases where the carpogonium is not fertilized, the hypogenous cell develops a normal vegetative branch and the fertile filament becomes subapical.

Collections, ecology and regional distribution

Recorded from Swartklip (False Bay) to the Durban Area of KwaZulu-Natal (18-51). Found along the whole south coast, not rare; occurring on lifeless substrata or on calcareous algae.

World distribution: Southern African endemic, also found in Namibia (Rull Luch 2002).

Type locality: Muizenberg, Western Cape Province, South Africa (Silva et al. 1996).

Note: A related species, P. paternoster Stegenga, differs mainly by its smaller polysporangia and the possession of six involucral branches around the carposporophytes – it is so far found only in the South-West Cape (Stegenga et al. 1997).

Pleonosporium filicinum. 1 Thallus apex with polysporangia. 2 polysporangia. Reproduced from Stegenga et al. (1997).

Pleonosporium filicinum, thallus apex with polysporangia (stained slide).

Pleonosporium filicinum, polysporangia (stained slide).

Pleonosporium filicinum, carposporophyte (stained slide).

Pleonosporium filicinum, female fertile filament (stained slide).

Pleonosporium filicinum, spermatangial stands (stained slide).

Order Ceramiales

Family Wrangeliaceae

Pleonosporium harveyanum (J. Agardh) De Toni 1903: 1309

Plants up to 5 cm tall, bushy, with several erect axes; older axes with a loose rhizoidal cortication. Branching alternate, in the apical sections of the plant generally complanate. The ultimate branchlets (apart from reproductive organs) long and unbranched, near the apices strongly incurved. Main axes up to 200 µm broad (without cortication), ultimate cells 15 µm broad, the cells 2-3 times longer than broad.

Polysporangia sessile on a row of basal cells of the laterals, almost round, measuring ca. 110 µm in diameter, producing ca. 32-64 spores. Spermatangial stands adaxial on a number of cells of the ultimate branchlets, cylindrical with a ca. six-celled central axis, measuring ca. 140 x 50 µm at maturity.Female structures not seen in south coast material, for a description see Stegenga (1986).

Collections, ecology and regional distribution

Recorded along the whole west coast (Stegenga et al. 1997) and south coasts, to Port Shepstone in KwaZulu-Natal (1-49). Epilithic, occasionally on other algae or Pyura. Although primarily a West Coast species, it is not rare on the south coast, but it seldom grows longer than 2 cm.

World distribution: southern African endemic, also recorded from Namibia (Rull Lluch 2002) and Mozambique (Silva et al. 1996).

Type locality: Cape of Good Hope, South Africa (Silva et al. 1996).

Pleonosporium harveyanum. Detail of thallus with polysporangia. Reproduced from Stegenga et al. (1997).

Pleonosporium harveyanum. Thallus apex with polysporangia (Haga Haga, stained slide).

Pleonosporium harveyanum. Detail of polysporangia (Haga Haga, stained slide).

Pleonosporium harveyanum. Spermatangial stands (Haga Haga, stained slide).

Order Ceramiales

Family Wrangeliaceae

Shepleya elixithamnia Gordon-Mills & R.E. Norris 1986: 160-166, figs. 1-15, table 1

Plants soft and delicate, red, up to about 4 cm long, ecorticate, largely prostrate, only the thallus apices free for some distance. Axes usually with two opposite branches per cell arising subapically, and one or two unicellular haptera arising somewhat above a proximal position. Branches are usually re-branched once or may develop to the same complexity as the main axes. Apical cells ca. 100 µm in diameter in the main axes, ca. 75 µm in the side branches. Main axial cells up to 500 µm long and 200 µm broad, without cortication. Tetrasporangia ca. 150 µm in diameter, sessile on cells of somewhat richer-branched laterals. Other reproductive structures not seen (but see De Clerck et al. 2005).

Collections, ecology and regional disrtibution

Our own collections are only from Mkambathi and Mzamba in eastern Transkei. This species is reported (De Clerck et al. 2005) to be otherwise limited to southern KwaZulu-Natal. Gordon-Mills and Norris (1986) report its distribution as “the Indian Ocean coast of South Africa from northern Natal to near East London”, but the most southern and northern records indicate a range from Mkambathi to Mvoti river in KZN (47-52) . Locally it is not rare, and is found as an epiphyte on various articulated calcified algae (e.g. Amphiroa bowerbankii, Halimeda cuneata).

World distribution: South African endemic.

Type locality: Palm Beach, near Port Edward, KwaZulu-Natal, South Africa. (Silva et al. 1996).

Shepleya elixithamnia, growing on Amphiroa bowerbankii (Photo O. De Clerck).

Shepleya elixithamnia, thallus apex. Arrow shows young attachment structure. Mkambathi, stained slide.

Shepleya elixithamnia, thallus apex. Mkambathi, stained slide.

Shepleya elixithamnia, tetrasporangia. Mkambathi, stained slide.

Order Ceramiales

Family Wrangeliaceae

Spermothamnieae indet.

Plants forming a dense velvety cover on the host, consisting of prostrate filaments and erect filaments ca. 2(-2.5) mm tall. Prostrate filaments attached by one or sometimes two unicellular digitate haptera per cell. Erect filaments and haptera arise in about the middle of the cells of the creeping filament. Erect filaments virtually unbranched, sometimes with a few laterals. Erect filaments straight, ca. 25 µm broad, the cells 3-4 times as long as broad. Male stands single at the top of the erect filaments, as a rule with a four-celled axis, measuring ca. 75 x 35 µm. Other reproductive structures not seen.

Generic affinity uncertain as only male reproductive structures were found. There seems to be a good overlap in cell dimensions and general morphology (especially the strictly terminal placement of reproductive structures on virtually unbranched erect axes) with Spermothamnieae indet. in Stegenga (1988).

Collections, ecology and regional distribution

Collected at Morgan Bay, on an Ecklonia radiata stipe, but if the same as Spermothamniae indet. (Stegenga 1988), then also from Port Alfred (on Pyura) indicating a range of at least 39-43).

Note: For further details of the Port Alfred material and its possible taxonomy, see Stegenga (1988). The tribe Spermothamniae is currently placed within the family Wrangeliaceae.

Spermothamnieae indet. Erect filaments with terminal male structures. Stained slide material, Morgan Bay.

Spermothamnieae indet. Erect filaments, prostrate filaments and attachment structures. Stained slide material, Morgan Bay.

Spermothamnieae indet. Terminal male structures. Stained slide material, Morgan Bay.

Order Ceramiales

Family Wrangeliaceae

Spongoclonium caribaeum (Børgesen) M.J.Wynne 2005: 23, 87

Plants up to a few cm tall, attached basally by a number of rhizoidal filaments. Main axes up to 150 (-200) µm in diameter, in the lower regions surrounded by a loose cortex of rhizoidal filaments. One lateral per segment, these formed multilaterally or in part bilaterally, as a rule re-branched once, young laterals somewhat incurved. Apical cells ca. 12 µm in diameter.

Tetrasporangia (occasionally octosporangia) in series, sessile on the ultimate branchlets, one sporangium per cell, measuring ca. 55 x 50 µm, tetrahedrally divided. Male stands cylindro-conical, in similar positions as the tetrasporangia, with a ca. five-celled central axis, measuring ca. 75 x 30 µm. Carposporophytes with a number of gonimolobes of different ages; the largest up to 400 µm in diameter; virtually all cells developing into carpospores, ca 25 µm in diameter.

Collections, ecology and regional distribution

Recorded from False Bay to northern KwaZulu-Natal (17-58). Noted by Stegenga et al. (1997) as fairly common in the Eastern Cape. Epilithic and epiphytic in the sublittoral fringe to at least 30 m depth (De Clerck et al. 2005).

World distribution: almost world-wide in warm temperate to tropical areas (references in Guiry & Guiry 2015).

Type locality: Annaberg, St. John, Virgin Islands (Silva et al. 1996).

Note: Earlier known as Pleonosporium caribaeum (Rosenvinge) R.E. Norris, it was moved to Spongoclonium by Wynne (2005) because it possesses tetrasporangia (sometimes octosporangia) rather than polysporangia. The same would apply to Pleonosporium callicladum R.E. Norris although that species has not formally been transferred to Spongoclonium.

Spongoclonium caribaeum. Photographed in KwaZulu-Natal (O. De Clerck).

Spongoclonium caribaeum, reproductive structures. 1 Tetrasporangia. 2 Stages in development of procarp. 3, 4 Development of spermatangial stands. Reproduced from Stegenga et al. (1997), as Pleonosporium caribaeum.

Spongoclonium caribaeum, thallus apex with young tetrasporangia. Stained slide material, Goukamma oyster beds.

Spongoclonium caribaeum, spermatangial stands. Stained slide material, Goukamma oyster beds.

Spongoclonium caribaeum, tetrasporangia. Stained slide material, Goukamma oyster beds.

Order Ceramiales

Family Wrangeliaceae

Stegengaea capensis (Stegenga) Alongi, Cormaci & G.Furnari 2007: 319

Plants minuscule, forming a cover on the utricles of Codium spp. Plants built up of a system of creeping filaments and many short erect filaments. Creeping filaments consisting of irregular cells, up to 175 µm long and 15-25 µm broad, often with a downward blunt process but without true haptera. Each cell of the prostrate system with one to a few erect axes, these unbranched or with a few laterals in the proximal part. Erect axes up to 400 µm high, ca. 25 µm broad in the proximal part, hardly tapering in the distal part, the cells little longer than broad, the basal cell usually longer.

Polysporangia single on top of short erect axes, ca. 50 X 45 µm, usually producing 16-20 spores. Spermatangia terminal on erect axes, several spermatangium mother cells occurring on the terminal cell in an umbellate construction, each cell with one spermatangium. Female fertile filaments four-celled, sessile on the creeping filament. The subapical cell with only a supporting cell bearing a sterile cell and a four-celled carpogonial filament. Carposporophyte with small gonimolobes and terminal carposporangia ca. 25 X 20 µm.

Collections, ecology and regional distribution

Found once at Haga Haga, otherwise a West Coast species (1-43). Endophytic in Codium, growing between and on the utricles.

World distribution: South African endemic (Stegenga et al. 1997, as Lomathamnion capensis).

Type locality: Buffels Bay, (Western) Cape Province, South Africa (Silva et al. 1996).

Note: formerly known as Lomathamnion capense Stegenga (see Stegenga 1984).

Stegengaea capensis, . 1 Microscopic habit, male plant with spermatangial heads. 2 Female plant with numerous procarps. 3-4 Polysporangia. 5 Carposporophyte. Reproduced from Stegenga et al. (1997), as Lomathamnion capense.

Stegengaea capensis, microscopic habit. Stained slide, Haga Haga material.

Stegengaea capensis, polysporangia. Stained slide, Haga Haga material.

Stegengaea capensis, procarps. Stained slide, Haga Haga material.

Order Ceramiales

Family Wrangeliaceae

Tiffaniella Doty & Meñez

Plants differentiated into prostrate and erect filaments, ecorticate, attached by unicellular haptera. The genus differs from others in the tribe Spermothamniae in having the carposporophytes developing from two auxiliary cells, with a central fusion cell and not surrounded by involucral filaments. Twelve species are recognized worldwide (Guiry & Guiry 2015), of which two occur on the south coast.

Key to the species

1a. Tetrasporangia in up to 4 or 5 clusters per cell of the erect axes; female fertile filament consisting of four short cells

Tiffaniella cymodoceae

1b. Tetrasporangia in 1 (2) clusters per cell of the erect axes; female fertile filament consisting of three short cells

Tiffaniella schmitziana

Order Ceramiales

Family Wrangeliaceae

Tiffaniella cymodoceae (Børgesen) E.M.Gordon 1972: 121-123, figs. 39D-F, 40

Plants epiphytic on Codium spp., differentiated into creeping filaments, unicellular haptera and erect filaments up to 5 mm tall. Cells of the creeping filaments ca. 37 µm in diameter, about 4 or 5 times longer than broad, with one (or two) haptera on the proximal end and an erect filament on the distal end. Erect filaments ca. 37 µm in diameter basally, slightly tapering to the apex to about 30 µm, long-celled as the prostrate filaments are. Erect axes sparsely branched, reproductive laterals often more abundant.

Tetrasporangia arranged in up to four or five small cymose clusters on the proximal cells of the erect axes, measuring ca. 45 x 40 µm, tetrahedrally divided. Spermatangia in cylindrical to conical heads, with four- to five-celled axes, occurring on a number of subapical cells of the erect axes, measuring ca. 75 x 37 µm. Female fertile filament four-celled, often terminal on a one- or two-celled lateral. The subapical cell with one sterile cell and two fertile cells. Mature carposporophyte with a prominent central T-shaped cell consisting of the fused second and third cell of the fertile filament with the auxiliary cells (and proximal gonimolobe cells). Carposporophytes may grow to about 250 µm in diameter. Only the terminal cells of the gonimolobes ripen to carpospores measuring ca. 30 X 22 µm. There are no involucral filaments, but often the cell below the subhypogenous cell emits two or three filaments that continue growth after fertilization.

Collections, ecology and regional distribution

During the present study only found from Bird Island (Algoa Bay) eastward, but Stegenga et al. (1997) mentioned it from False Bay (17-58). It is reported to occur as far east as Mozambique. The type of T. cymodoceae is however described from the sea grass Cymodocea (from Mauritius), whereas all our material was found on Codium spp.

World distribution: Mauritius (type locality), Mozambique, and South and Western Australia, in the last locality also on Codium spp. (Womersley 1998).

Type locality: Riambel, near Souillac, Mauritius (Silva et al. 1996).

Tiffaniella cymodoceae. 1. Habit, tetrasporangial. 2 Tetrasporangia. 3. Spermatangial heads. 4. Carposporophyte. Reproduced from Stegenga et al. (1997).

Tiffaniella cymodoceae. Microcopic habit, with tetrasporangia. Stained slide, Mntafufu (east of Port St Johns, Transkei).

Tiffaniella cymodoceae. Detail of creeping filament with attachment structures and erect axes with tetrasporangia. Stained slide, Mntafufu.

Tiffaniella cymodoceae. Male reproductive thallus. Stained slide, Mntafufu.

Tiffaniella cymodoceae. Detail of male reproductive thallus. Stained slide, Mntafufu.

Order Ceramiales

Family Wrangeliaceae

Tiffaniella schmitziana (Barton) Bolton et Stegenga 1987: 177, figs. 6d,e

Plants creeping on the surface of sturdy algae (Zonaria spp., Gelidium abbottiorum, Corallines), the creeping filaments giving off a hapteron on the proximal ventral side of the cells, an erect filament on the distal dorsal side. Cells of the creeping filaments ca. 30 μm in diameter, about 4 times as long as broad. Erect filaments up to a few mm tall, irregularly and often not frequently branched, although on the apices a uniseriate row of laterals may be present. Erect filaments somewhat variable in diameter, from ca. 25 μm near the base to ca. 50 μm in the middle, filaments not tapering much towards the apices. Cell length in the erect filaments varying from 3 to 7 times the diameter.

Tetrasporangia in small cymose clusters on the basal areas of the erect filaments, usually not more than one (two) clusters per cell. Tetrasporangia measuring up to ca. 70 x 55 μm, tetrahedrally divided. Spermatangia in a unilateral row of sessile cylindrical clusters on subterminal cells. Spermatangial clusters with a four- to five-celled axis, measuring ca. 100 x 45 μm. Female fertile filament three-celled, terminal on a one- or two-celled lateral, the subterminal cell with one sterile pericentral cell and two fertile pericentrals. Carposporophytes with a large deltoid fusion cell consisting of the two proximal cells of the fertile filament, the auxiliary cells and proximal gonimoblast cells. Only the terminal cells of the gonimoblasts develop into carposporangia, measuring ca. 50 x 42 μm. The complete carposporophyte may measure ca. 250 μm in diameter.

Collections, ecology and regional distribution

Recorded from Kraalbaai in Langebaan Lagoon (west coast) to at least the Eastern Cape – KwaZulu-Natal border (18-47) but probably occurs further north. Stegenga et al. (1997) report it as epilithic but more usually epiphytic. 

World distribution: South African endemic.

Type locality: “Cape of Good Hope”, South Africa (Silva et al. 1996).

Tiffaniella schmitziana. 1 Apex of prostrate filament with young erect axes. 2 Apex of erect axis. 3 Procarp. 4 Tetrasporangia. Reproduced from Stegenga et al. (1997).

Tiffaniella schmitziana.  Microscopic habit with carposporophytes. Stained slide, Goukamma oyster beds.

Tiffaniella schmitziana. Carposporophytes : note deltoid fusion cell. Stained slide, Goukamma oyster beds.

Tiffaniella schmitziana. Male thallus. Stained slide, Goukamma oyster beds.

Order Ceramiales

Family Wrangeliaceae

Vickersia baccata (J. Agardh) Karsakoff 1896: 285

Plants largely creeping, the apices for about 1-3 mm ascending. Main axis attached by unicellular rhizoids originating from about the middle of the cell, sometimes provided with a digitate hapteron. Main axial cells up to 350 μm long and 100 μm broad, much shorter at the apex and about 15-20 μm broad. Indeterminate laterals arising at intervals of two to several segments. Segments provided with (1-)2(-3) determinate laterals, usually two cells long, but one- and three-celled branches also occur. Branchlets with a cylindrical basal cell but commonly with a much inflated top cell, measuring up to 300 μm long and 200 μm broad. Branchlets on consecutive axial cells roughly decussate.

Sporangia found as the only reproductive structures, a single tetrasporangium sessile on the basal cell of a determinate branchlet, about round and measuring ca. 70 μm in diameter. Occasional octosporangia occur, slightly larger than the tetrasporangia.

Collections, ecology and regional distribution

The only records of this species in South Africa are from Tsitsikamma (subtidal, see Stegenga et al. 2000) and from Leven Point (near Cape Vidal in KwaZulu-Natal, at 11m, on ascidians) (32-56). It appears to be rare, and only found below the low tide level.

World distribution: Its distribution is mainly in the Mediterranean and adjacent North Africa and a number of Atlantic Islands.

Type locality: Azores (Athanasiadis 1996).

Vickersia baccata, Leven Point, KwaZulu-Natal. Stained slide.

Vickersia baccata, Leven Point, KwaZulu-Natal. Stained slide.

Vickersia baccata, with tetrasporangia. Leven Point, KwaZulu-Natal. Stained slide.

Order Ceramiales

Family Wrangeliaceae

Wrangelia purpurifera (Harvey) J. Agardh 1863: 707

Plants up to several cm tall, the basal region attached by several rhizoids originating from the basal cells of the whorl branches. Main axes prominent, the cells measuring up to 800 µm in length and 250 µm in diameter, each provided with 4 or 5 whorl branches; on the lower reaches the axes may be incompletely and loosely corticated by multicellular rhizoids. Indeterminate laterals not present in all whorls, although sometimes rather frequent. Determinate branchlets within one whorl of various development, the simplest consisting of just a single row of cells, the more intricate branchlets several times (sub)dichotomously branched. Apical cells of the whorl branchlets tapered to a sharp apex. Whorl branchlets up to 1.5 mm long

Tetrasporangia in branched clusters on the cells of main axes and indeterminate laterals, the vegetative branchlets in that case reduced in number. Tetrasporangia round, measuring ca. 75 µm in diameter, tetrahedrally divided and surrounded by short incurved filaments. Male stands round, ca. 75 µm in diameter, in repeatedly branched systems directly on main axes and laterals of indeterminate growth, replacing ordinary laterals; the male clusters surrounded by a few two- or three-celled involucral filaments. Carposporophytes seemingly terminal on indeterminate branches, up to 0.5 mm in diameter, surrounded by incurved branchlets from the segments below. Carpospores terminal on the gonimoblasts, teardrop-shaped, measuring ca. 90 x 40 μm.

Collections, ecology and regional distribution

Recorded along the West coast and to Mbotyi (1-47). It is often found in the (lower) intertidal and rarely grows on other plants. Stegenga et al. (1997) note that it is a species of spring and early summer.

World distribution: South African endemic.

Type locality: Cape of Good Hope, South Africa (Silva et al. 1996).

Wrangelia purpurifera. 1 Part of main axis with whorled branchlets. 2 Tetrasporangiferous branch systems. Reproduced from Stegenga et al. (1997).

Wrangelia purpurifera. Thallus apex. Stilbaai, stained slide.

Wrangelia purpurifera. Tetrasporangia. Mbotyi, stained slide.

Wrangelia purpurifera. Carposporophyte. Stilbaai, stained slide.

Wrangelia purpurifera. Male thallus. Kei Mouth, stained slide.

Order Corallinales

Family Corallinaceae

Sub-family Corallinoideae

Amphiroa J.V. Lamouroux

Thalli with a crustose base and dichotomously branched cylindrical or compressed upright axes. Conceptacles distributed over most of the surface of the intergenicula, often several to many per segment. Intergenicula with wings in some species. There are 49 species currently recognized worldwide, and the genus is common in tropical and subtropical regions (Guiry & Guiry 2014). Six species are recorded from the South African south coast. Four of these were included in a recent DNA barcoding study of South African geniculate corallines (Kogame et al. 2017).

Key to south coast Amphiroa

1 a. Genicula very distinct, blackish-purple, 1-2 mm long in older parts of thallus

A. ephedraea

1 b. Genicula less than 1 mm long in older parts of thallus, indistinct or invisible

2

2 a. Axes flattened, genicula bearing distinct, pinkish, calcified nodules

A. bowerbankii

2 b. Axes cylindrical or flattened, no calcified nodules on genicula

3

3 a. Genicula hidden by aprons at upper and lower ends of intergenicula, axes cylindrical

A. capensis

3 b. Genicula not hidden by aprons, axes cylindrical or flattened

4

4 a. Axes flattened, intergenicula 3-10 (-15) mm long, 0.5-3 (-4) mm wide

A. anceps

4 b. Axes cylindrical to slightly compressed, intergenicula no longer than 5 mm

5

5 a. Axes cylindrical to slightly compressed, intergenicula 0.5-1 mm wide, genicula visible but inconspicuous

A. beauvoisii

5 b. Axes cylindrical, plants fine, intergenicula less than about 0.5 mm diameter, genicula barely visible or invisible

A. rigida

Order Corallinales

Family Corallinaceae

Sub-family Corallinoideae

Amphiroa anceps (Lamarck) Decaisne 1842: 125

Plants up to 7 (-10) cm tall, forming loose tufts, pink to grayish, with crustose holdfast bearing erect axes. Axes complanate, branching dichotomous to sometimes trichotomous. Genicula purple-black, fairly conspicuous but partly obscured by edges of intergenicula above, so that they are seldom visible as bands, but rather as dark oblongs. Intergenicula flattened, elongated rectangular, of fairly uniform width but very variable in size, 3-10 (-15) mm long and 0.5 – 3 (-4) mm wide, almost cylindrical basally becoming flattened distally, with sharp margins, apices of terminal segments often pale to white. Surfaces of axes smooth or with finely warty texture when fertile (then usually on one side of intergenicula). Branching from distal ends of most intergenicula, seldom from margins: distal shoulders of intergenicula seldom extending beyond genicula.

Collections, ecology and regional distribution

Growing on rock from lower eulittoral (often hanging on sides of gulleys) to at least 30 m depth. Found from Stilbaai to northern KwaZulu-Natal (26-58).

World distribution: Recorded from tropical and warm temperate localities in western Pacific, Indian Ocean, western Atlantic and Australia (Guiry & Guiry 2014).

Type locality: Norfolk Island, Pacific.

Note: In the DNA barcoding study of Kogame et al. (2017), the three South African specimens identified morphologically as A. anceps formed a clear clade. 

Amphiroa anceps, De Hoop.

Amphiroa anceps, detail of shape.

Order Corallinales

Family Corallinaceae

Sub-family Corallinoideae

Amphiroa beauvoisii  Lamouroux 1816: 299-300

Plants up to 10 cm tall, forming firm often dense tufts, pale pink, grayish or violet, with crustose holdfast bearing several axes. Axes complanate, branching regularly dichotomous to sometimes polychotomous. Genicula purple-black, fairly conspicuous, usually flanked by calcified shoulders of intergenicula above and below. Intergenicula cylindrical proximally to slightly compressed distally, 1-5 mm long and 0.5 to 1 mm in diameter; broadening where branches subtended, sometimes asymmetrical in shape; lateral branching from asymmetric distal portions of intergenicula common, branching every 1-3 intergenicula; terminal segments usually flattened, sometimes forked at ends. Reproductive structures in hemispherical conceptacles (about 300 µm diameter), borne on surfaces of mostly older intergenicula, inconspicuous but visible.

Collections, ecology and regional distribution

Epilithic in rock pools and from eulittoral fringe to at least 20 m depth. Found from Glencairn, False Bay, to tropical East Africa (17-58). This species is uncommon west of Cape Agulhas but common on the south and east coasts.

World distribution: Widespread in tropical and temperate seas.

Type locality: Portugal (Silva et al. 1996).

Note: A DNA barcoding study of South African articulated corallines (Kogame et al., 2017) showed that more than one species may fit the description of A. beauvoisii, indicating the need for further studies.

Amphiroa beauvoisii.

Amphiroa beauvoisii, note genicula.

Amphiroa beauvoisii, detail.

Amphiroa beauvoisii. Fertile thallus. Reproduced from Stegenga et al. (1997).

Order Corallinales

Family Corallinaceae

Sub-family Corallinoideae

Amphiroa bowerbankii Harvey 1849: 97, pl. 37 figs 1-6.

Plants up to 14 cm tall, pink to grayish-pink, forming dense, bushy tufts of broad, flat axes arising from crustose holdfast; axes flat with sharp edges, complanate, dichotomously to sometimes tri-or tetrachotomoulsy-branched. Genicula purplish, distinct, bearing small but conspicuous pink, calcified nodules; intergenicula flattened, rectangular, 5-8 mm long, 2-4 mm wide, apical segments with sharp, pale-white distal margins; branching at distal ends of almost all intergenicula and seldom from margins; shoulders of intergenicula sometimes extending beyond genicula. Reproductive structures in warty conceptacles on surfaces of intergenicula.

Collections, ecology and regional distribution

Epilithic in rock pools and from the lower eulittoral down to at least 28 m depth (De Clerck et al. 2005). Found from Stilbaai along the south and east coasts to Mabibi in northern KZN (26-57).

World distribution: Reported from Madagascar, Sri Lanka and Indonesia (Silva et al. 1996).

Type locality: Algoa Bay, Eastern Cape, South Africa (Guiry & Guiry 2014).

Note: Although Millar (1990) considered A. bowerbankii to be a synonym of A. anceps, De Clerck et al. (2005) noted that South African specimens of A. bowerbankii are broader than A. anceps and that the genicula of A. bowerbankii bear “prominent calcified nodules”. These differences are supported by the DNA barcoding study of Kogame et al. (2017), showing clear separation of these entities.

Amphiroa bowerbankii, Haga Haga.

Amphiroa bowerbankii, note calcified nodules on genicula.

Order Corallinales

Family Corallinaceae

Sub-family Corallinoideae

Amphiroa capensis Areschoug in J. Agardh 1852: 533

Plants grayish, up to 10 (-15) cm tall, regularly dichotomously (rarely trichotomously) branched. Genicula inconspicuous, only exposed in older parts of plant. Intergenicula cylindrical, up to 12 mm long, 1-2 mm in diameter, with distinct aprons at upper and particularly lower ends that obscure the genicula. Conceptacles up to 600 µm in diameter, hemispherical, imparting warty appearance to fertile segments.

Collections, ecology and regional distribution

Occurs in deep rock pools and from the subtidal fringe to subtidal zone. Found from the western Cape Peninsula to Port Alfred (16-39)

World distribution: This is considered to be a South African endemic and a record from West Africa is discounted by Lawson and John (1982).

Note: this was not among the South African species examined in the barcoding study of Kogame et al. (2017).

Amphiroa capensis, Arniston.

Amphiroa capensis. Reproduced from Stegenga et al. (1997).

Order Corallinales

Family Corallinaceae

Sub-family Corallinoideae

Amphiroa ephedraea (Lamarck) Decaisne 1842: 124

Plants pink to grayish-pink, forming large bushes up to 30 cm tall attached by crustose holdfast. Genicula very prominent, up to 2 mm long, visible as purple to black bands. Intergenicula cylindrical to slightly flattened, fairly uniform in width, up to 7 mm long and 0.5 – 2 (-3) mm in diameter. Branching regular, dichotomous to (rarely) trichotomous from ends of intergenicula or sometimes from margins. Reproductive structures in hemispherical conceptacles (about 0.5 mm diameter) on surfaces of intergenicula, imparting warty appearance.

Collections, ecology and regional distribution

Common and often abundant on the south coast. Occurs from Cape Hangklip to Mozambique (De Clerck et al. 2005) (19-58). Epilithic from subtidal fringe to at least 34 m depth, also in rock pools where there is much water movement.

World distribution: Also recorded from Madagascar, Tanzania, and several tropical Indo-Pacific locations (Guiry & Guiry 2014) as well as Gambia in West Africa (Price, John and Lawson 1986).

Type locality: Australia: “les mers Australes ou de la Nouv. Holl.” (Silva et al. 1996).

Notes: 1. Details of the reproductive structure are described by Johansen (1986).

2. This was among the South African species examined in the DNA barcoding study of Kogame et al. (2017), and formed a distinct clade.

Amphiroa ephedraea, Qologha.

Amphiroa ephedraea, showing distinct genicula.

Amphiroa ephedraea. Reproduced from Stegenga et al. (1997).

Order Corallinales

Family Corallinaceae

Sub-family Corallinoideae

Amphiroa rigida J.V. Lamouroux 1816: 297, pl. XI: fig. 1

Plants pink to grayish, 2-3 (-5) cm tall, terete, dichotomously branched, somewhat delicate. Genicula barely visible or invisible to naked eye. Intergenicula 2-4 mm long and about 0.5 mm diameter, cylindrical but slightly flattened at tips. Conceptacles 200-300 µm in diameter. Branching in some specimens at fairly wide angle (40-50o).

Collections, ecology and regional distribution

From Walker Point (Buffalo Bay) to at least Black Rock in northern KZN (29-58).

World distribution: Also recorded from Tanzania (Oliveira et al. 2005) and Mauritius (Silva et al. 1996) and widely distributed in temperate and tropical waters (Guiry & Guiry 2014).

Type locality: Meditterranean Sea (Silva et al. 1996).

Note: this seldom-collected species may be rare or overlooked on account of its small size and tendency to occur in turfs. On the south coast it is only recorded from Walker Point, Kowie Estuary, and Mzamba. We have not seen “some anastomoses between contacting branches” that Oliveira et al. (2005) noted in Tanzanian material. This taxon was not among the South African species examined in the barcoding study of Kogame et al. (2017), and requires further study.

Amphiroa rigida, Palm Beach, KZN (BOL). Scale on left in mm. A tiny Jania sp. is visible in the middle of the Amphiroa thallus.

Amphiroa rigida, Palm Beach, KZN (BOL). Detail showing wart-like conceptacles on many segments.

Amphiroa rigida, typical tangled turf specimens, Tsitsikamma (BOL). Scale on left in mm.

Order Corallinales

Family Corallinaceae

Sub-Family Corallinoideae

Arthrocardia Decaisne

Thalli of crustose holdfasts bearing erect, articulated, branched fronds; branching dichotomous in fertile parts, pinnate in vegetative parts. Fronds comprising calcified intergenicula (segments) separated by uncalcified genicula. Conceptacles terminal and axial in fertile segments.

Johansen (1984) stated that “Arthrocardia, represented by four species in South Africa, is characterized by Corallina-like pinnate branching in the vegetative axes and a propensity for regularly producing branches on the fertile intergenicula of all reproductive types.” Later, Seagrief (1984) listed 6 species in South Africa.

Recently, a DNA barcoding study by Kogame et al. (2017) recorded 7 distinct clades of Arthrocardia among 63 articulated coralline specimens (all genera) collected along the South African coast. This study, which aimed to “test the morphological classification” of species within the genera, identified seven (species-level) clades of Arthrocardia. All of the five recorded south coast species except A. palmata were identified. However, A. palmata may have been represented by a specimen from Palm Beach in southern KwaZulu-Natal, in a clade called Arthocardia sp. 1.

While many specimens fit the descriptions of the species below, there are also some that do not, or appear intermediate between certain of these species. It is clear that further molecular and morphological studies would be useful.

Key to south coast Arthrocardia

1a. Branching mostly pinnate

2

1b. Branching mostly dichotomous, at least in upper parts

3

2a. Upper segments 3-4 (-6) mm long, often winged, and/or with long (-6 mm), awl-shaped branchlets

A. duthieae

2b. Upper segments 1-.5 – 3 mm long, wedge-shaped, without long branchlets

A. carinata

3a. Branching dichotomous in fertile areas above, irregularly pinnate below; ultimate segments often incised (branched without articulations); males with beaked conceptacles

A. flabellata

3b. Branching mainly dichotomous throughout; incised end-segments absent; male conceptacles not beaked

4

4a. Adventitious branching present, sometimes from all sides of segments

A. palmata

4b. Adventitious branching absent/rare

A. corymbosa

Order Corallinales

Family Corallinaceae

Sub-Family Corallinoideae

Arthrocardia carinata (Kützing) Johansen 1984: 2, 5

Plants pink to chalky pink, bushy, up to 8 cm tall, erect axes complanate, holdfast crustose; erect axes pinnately branched, branching more frequent distally, branches arising from axils or tips of lobes of segments, lobe angle 20-30o, adventitious branching rare. Genicula inconspicuous. Intergenicula in proximal parts of plants terete to subterete, 0.5-1.0 mm diameter, in distal parts flattened, often wedge-shaped, 1.5 – 3.0 mm long, 0.5- 5 mm wide distally (but see note). Conceptacles rarely seen, axial, terminal, with single terminal ostiole; in terminal branchlets.

Collections, ecology and regional distribution

Epilithic, recorded from tide pools to 28m depth. Common along south and east coasts of South Africa from Stilbaai to Cape Vidal (26-56). Recorded in Namibia (Rull Lluch 2002), but not from SA west coast.

World distribution: Also found at St Helena and in Mozambique (Guiry & Guiry 2014).

Note: In a recent DNA barcoding study, Kogame et al. (2017) reported an Arthrocardia species (as Arthrocardia sp. 2) that is similar to A. carinata but has narrower intergenicula (up to 2.5 mm wide). So far Arthrocardia sp. 2 is known only from KwaZulu-Natal (Trafalgar Beach to Mission Rocks).

Arthrocardia carinata.

Arthrocardia carinata, herbarium specimen in Pocock collection (GRA).

Arthrocardia carinata, herbarium specimen (BOL).

Order Corallinales

Family Corallinaceae

Sub-Family Corallinoideae

Arthrocardia corymbosa (Lamarck) Decaisne 1842a: 380

Plants up to 10 cm high, pink, forming loose bushes; branching mainly dichotomous, occasionally pinnate or irregular; intergenicula terete or slightly flattened, up to 5 mm long, 0.5-1.0 mm wide; holdfast crustose. Genicula inconspicuous. Fertile intergenicula wedge-shaped with inconspicuous conceptacles with terminal ostiole.

Collections, ecology and regional distribution

Occurs from sublittoral fringe to at 12 m depth in exposed to semi-exposed locations, from False Bay to Mbotyi, Transkei (17-45).

World distribution: Also recorded from New Zealand (Adams 1994).

Type locality: Thought to be “Cape of Good Hope” (Silva et al 1996).

Note: In a DNA barcoding study by Kogame et al (2017), a single specimen from Bordjiesrif in False Bay (Western Cape) identified as this species, was confirmed as distinct from other South African Arthrocardia entities.

Arthrocardia corymbosa, herbarium specimen (BOL).

Arthrocardia corymbosa, herbarium specimen annotated and identified by HW Johansen (BOL).

Arthrocardia corymbosa, detail, herbarium specimen (BOL).

Arthrocardia corymbosa, fertile. Reproduced from Stegenga et al. (1997).

Order Corallinales

Family Corallinaceae

Sub-Family Corallinoideae

Arthrocardia duthieae Johansen 1969: 58, figs 28b,c (“duthiae”)

Plants 4-8 (-10) cm tall, pink to pale violet with white tips, axes complanate, forming bushy tufts attached by crustose holdfast. Basal 1-5 segments terete, about 2 (-2.5) mm long, about 1 mm in diameter, above that becoming cuneate and flattened and often markedly alate (winged) , 3-4 (-6) mm long and up to 6 mm wide at distal end. Branching pinnate, but sometimes more than 3 branches arising from a segment; finer branchlets of third or higher orders sometimes awl-shaped, terete or flattened. Final series of branchlets sometimes long (-6mm), terete, often pointed. Adventitious branching from faces of segments present (common in some specimens), usually from near the top of an axial segment. Genicula inconspicuous and barely visible. Fertile intergenicula (in distal parts of plant) each bearing swollen conceptacle at the top, with a single terminal ostiole.

Collections, ecology and regional distribution

A South African endemic, recorded from Stilbaai to Hluleka (26-45). Collected from the lower intertidal and from rock pools.

Type locality: “Blauwklip, near mouth of the Groote River (Keurbooms River), Knysna District, Cape Province, South Africa” (Silva et al. 1996).

Note: A DNA barcoding study by Kogame et al. (2017) confirmed a distinct clade of South African Arthrocardia fitting the description of this species. 

Arthrocardia duthieae, herbarium specimen (BOL).

Arthrocardia duthieae, detail, herbarium specimen (BOL).

Order Corallinales

Family Corallinaceae

Sub-Family Corallinoideae

Arthrocardia flabellata (Kützing) Manza 1940: 286

Plants up to 10 cm tall, bushy, bright pink to grayish-pink, axes complanate, often fan-shaped (flabellate). Holdfast crustose. Branching irregularly pinnate below, dichotomous in fertile areas above, adventitious branching rare. Intergenicula cylindrical near base of plant (0.5 – 1 mm diameter), flattened and cuneate above with margins becoming linear in most proximal segments, 1-3 mm long and up to 2 (-3) mm wide. Ultimate intergenicula sometimes incised (branched without articulations), and up to 8 mm long. Genicula visible as narrow line. Conceptacles prominent, developing in each segment, ostioles terminal. Male conceptacles with prominent beak up to 1.5 mm long.

Collections, ecology and regional distribution

Recorded along the whole South African coast, but probably less common west of Cape Point (Stegenga et al. 1997)(1-58). On the south coast this species is common in rock pools and in the lower eulittoral.

World distribution: Also recorded from Australia (type), Brazil, Mauritius and Mozambique (Guiry & Guiry 2014).

Type locality: Nora Creina, South Australia (Womersley & Johansen 1996).

Note: A DNA barcoding study by Kogame et al. (2017) confirmed the existence of a distinct clade of South African entities that fit the description of this species.

Arthrocardia flabellata, herbarium specimen (BOL).

Arthrocardia flabellata, detail of apices.

Arthrocardia flabellata, fertile branch system (reproduced from Stegenga et al. (1997).

Arthrocardia flabellata, male plant, note beaked conceptacles. (Reproduced from Stegenga et al. (1997).

Arthrocardia flabellata, sterile erect thallus (reproduced from Stegenga et al. (1997).

Order Corallinales

Family Corallinaceae

Sub-Family Corallinoideae

Arthrocardia palmata (J. Ellis & Solander) J.E. Areschoug in J. Agardh 1852: 549

Plants 2-3 (-6) cm tall, pink, fronds terete sometimes becoming slightly flattened in distal parts, mainly dichotomously branched, branching more frequent in distal parts. Branching mainly dichotomous (two branches arising from the distal end of a segment) but sometimes 3,4 or (very rarely) 5 branches arising together; adventitious branching present, sometimes from all sides of a segment. Basal segments entirely terete, about 1 mm long, 0.5 mm diameter; segments becoming longer distally to about 3 (-6) mm near tips of axes and slightly flattened at their distal ends where branches are borne; terminal segments often terete. Genicula in basal parts visible as dark lines, almost invisible towards tips of axes.

Fertile segments with single axial conceptacle visible as swelling in distal end, between the points where the branches are borne; single terminal ostiole.

Collections, ecology and regional distribution

Collected from Cape Padrone to Hluleka (38-45), from rock pools and the lower eulittoral.

World distribution: Also recorded from Namibia and Madagascar (Silva et al. 1996).

Type locality: “American Seas” but thought to be South Africa (Guiry & Guiry 2014).

Note: In a DNA barcoding study by Kogame et al. (2017), none of the 63 articulated coralline species collected on the South African coast was clearly identified (morphologically) as A. palmata, but a specimen from Palm Beach in southern KwaZulu-Natal (one of two assigned to a clade of two specimens called Arthrocardia sp. 1) appears very similar to this species. 

Arthrocardia palmata.

Arthrocardia palmata, herbarium specimen (BOL).

Arthrocardia palmata, detail of herbarium specimen (BOL).

Arthrocardia palmata, detail of herbarium specimen (BOL) showing branching pattern.

Order Corallinales

Family Corallinaceae

Sub-family Corallinoideae

Corallina Linnaeus

Thalli composed of calcified crustose holdfasts and erect, pinnately-branched fronds with calcified intergenicula (segments) linked by uncalcified genicula (articulations). Fertile intergenicula with single, terminal, swollen conceptacles, each with single, terminal ostiole and rarely with surmounting branchlets. (Pseudolateral conceptacles, when present, visible as swellings in surfaces of intergenicula). Gametophytes dioecious.

Members of this genus are ubiquitous in temperate and boreal waters. Twenty species are currently recognized worldwide (Guiry & Guiry 2014).

Only two Corallina species are recorded from the south coast: C. officinalis and C. berteroi. However, COI barcoding of several specimens identified as the former shows that they are different from European C. officinalis (Williamson et al. 2015; Kogame et al. 2017) and entities identifiable as C. berteroi have not been barcoded. It is clear that Corallina from South Africa needs further study.

Key to species

1 a. Branches mainly terete, long (to 5-6 mm), no adventitious branching from surface of segments

C. berteroi

1 b. Terminal branches subterete to compressed, short (to 1.5 mm), adventitious branching from (mainly proximal) surfaces of segments

Corallina sp. 1

Order Corallinales

Family Corallinaceae

Sub-family Corallinoideae

Corallina berteroi Montagne ex Kützing 1849: 709 (“berterii”)

Plants 2-6 cm high, chalky pink, forming tufts of erect, neatly bipinnate axes with a crustose base. Genicula inconspicuous. Intergenicula in main axes cylindrical below, becoming somewhat flattened and wedge-shaped above as result of lateral widening at distal ends where branches are borne, 0.8 to 1.2 mm long, 500-600 µm wide at bases, 800-1100 µm wide at distal ends; branchlets terete, up to 6 mm long, 200-300 µm in diameter, fertile branchlets terminal, short with swollen tips (conceptacles). Adventitious branching not seen.

Collections, ecology and distribution

Epilithic, on exposed shores in the lower eulittoral and sublittoral fringe. Recorded from Plettenberg Bay to Port Alfred (31-39).

World distribution: Fairly widely distributed in warm temperate and tropical seas (Guiry & Guiry 2014). The recorded localities range from tropical through to sub-Antarctic, suggesting that the species needs further taxonomic study.

Type locality: Chile (Silva et al. 1996).

Note: Except for one specimen (see below) we did not recognize this species in our collections, although it is recorded from the literature. There are 4 specimens in BOL labelled “cf berterii”, but two are useless fragments, and one appears to be a Haliptilon (now Jania). Only one (Keurboomstrand, coll & det Stegenga, BOL #16180), appears different to C. officinalis, and fits (to a reasonable extent) Kützing’s type description and Harvey’s description in Nereis Australis. These descriptions and this specimen are used here.

We do not know if this species is represented in the DNA barcoding study of Kogame et al. (2017), which identified two Corallina clades among (limited) South African samples. Any decision should await DNA analysis of C. berteroi from Chile, the type locality.

Corallina berteroi, detail (smallest scale divisions 1 mm).

Corallina berteroi, detail (scale bar 10 mm).

Order Corallinales

Family Corallinaceae

Sub-family Corallinoideae

Corallina sp 1 (“C. officinalis”)

Plants pink to purplish-pink or greyish, with a crustose base and many erect axes up to 8 cm tall, forming dense clumps usually with a pyramidal outline. Axes cylindrical to compressed, pinnately branched. Genicula with single transverse band of cells, inconspicuous. Intergenicula flattened to cuneate, 0.5 – 1.5 mm long, 0.5 – 1.5 mm broad; branching usually from every intergeniculum, sometimes more than one branch arising on one side of an axial segment; adventitious branching from surfaces of intergenicula may occur on proximal axes; apices of terminal segments rounded and pale, terminal segments sometimes spathulate. Fertile branchlets often resembling tiny clubs; conceptacles swollen, borne axially, ostiole terminal occasionally with short, thin surmounting branchlets.

Collections, ecology and regional distribution

Common and abundant on exposed rock in pools and gulleys from the lower eulittoral to shallow subtidal. Recorded (as C. officinalis) from Oudekraal (west coast of Cape Peninsula; Stegenga et al. 1997) to northern Kwazulu-Natal (De Clerck et al. 2005) (16-58).

Collections, ecology and regional distribution

Common and abundant on exposed rock in pools and gulleys from the lower eulittoral to shallow subtidal. Recorded (as C. officinalis) from Oudekraal (west coast of Cape Peninsula; Stegenga et al. 1997) to northern Kwazulu-Natal (De Clerck et al. 2005) (16-58).

Corallina sp 1, Arniston.

Corallina sp 1, detail of segments.

Corallina sp 1, fertile specimen, Tsitsikamma.

Corallina sp 1, branch detail.

Corallina sp 1. Habit (reproduced from Stegenga et al. 1997, as C. officinalis).

Order Corallinales

Family Corralinaceae

Subfamily Corallinoideae

Jania J.V. Lamouroux

Thalli comprising limited crustose bases or stoloniferous bases, and geniculate erect portions that are mainly dichotomously branched (pinnate branching present in some species); cells in genicula longer in centre than at edges, medullary cells of intergenicula 90-130 µm long; conceptacles originating in the medulla; tetrasporangial conceptacles each containing fewer than 15 tetrasporangia (adapted from Kim et al. 2007).

Note: Kim et al. (2007), on molecular and morphological grounds, subsume the genera Cheilosporum and Haliptilon into Jania. Accordingly, we treat all south coast members of the first two genera as belonging to Jania. However, it should be noted that some authors question these combinations (e.g. Williamson et al. 2015; Kogame et al. 2017) and continue to treat these three genera as separate.

Key to south coast Jania

1 a. Branching dichotomous throughout thallus

2

1 b. Branching dichotomous in main axes, pinnate in distal axes

Jania subulata

2 a. All segments cylindrical to subcylindrical

5

2 b. Middle and upper segments with bilateral lobes or projections

3

3 a. Middle-upper segments arrowhead-shaped, wings pointed and often reflexed (curved away from axis)

Jania sagittata

3 b. Wings broad or poorly-developed and variously-shaped

4

4 a. Wings well-developed, with pointed, blunt or incised edges, segments 0.6-1mm long in the middle

Jania cultrata

4 b. Wings on same thallus often variously-shaped, segments 1-3 m long in the middle

Jania prolifera

5 a. Plants delicate, small (to 10 mm high), segments 40-100 µm in diameter

Jania capillacea

5 b. Plants more robust, a few to 10 cm tall, segments usually over 100 µm diameter

6

6 a. Plants tall, usually 4-8 (-10) cm, segments more than 100 µm diameter, branch angles usually less than 30º

Jania verrucosa

6 b. Plants 2-5 cm tall, segments 60-130 (-170) µm diameter, branch angles usually more than 45o, fertile segments much larger than vegetative segments

Jania adhaerens

Order Corallinales

Family Corallinaceae

Subfamily Corallinoideae

Jania adhaerens Lamouroux 1816: 270

Plants small (to 2.5 cm tall), grayish to pink, often entangled with other algae and forming dense, short turfs. Holdfast stoloniferous, cylindrical, 70-100 µm diameter, with small discoid attachments. Axes rather irregularly dichotomously branched, branch angle usually more than 45o. Genicula inconspicuous. Intergenicula cylindrical to subcylindrical, 60-130(170) µm diameter, 2-5 times as long as wide. Fertile intergenicula axial, flask-shaped, much wider than vegetative segments, each bearing a single swollen conceptacle with pore in upper edge of intergeniculum, and one or two distal branches.

Collections, ecology and regional distribution

Epilithic and epiphytic, commonly as main component of low, sandy turfs in the lower eulittoral and shallow sublittoral zones. Found from Cape Hangklip eastward to northern KwaZulu –Natal (19-58).

World distribution: worldwide in tropical and warm temperate oceans (Guiry & Guiry 2014).

Type locality: Meditterannean Sea (Lamouroux 1816).

Note: Stegenga et al. (1997) report that many specimens from west of Cape Agulhas have dimensions intermediate between those of J. capillacea Harvey (about 60 µm diameter) and J. adhaerens (120-200 µm diameter), suggesting that these species need further study.

Jania adhaerens, on sand-affected rocks, Nature’s Valley.

Jania adhaerens, herbarium specimen (scale on left in 1mm divisions).

Jania adhaerens, detail (scale bar = 1 mm).

Jania adhaerens, . 1. Detail of plant with tetrasporangial conceptacles. 2. Tetrasporangium. Reproduced from Stegenga et al. (1997).

Order Corallinales

Family Corallinaceae

Subfamily Corallinoideae

Jania capillacea Harvey 1853: 84

Plants very delicate, forming dense clumps or cushions a few to about 10 mm tall, pinkish-red: holdfasts of small crusts or discs; axes cylindrical, sometimes curved inwards, tips pointed or sometimes rounded, branching dichotomous. Genicula inconspicuous. Intergenicula calcified, 300-600 µm long and 40-100 µm in diameter; fertile intergenicula larger than vegetative intergenicula, flask-shaped, with apical pore.

Collections, ecology and regional distribution

Epilithic or often epiphytic, in rock pools, lower eulittoral and sublittoral fringe. In our collections found only at De Hoop, Hluleka and Haga-Haga.

World distribution: Widespread in tropical and warm temperate regions (Guiry & Guiry 2014).

Type locality: Florida, USA (Yoshida 1998).

Note: We consider that this species may be a smaller form of J. adhaerens: further studies are required.

Jania capillacea, herbarium specimen (scale divisions = 1mm).

Jania capillacea, vegetative tip of thallus, Kei Mouth.

Order Corallinales

Family Corallinaceae

Subfamily Corallinoideae

Plants pink, bushy, with erect axes up to 6 (-8) cm high. Axes mainly in one plane, dichotomously branched. Segments in upper parts of thallus distinctively winged, 0.5 – 1.0 (-2) mm high in the middle, up to 2.5 (-4) mm across apices of wings, tips of wings pointed, blunt, or variously incised. Lobe angle 30-75o. Holdfast of tangled stolons with terete, un-lobed segments 0.3-0.5 mm long, 0.2-0.5 mm in diameter. Adventitious branches from surfaces of segments rare. Genicula barely visible. Conceptacles 1-3 per lobe, visible as swellings in upper margins of lobes.

Collections, ecology and regional distribution

Found in the sublittoral fringe and shallow sublttoral zone. Recorded from False Bay along the whole south coast and Kwazulu-Natal (17-58) into Mozambique.

World distribution: Recorded from various localities in the tropical Indian Ocean and from Micronesia in the Pacific Ocean (Guiry & Guiry 2014).

Type locality: Durban, South Africa.

Note: 1. This species contains two entities that were formerly recognized as subspecies of Cheilosporum cultratum: (subsp cultratum and subsp multifidum).
2. In a DNA barcoding study (Kogame et al. 2017) this species formed a morphologically identifiable and well-supported clade.
3. There are two morphotypes of Jania cultrata specimens in BOL (as C. cultratum). South coast specimens are relatively fine (smaller segments: 0.5-1.0 mm long, 1.8 to 2.5 mm across tips), grayish, and shorter. Some KZN specimens (e.g. BOL 15959, from Palm Beach) are brighter pink and larger in all respects (up to 8 cm tall, segments up to 2 mm long and 4 mm across apices).

Jania cultrata, De Hoop.

Jania cultrata, detail of segment shape.

Jania cultrata, herbarium specimen.

Order Corallinales

Family Corallinaceae

Subfamily Corallinoideae

Jania prolifera (J.V.Lamouroux) J.H.Kim, Guiry & H.-G.Choi 2007: 1317, nom. illeg.

Plants pink, bushy, up to 12 cm tall. Axes complanate, dichotomously branched, often with thin (to 300 µm diameter) branches arising from distal parts. Branch apices rounded and often bleached. Adventitious branching from surfaces of some segments. Lower segments on plants un-lobed, terete to compressed, 0.5-2.0 mm long, 0.5-1.2 mm in diameter; distal segments compressed, variously shaped (arrow-head, bi-lobed, or rectangular), 0.3-3 mm long and 1-3 mm across apices of lobes; lobes simple and project upwards, lobe angle 10-45o. Genicula inconspicuous. Holdfast of entangled stolons of terete to subterete, un-lobed segments 200-1000 µm in diameter. Conceptacles swollen, borne on upper edges of segments, ostiole opening on upper edge.

Collections, ecology and regional distribution

Found in rock pools, the sublittoral fringe and sublittoral zone to at least 10 m depth. Recorded from Stilbaai through KwaZulu-Natal (26-58) into Mozambique.

World distribution: Also reported from Madagascar and Australia (Silva et al. 1996).

Type locality: Recorded as “Indes Orientales” - probably Madagascar, according to Papenfuss (1952).

Note: A single specimen morphologically identified as Cheilosporum proliferum (Jania prolifera) formed a clade (CO1 barcoding) distinct from the other Cheilosporum /Jania species in South Africa (Kogame et al. 2017).

Jania prolifera, herbarium specimen collected from 5-10 m depth, Stilbaai.

Jania prolifera, detail of Stilbaai specimen showing adventitious branches.

Jania prolifera, with profuse adventitious branches.

Order Corallinales

Family Corallinaceae

Subfamily Corallinoideae

Jania sagittata (J.V.Lamouroux) Blainville 1834: 550, [Atlas] pl. 96: figs 2, 2a

Plants pink, bushy, with erect axes up to 7 (-9) cm high. Axes usually complanate, dichotomously branched; branch apices rounded, bleached, sometimes black when dry. Lower segments on plants terete, 0.5-1.0 mm long and about 0.5 m in diameter: upper segments compressed, bi-lobed and shaped like a slender arrowhead, 0.5-1.5 mm long and up to 3 mm across the tips of the lobes; lobes simple, upper apices sharply pointed, often curved outward, lobe angle 25-45o. Genicula inconspicuous. Holdfast of entangled stolons of terete to subterete, un-lobed segments 200-500 µm in diameter. Conceptacles swollen, borne on upper edges of segments, ostiole opening through surface of segment or through upper edge.

Collections, ecology and regional distribution

Found in rock pools, the sublittoral fringe and sublittoral to at least 24 m depth. Recorded from Melkbosstrand (near Cape Town) to northern Kwazulu-Natal (15-58 )(De Clerck et al. 2005).

World distribution: Also reported from Mauritius, Kenya, Somalia and Brazil, Philippines, Indonesia, Australia and New Zealand (Guiry & Guiry 2014).

Note: Previously known as Cheilosporum sagittatum.

Jania sagittata, Arniston.

Jania sagittata, herbarium specimen.

Jania sagittata, detail of segments.

Jania sagittata, herbarium specimen, detail.

Jania sagittata. Reproduced from Stegenga et al. (1997)(as Cheilosporum sagittatum).

Order Corallinales

Family Corallinaceae

Subfamily Corallinoideae

Jania subulata (Ellis & Solander) Sonder 1848: 186

Plants pink, rather delicate, to 5 (-7) cm tall, profusely branched, with complanate axes and proliferation of short terminal branchlets, holdfast crustose. Branching dichotomous in main axes, with pinnate (opposite) branching in subsidiary axes; numerous terete or slightly compressed terminal branchlets impart somewhat feather-like appearance to axes. Basal segments terete to slightly flattened, 100-250 µm diameter; middle segments compressed, 0.7 – 1.0 mm diameter, 0.3-0.7 mm long. Branchlets terete to flattened, 100-300 µm in diameter, forked or unbranched, often tapering distally. Intergenicula inconspicuous. Conceptacles in distinctly swollen (to 400 µm diameter) terminal segments of axes or branchlets, often with lateral branchlets around them.

Collections, ecology and regional distribution

Epilithic or epiphytic in rock pools, lower eulittoral or sublittoral fringe. Recorded from just west of Port Elizabeth through to northern Kwazulu-Natal (35-58).

World distribution: Widespread in warm temperate and tropical seas (Guiry & Guiry 2014).

Type locality: West Indies (Silva et al. 1996).

Jania subulata, herbarium specimen.

Jania subulata, herbarium specimen.

Jania subulata, detail of herbarium specimen.

Order Corallinales

Family Corallinaceae

Subfamily Corallinoideae

Jania verrucosa Lamouroux 1816: 270, pl. 9, fig. 4 nom. rejic

See notes (below) on the application of this name.

Plants erect, up to 6 (-10) cm tall, pale reddish to pink, in sandy turfs or as larger individuals. Basal portions stoloniferous; erect axes regularly dichotomously branched in many planes, branch angle narrow (< 30o), branches often parallel near point of origin. Genicula inconspicuous. Intergenicula calcified, cylindrical to subcylindrical, about 500 µm diameter in proximal part of thallus, narrowing to about 150 µm near apices, 1-3 times longer than broad, those subtending branches somewhat broader and flattened. Tips of branches bleached, acute or bifurcating, sometimes with a median longitudinal depression. Fertile intergenicula triangular, usually forming base of dichotomy but sometimes terminal; conceptacle swollen with pore on upper edge of geniculum.

Collections, ecology and distribution

Common in sand-binding turfs, but may occur as larger, individual plants. Epilithic, occasionally epiphytic, in rock pools, sublittoral fringe and sublittoral zone to at least 8m depth. Typically in sandy, wave-exposed environments. Found from False Bay eastward to northern KwaZulu-Natal (17-58), but see notes 1-3 below.

World distribution: Widespread in warm temperate and tropical regions, but taxonomic and nomeclatural uncertainties mean that distributions cannot be established without further study (Guiry & Guiry 2016).

Type locality: Amérique méridionale (“Central America”) (Silva et al. 1996), but see notes.

Notes: 1. This name is “of uncertain nomenclatural application” (MD Guiry in Guiry & Guiry 2016) and no clear type can be found– see Woelkerling et al. (2015).
2. We use the name to include entities previously recorded as Jania crassa Lamouroux and J. natalensis Harvey.
3. A recent genetic barcoding study of South African articulated corallines (Kogame et al. 2017) showed that even among a limited sample of specimens identified as J. verrucosa, there were two distinct entities.
4. J. verrucosa differs from Jania adhaerens in having larger dimensions and narrower branch angles.

Jania verrucosa, Qologha, east of Kei Mouth.

Jania verrucosa, herbarium specimen.

Jania verrucosa. 1. Detail of (small) plant with tetrasporangial conceptacles. 2. Tetrasporangium. 3. Habit of large plant (apex). Reproduced from Stegenga et al. (1997).

Family Corallinaceae

Subfamily Metamastophoroideae

Metamastophora flabellata (Sonder) Setchell 1943: 131

Plants erect, pink to purplish with bluish iridescence when fresh, comprising compressed to flattened uprights up to about 20 cm tall, somewhat calcified, arising from a discoid holdfast. Stipe short, up to 2 mm wide, compressed. Axes irregularly to dichotomously branched, usually 1.5-2 mm wide but may widen to about 10 mm wide near the flabelliform apices; apices and blade margins usually downward-curved. Internal structure pseudoparenchymatous, with some dorso-ventral organization. Reproductive structures in swollen conceptacles borne singly or in groups on dorsal surface of blades.

Collections, ecology and regional distribution

Epilithic or epiphytic, from the lower eulittoral down to at least 37 m. Recorded from Hluleka to northern Kwazulu-Natal (45-58).

World distribution: Mozambique, Australia, Micronesia, Israel (Guiry & Guiry 2015).

Type locality: Western Australia, near mouth of Swan River (Silva et al. 1996).

Metamastophora flabellata, Mzamba.

Metamastophora flabellata, conceptacles.

Metamastophora flabellata, (BOL), showing size of thalli

Order Hapalidiales

Family Hapalidiaceae

Subfamily Choreonematoideae

Choreonema thuretii (Bornet) F.Schmitz 1889: 455

Plants borne on certain geniculate corallines (e.g. Jania spp.), usually 0.2 – 1 mm in size, comprising endophytic vegetative portions that produce globular conceptacles external to the host. Structure diffuse, filamentous to partly pseudoparenchymatous, comprising simple or branched filaments 5 – 20 µm in diameter, within the host tissue; conceptacles almost completely external to host tissue, whitish, globular to urceolate, about 100-120 µm in diameter, containing tetrasporangia, carposporangia or spermatangial filaments.

Collections, ecology and regional distribution

Recorded from False Bay in the Western Cape to the Durban area of KwaZulu-Natal (18-51), as an endophyte on certain geniculate coralline species.

World distribution: Widespread in tropical and warm temperate regions, including Mozambique and Mauritius (Guiry & Guiry 2015).

Type locality: Atlantic France (Guiry & Guiry 2015).

Note: See Womersley (1996) for a detailed description and illustrations of Australian material.

Choreonema thuretii on Jania sp. (Double Mouth).

REFERENCES

References to South Coast Rhodophyta - Book 6

Abbott, I.A. 1999. Marine Red Algae of the Hawaiian Islands. Bishop Museum Press. Honolulu, Hawai’i, 477 pp.

Adams, N. M. 1994. Seaweeds of New Zealand. An Illustrated Guide. Christchurch, Canterbury University Press.

Agardh, C.A. 1817. Synopsis algarum Scandinaviae, adjecta dispositione universali algarum. pp. [i]-xl, [1]-135. Lundae [Lund]: ex officina Berlingiana.

Agardh, J.G. 1841. In historiam algarum symbolae. Linnaea 15: 1-50, 443-457.

Agardh, J.G. 1852. Species genera et ordines algarum, seu descriptiones succinctae specierum, generum et ordinum, quibus algarum regnum constituitur. Volumis secundi: Algas florideas complectens. Part 2, fasc. 2. pp. 577-700 [701-720, Addenda and Index]. Lundae [Lund]: C.W.K. Gleerup.

Agardh, J.G. 1863. Species genera et ordines algarum, seu descriptiones succinctae specierum, generum et ordinum, quibus algarum regnum constituitur. Volumen secundum: algas florideas complectens. Part 2, fasc. 3. pp. 787-1138, 1158-1291. Lundae [Lund]: C.W.K. Gleerup.

Agardh, J.G. 1892. Analecta algologica. Acta Universitatis Lundensis 28(6): 1-182, 3 pls.

Agardh, J.G. 1894. Analecta algologica. Continuatio II. Acta Universitatis Lundensis Afd. 2 30(7): 1-99, 1 plate.

Agardh, J.G. 1897. Analecta algologica. Continuatio IV. Lunds Universitets Års-Skrift, Andra Afdelningen, Kongl. Fysiografiska Sällskapets i Lund Handlingar 33(9): 106, 2 plates.

Alongi, G., Cormaci, M. & Furnari, G. 2007. Woelkerlingia minuta gen. et sp. nov. from the Mediterranean Sea and a reassessment of the genus Lomathamnion, with a description of two new genera: Hommersandiella gen. nov. and Stegengaea gen. nov. Cryptogamie, Algologie 28: 311-324.

Ambronn, H. 1880. Über einige Fälle von Bilateralität bei den Florideen. Botanische Zeitung 38: 161-174, 177-185, 193-200, 209-216, 225-233, Plates III, IV.

Anderson, R.J. & Stegenga, H. 1989. Subtidal algal communities at Bird Island, Eastern Cape, South Africa. Botanica Marina 32: 299-311.

Ardré, F. 1967. Remarques sur la structure des Pterosiphonia (Rhodomélacées, Céramiales) et leurs rapports systématiques avec les Polysiphonia. Revue Algologique, Nouvelle Serie 9: 37-77, VI plates.

Askenasy, E. 1888. Algen mit Unterstützung der Herren E. Bornet, E. Grunow, P. Hariot, M. Moebius, O. Nordstedt bearbeitet. In: Forschungsreise S.M.S. "Gazelle". Theil 4: Bot. (Engler, A. Eds), pp. 1-58. Berlin.

Athanasiadis, A. 1996. Morphology and classification of the Ceramioideae (Rhodophyta) based on phylogenetic principles. Opera Botanica 127: 1-221.

Baldock, R.N. 1976. The Griffithsieae group of the Ceramiaceae (Rhodophyta) and its southern Australian representatives. Australian Journal of Botany 24: 509-593, 92 figs.

Blainville, H.M.D. de 1834. Manuel d'actinologie ou de zoophytologie, contenant 1. Une histoire abrégée de cette partie de la zoologie, avec des considérations générales sur l'anatomie, la physiologie, les moeurs, les habitudes et les usages des Actinozoaires; 2. Un système général d'Actinologie, tiré à la fois des animaux et de leurs parties solides ou polypiers; 3. Un catalogue des principaux auteurs qui ont écrit sur ce sujet. Avec un atlas de 100 planches représentant une espèce de chaque genre et sous-genre. pp. [i]-viii, [1]-694, [i, err.], Atlas: 103 copper engravings by Prêtre ("pinxit"), Turpin ("direxit") and Massard ("sculpsit"). Paris & Strasbourg: F.G. Levrault.

Bolton, J.J. & Stegenga, H. 1987. The marine algae of Hluleka (Transkei) and the warm temperate/subtropical transition on the east coast of southern Africa. Helgoländer Meeresuntersuchungen 41: 165-183.

Børgesen, F. 1910. Some new or little known West Indian Florideae. II. Botanisk Tidsskrift 30: 177-207, 20 figs.

Bornet, E. 1892. Les algues de P.-K.-A. Schousboe. Mémoires de la Société des Sciences Naturelles et Mathématiques de Cherbourg 28: 165-376, pls I-III.

Branch, G.M., Griffiths, C.L., Branch, M.L., & Beckley, L.E. 2017. Two Oceans: A guide to the marine life of southern Africa, 4th edition. Struik Nature, Cape Town.

Cassano, V., Oliveira, M.C., Gil-Rodriguez, M.C., Senties, A., Diaz-Larrea, J., & Fujii, M.T. 2012. Molecular support for the establishment of the new genus Laurenciella within theLaurencia complex (Ceramiales, Rhodophyta). Botanica Marina. 55 (4) pp. 349 – 357.

De Clerck, O, Tronchin, E. M., & Schils, T. 2005. Red algae. In: De Clerck, O., J.J. Bolton, R. J. Anderson & Coppejans, E. 2005. Guide to the Seaweeds of Kwazulu-Natal. National Botanic Garden of Belgium, Brussels (Scripta Botanica Belgica), pp. 130-269.

De Toni, G.B. (1903). Sylloge algarum omnium hucusque cognitarum. Vol. IV. Florideae. Sectio III . pp. [i], frontispiece, [iii-v], 775, 775 bis, 776, 777 bis, 777-1521 + 1523-1525. Patavii [Padua]: Sumptibus auctoris.

Decaisne, J. 1842. Essais sur une classification des algues et des polypieres calcifères de Lamouroux. Mémoire sur les corallines ou polypiers calcifères. Annales des Sciences Naturelles. Botanique, sér 2, 18: 96-128.

Decaisne, J. 1842. Mémoires sur les corallines ou polypiers calcifères. Annales des Sciences Naturelles, Botanique, Série 2 16: 85-120.

Falkenberg, P. 1901. Die Rhodomelaceen des Golfes von Neapel und der angrenzenden Meeres-Abschnitte. Fauna und Flora des Golfes von Neapel, Monographie 26. pp. i-xvi, 1-754, 10 figs, 24 pls. Berlin.

Francis, C.M. 2014. Systematics of the Laurencia complex (Rhodomelaceae, Rhodophyta) in southern Africa. PhD Thesis, University of Cape Town, 199 pp.

Francis, C.M., Bolton, J.J, Mattio, L. Mandiwana-Neudani, T.G., & Anderson, R.J. 2017. Molecular systematics reveals increased diversity within the South African Laurencia complex (Rhodomelaceae, Rhodophyta). Journal of Phycology 53: 804-819.

Garbary, D.J. & Harper, J.T. 1998. A phylogenetic analysis of theLaurencia complex (Rhodomelaceae) of the red algae. Cryptogamie Algologie 19 pp. 185 – 200.

Gil-Rodriguez, M.C., Sentìes, A., Dìaz-Larrea, J., Cassano, V. & Fujii, M.T. 2009. Laurencia marilzae sp. nov. (Ceramiales, Rhodophyta) from the Canary Islands, Spain, based on morphological and molecular evidence. Journal of Phycology. 45 pp. 264 – 271.

Gordon, E.M. 1972. Comparative morphology and taxonomy of the Wrangelieae, Sphondylothamnieae and Spermothamnieae (Ceramiaceae, Rhodophyta). Australian Journal of Botany Suppl. 4: 1-180, 63 figs, 3 tables.

Gordon-Mills, E. & Norris, R.E. 1986. Shepleya elixithamnia, a new species of Ceramiaceae (Rhodophyta) from South Africa. Phycologia 25: 160-167.

Guiry M.D. in Guiry, M.D. & Guiry, G.M. 2014. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 14 March 2014.

Guiry, M.D. in Guiry, M.D. & Guiry, G.M. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched at various times between November 2015 and August 2017.

Guiry, M.D. & Guiry, G.M. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on numerous occasions between October 2010 and August 2017.

Guiry, W. in Guiry, M.D. & Guiry, G.M. 2016. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 07 June 2016.

Harvey, W.H. 1833. Div. II. Confervoideae; Div. III. Gloiocladeae. In: The English Flora of Sir James Edward Smith. Class XXIV. Cryptogamia. Vol. V. (or Vol. II of Dr. Hooker's British flora). Part I. Comprising the Mosses, Hepaticae, Lichens, Characeae and Algae . (Hooker, W.J. Eds), pp. 263-265, 265-266, 326-389, 389-405. London: Longman, Brown, Green & Longmans Paternoster-Row.

Harvey, W.H. 1847. Nereis australis, or algae of the southern ocean: being figures and descriptions of marine plants, collected on the shores of the Cape of Good Hope, the extra-tropical Australian colonies, Tasmania, New Zealand, and the Antarctic regions; deposited in the Herbarium of the Dublin University. [Part 1]. pp. i-viii, 1-64, pls I-XXV. London: Reeve Brothers.

Harvey, W.H. 1849. Nereis australis, or algae of the southern ocean: being figures and descriptions of marine plants, collected on the shores of the Cape of Good Hope, the extra-tropical Australian colonies, Tasmania, New Zealand, and the Antarctic regions; deposited in the Herbarium of the Dublin University. Part 2. pp. 65-124, Plates XXVI-L. London: Reeve Brothers.

Harvey, W.H. 1853. Nereis boreali-americana; or, contributions towards a history of the marine algae of the atlantic and pacific coasts of North America. Part II. Rhodospermeae. Smithsonian Contributions to Knowledge 5(5): [i-ii], [1]-258, pls XIII-XXXVI.

Harvey, W.H. 1855. Some account of the marine botany of the colony of western Australia. Transactions of the Royal Irish Academy 22: 525-566.

Harvey W. H. 1862. Phycologia Australica. Vol. 4, pl. 181-240. Reeve, London.

Henderson, R.J.F., Wilson, S.M. & Kraft, G.T. 2001. Kentrophora S.M. Wilson & Kraft, a new name for an algal genus in tribe Amansieae (Rhodomelaceae, Rhodophyceae). Austrobaileya 6: 175-176.

Jaasund, E. 1976. Seaweeds in Tanzania: A field guide. Tromsø: University of Tromsø. 166 pp.

Jackelmann, J.J., Stegenga, H. & Bolton, J.J. 1991. The marine benthic flora of the Cape Hangklip area and its phytogeographical affinities. South African Journal of Botany 57: 295-304, 4 figs, 1 table.

Johansen, H.W. 1968. Reproduction of the articulated coralline Amphiroa ephedraea. Journal of Phycology 4: 319-328, 26 figs.

Johansen, HW 1984 The articulated coralline genus Arthrocardia in the southern hemisphere. British Phycological Journal 19: 195 (abstract).

John, D.M., Prud'homme van Reine, W.F., Lawson, G.W., Kostermans, T.B. & Price, J.H. 2004. A taxonomic and geographical catalogue of the seaweeds of the western coast of Africa and adjacent islands. Beihefte zur Nova Hedwigia 127: 1-339, 1 fig.

Karsakoff, N. 1896. Sur deux Floridées nouvelles pour la flore des Canaries. Annales des Sciences Naturelles, Botanique, Série 8 4: 281-288, pl. 3.

Kim, J. H., Guiry M. D., Oak, J. H., Choi, D. S., Hosung Chung, S-H. K., & Choi, H-G. 2007. Phylogenetic relationships within the tribe Janieae (Corallinales, Rhodophyta) based on molecular and morphological data: A reappraisal of Jania. Journal of Phycology 43: 1310-1319.

Kim, M.-S. & Lee, I.K. 1999. Neosiphonia flavimarina gen. et sp. nov. with a taxonomic reassessment of the genus Polysiphonia (Rhodomelaceae, Rhodophyta). Phycological Research 47: 271-281.

King, R.J. & Puttock,C. 1989. Morphology and taxonomy ofBostrychia and Stictosiphonia (Rhodomelaceae/Rhodophyta). Australian Systematic Botany 2: 1-73.

Kogame, K., Uwai, S., Anderson, R.J., Choi, H-G. & Bolton, J.J. 2017. DNA barcoding of South African geniculate coralline red algae (Corallinales, Rhodophyta). South African Journal of Botany 108: 337-341.

Kützing, F.T. 1849. Species algarum. pp. [i]-vi, [1]-922. Lipsiae [Leipzig]: F.A. Brockhaus.

Kylin, H. 1938. Verzeichnis einiger Rhodophyceen von Südafrika. Acta Universitatis Lundensis 34(8): 1-26, 10 figs, 8 plates

Kylin, H. 1956. Die Gattungen der Rhodophyceen. pp. i-xv, 1-673, 458 figs. Lund: C.W.K. Gleerups.

Lambert, G., Steinke T.D & Y Naidoo. 1987. Algae associated with mangroves in southern African estuaries. I. Rhodophyceae. South African Journal of Botany 53 (5): 349-361.

Lamouroux J. V. 1816. Histoires des polypieres coralligènes flexibles vulgairement nommés zoophytes. Caen, 559 pp., pl. 1-19.

Lawson, GW & John, DM, 1982. The marine algae and coastal environment of tropical West Africa. Beihefte zur Nova Hedwigia, 70: 1-455.

Maggs, C.A. & Hommersand, M.H. 1993. Seaweeds of the British Isles. Volume 1. Rhodophyta. Part 3A. Ceramiales . pp. [i]-xv, 1-444, 129 figs, map. London: HMSO.

Mamoozadeh, N.R. & Freshwater, D.W. 2012. Polysiphonia sensu lato (Ceramiales, Florideophyceae) species of Caribbean Panama including Polysiphonia lobophoralis sp. nov. and Polysiphonia nuda sp. nov.. Botanica Marina 55(4): 317-347.

Maneveldt, G.W., van der Merwe, E., & Keats, D.W. 2016 Updated keys to the non-geniculate coralline red algae (Corallinophycidae, Rhodophyta) of South Africa. South African Journal of Botany 106: 158–164.

Manza, A. V. 1940: A revision of the genera of articulated corallines. Philippine Journal of Science, 71: 239-316.

Martin, M.T. & Pocock, M.A. 1953. South African parasitic Florideae and their hosts. 2. Some South African parasitic Florideae. Journal of the Linnean Society of London, Botany 55: 48-64, 7 figs, pls 10-12.

Martin-Lescanne, J., Rousseau, F., De Reviers, B., Payri, C., Couloux, A., Cruaud, C. & Le Gall, L. 2010. Phylogenetic analyses of the Laurencia complex (Rhodomelaceae, Ceramiales) support recognition of five genera: Chondrophycus, Laurencia, Osmundea, Palisada and Yuzurua stat. nov. European Journal of Phycology, 45 (1) pp. 51 – 61.

Millar, A.J.K. 1990. Marine red algae of the Coffs Harbour region, northern New South Wales. Australian Systematic Botany 3: 293-593, 76 figs, 2 tables.

Montagne, C. 1840. Seconde centurie de plantes cellulaires exotiques nouvelles. Décades I et II. Annales des Sciences Naturelles, Botanique, Seconde Série 13: 193-207, pls 5, 6.

Montagne, C. 1842. Bostrychia. Dictionnaire Universel d'Histoire Naturelle [Orbigny] 2: 660-661.

Montagne, C. 1842. Botanique. Plantes cellulaires. In: Histoire physique, politique et naturelles de l'île de Cuba. (Sagra, R. De La Eds) Vol. 11, pp. i-x, 1-549. Paris.

Montagne, C. 1852. Diagnoses phycologicae, seu quibus characteribus, discriminandae sunt species lichenum algarumque nonnullae novae, in tomo Florae chilensis octavo nondum typis mandato descriptae. Annales des Sciences Naturelles, Botanique, sér. 3 18: 302-319.

Nägeli, C. 1862 '1861'. Beiträge zur morphologie und systematik der Ceramiaceae. Sitzungsberichte der Königlichen Bayerischen Akademie der Wissenschaften zu München 1861(2): 297-415, 30 figs, 1 pl.

Nam, K.W. & Kang, P.J. 2012. Algal flora of Korea. Volume 4, Number 4. Rhodophyta: Ceramiales: Rhodomelaceae: 18 genera including Herposiphonia . pp. [1-6], 1-178, figs 1-102. Incheon: National Institute of Biological Resources.

Nam, K.W., Maggs, C.A. and Garbary, D.J. 1994. Resurrection of the genusOsmundea with an emendation of the generic delineation of Laurencia (Ceramiales, Rhodophyta). Phycologia 33(5) pp. 384-395.

Norris, R.E. 1985. Studies on Pleonosporium and Mesothamnion (Ceramiaceae, Rhodophyta) with a description of a new species from Natal. British Phycological Journal 20: 59-68, 28 figs.

Norris, R.E. 1988. A review of Colacopsis and Melanocolax, red algal parasites on South African Rhodomelaceae (Rhodophyta). British Phycological Journal 23: 229-237, 12 figs, 1 table.

Norris, R.E. 1991. The structure, reproduction and taxonomy ofVidalia and Osmundaria (Rhodophyta, Rhodomelaceae). Journal of the Linnean Society of London, Botany 106: 1-40, 60 figs.

Norris, R. E. 1992a. Six marine macroalgal genera new to South Africa. South African Journal of Botany 58: 2-12.

Norris, R.E. 1992b. Ceramiales (Rhodophyceae) genera new to South Africa, including new species of Womersleyella and Herposiphonia. South African Journal of Botany 58: 65-76, 32 figs.

Norris, R.E. & Aken, M.E. 1985. Marine benthic algae new to South Africa. South African Journal of Botany 51: 55-65, 31 figs, 2 tables.

Norris, R.E. & Molloy,F. 1988. Griffithsia schousboei (Ceramiaceae, Rhodophyceae), a species new to South Africa. South African Journal of Botany 54(5): 477-480.

Okamura, K. 1907. Icones of Japanese Algae. Vol. I pp. 65-92, pls XVI-XX. Tokyo: The Author.

Oliveira, E., Österlund, K. & Mtolera, M.S.P. 2005. Marine Plants of Tanzania. A field guide to the seaweeds and seagrasses . pp. 267, Numerous coloured illustrations and line drawings. Stockholm: Botany Department, Stockholm University.

Papenfuss, G.F. 1943. Notes on South African marine algae II. Journal of South African Botany 9 pp. 79-92.

Papenfuss, G.F. 1947. New marine algae from South Africa; I. University of California Publications in Botany 23: 1-15.

Papenfuss, G.F. 1952. Notes on South African marine algae. III. Journal of South African Botany 17: 167-188.

Papenfuss, G. F. 1956: Notes on South African marine algae IV. Journal of South African Botany 22: 65-77.

Papenfuss, G.F. 1968. Notes on South African marine algae. V. Journal of South African Botany 34: 267-287.

Pocock, M.A. 1953. South African parasitic Florideae and their hosts. 1. Four members of the Rhodomelaceae which act as hosts for parasitic Florideae. Journal of the Linnean Society of London, Botany 55: 34-47, 9 figs, Plates 5-9.

Pocock, M.A. 1956. South African parasitic Florideae and their hosts. 3. Four minute parasitic Florideae. Proceedings of the Linnean Society of London 167: 11-41, 6 figs, 6 plates.

Post, E. 1936. Systematische und pflanzengeographische Notizen zur Bostrychia-Caloglossa Assoziation. Revue Algologie 9: 1-84.

Post, E. 1939. Bostrychia tangatensis spec. nov., eine neueBostrychia der ostafrikanischen Mangrove. Archiv für Protistenkunde 92: 152-156, 1 fig, 1 table.

Price, J.H., John, D.M. & Lawson, G.W. 1986. Seaweeds of the western coast of tropical Africa and adjacent islands: a critical assessment. IV. Rhodophyta (Florideae). 1. Genera A-F. Bulletin of the British Museum (Natural History) Botany 15: 1-122, 1 fig.

Rull Lluch, J. 2002. Marine benthic algae of Namibia. Scientia Marina 66 (Supplement 3): 258 pp.

Saenger, P.1971. On the occurrence of Ophidocladus (Rhodomelaceae) in southern Africa. Journal of South African Botany, 37: 291-304, figs 1-8.

Savoie, A.M. & Saunders, G.W. 2016. A molecular phylogenetic and DNA barcode assessment of the tribe Pterosiphonieae (Ceramiales, Rhodophyta) emphasizing the Northeast Pacific. Botany 94: 917-939, 8 figs.

Scagel R. F. 1953. A morphological study of some dorsiventral Rhodomelaceae. University of California Publications in Botany 27: 1-108.

Scagel, R.F. 1962, The genus Dasyclonium J. Agardh. Canadian Journal of Botany 40: 1017-1040.

Schmitz, F. 1889. Systematische Übersicht der bisher bekannten Gattungen der Florideen. Flora oder Allgemeine botanische Zeitung 72: 435-456, pl. XXI.

Schmitz, F. 1895. Marine Florideen von Deutsch-Ostafrica. Botanische Jahrbücher für Systematik, Pflanzengeschichte und Pflanzengeographie 21: 137-177.

Schmitz, F. 1896. Kleinere Beiträge zur Kenntniss der Florideen. VI. Nuova Notarisia 7: 1-22.

Schmitz, F. & Falkenberg, P. 1897. Rhodomelaceae. In: Die natürlichen Pflanzenfamilien nebst ihren Gattungen und wichtigeren Arten insbesondere den Nutzpflanzen unter Mitwirkung zahlreicher hervorragender Fachgelehrten, Teil 1, Abteilung 2 . (Engler, A. & Prantl, K. Eds), pp. 421-480. Leipzig: verlag von Wilhelm Engelmann.

Seagrief, S.C. 1984. A catalogue of South African green, brown and red marine algae. Memoirs of the Botanical Survey of South Africa 47: 1-72.

Setchell, W.A. 1943. Mastophora and the Mastophoreae: genus and subfamily of Corallinaceae. Proceedings of the National Academy of Science of the United States of America 29: 127-135.

Silva, P.C., Basson, P.W. & Moe, R.L. 1996. Catalogue of the benthic marine algae of the Indian Ocean. University of California Publications in Botany 79: 1-1259.

Sonder, O.G. 1846. Algae L. Agardh. In: Plantae Preissianae sive enumeratio plantarum quas in Australasia occidentali et meridionali-occidentali annis 1838-1841 collegit Ludovicus Preiss. (Lehmann, C. Eds) Vol. 2, pp. 148-160. Hamburgi [Hamburg]: sumptibus Meissneri.

Stegenga, H. 1984. A new species of Lomathamnion (Rhodophyta, Ceramiaceae) from South Africa. South African Journal of Botany 3: 351-355, 3 figs.

Stegenga, H. 1985. A note on Anotrichium tenue (C.Ag.) Näg. (Ceramiaceae, Rhodophyta) in Southern Africa. Acta Botanica Neerlandica 34 (2): 145-155.

Stegenga, H. 1986. The Ceramiaceae (excl. Ceramium) (Rhodophyta) of the South West Cape Province, South Africa. Bibliotheca Phycologica 74: 1-149, 1 table, 51 plates.

Stegenga H. 1988. Notes on Ceramiaceae (Rhodophyta) from the eastern Cape Province, South Africa I. New records and remarks on morphology. Blumea 33: 371-393.

Stegenga, H, Anderson, R.J & Bolton, J.J. 2000: Notes on Ceramiaceae (Rhodophyta) from the eastern Cape Province, South Africa. III. New records from the Tsitsikamma coastal park, with the description of Scageliopsis tsitsikammae. Blumea 45: 485-494.

Stegenga, H., Anderson, R.J. & Bolton, J.J. 2004. Aphanocladia ecorticata nov. sp. (Rhodophyta, Rhodomelaceae) from the South African south coast. Botanica Marina 47: 167-170.

Stegenga, H., Bolton, J.J. & Anderson, R.J. 1997. Seaweeds of the South African west coast. Contributions from the Bolus Herbarium 18: 655 pp.

Stegenga, H. & Kemperman, T.C.M. 1987. A new species ofHerposiphonia (Rhodomelaceae, Rhodophyta) from South Africa. Acta Botanica Neerlandica 36: 133-137, 7 figs.

Suhr, J.N. von 1834. Übersicht der algen, welche von Hrn. Ecklon an der südafrikanischen küste gefunden worden sind. Flora 17: 721-735, 737-743, Figs. 1-21, Plates I, II.

Suhr, J.N. von 1840. Beiträge zur Algenkunde. Flora 23: 257-265, 273-282, 289-298.

Taylor W.R. 1945. Pacific marine algae of the Allan Hancock Expeditions to the Galapagos Islands, Allan Hancock Pacific Expeditions 12: i-iv, 1-528, 3 figs, 100 pls.

Trevisan, V.B.A. 1875. Sulla fruttificazione delle Ceramiacee. Rendiconti del Reale Istituto Lombardo di Scienze e Lettere Ser. 2, 8: 377-384.

Williamson, C.J., Walker, R.H., Robba, L., Yesson, C., Russell, S., Irvine L.M. & Brodie, J. 2015. Toward resolution of species diversity and distribution in the calcified red algal genera Corallina and Ellisolandia (Corallinales, Rhodophyta). Phycologia 54: 2-11.

Wilson, S.M. & Kraft, G.T. 2000. Morphological and taxonomic studies of selected genera from the tribe Amansieae (Rhodomelaceae, Rhodophyta). Australian Systematic Botany 13: 325-372.

Woelkering, W.J., Harvey, A.S. & Reviers, B. de 2015. Jania pedunculata (Rhodophyta: Corallinaceae): Typification, nomenclature, and taxonomic status relative to J. crassa,J. verrucosa sensu Johansen & Womersley, and J. ungulata. Taxon 64(6): 1280-1293.

Womersley, H.B.S. 1979. Southern Australian species ofPolysiphonia Greville (Rhodophyta). Australian Journal of Botany 27: 459-528, 14 figs.

Womersley, H.B.S. 1996. The marine benthic flora of southern Australia - Part IIIB - Gracilariales, Rhodymeniales, Corallinales and Bonnemaisoniales . Vol. 5 pp. 1-392, 160 figs. Canberra & Adelaide: Australian Biological Resources Study & the State Herbarium of South Australia.

Womersley, H.B.S. 1998. The marine benthic flora of southern Australia - Part IIIC. Ceramiales - Ceramiaceae, Dasyaceae . pp. 535. Canberra & Adelaide: Australian Biological Resources Study & State Herbarium of South Australia.

Womersley, H.B.S. 2003. The marine benthic flora of southern Australia - Part IIID Ceramiales - Delesseriaceae, Sarcomeniaceae, Rhodomelaceae . pp. 533. Canberra & Adelaide: Australian Biological Resources Study & State Herbarium of South Australia.

Womersley, H.B.S. & Johansen, H.W. 1996. Subfamily Corallinoidea (Areschoug) Foslie 1908: 19. In: The marine benthic flora of southern Australia - Part IIIB - Gracilariales, Rhodymeniales, Corallinales and Bonnemaisoniales . (Womersley, H.B.S. Ed.), pp. 288-317. Adelaide & Canberra: Australian Biological Resources Study & the State Herbarium of South Australia.

Wynne, M.J. 1984. Notes on Herposiphonia (Rhodomelaceae, Rhodophyta) in South Africa, with a description of a new species. Cryptogamie, Algologie 5: 167-177, 12 figs.

Wynne, M.J. 1985. Two new species of Tayloriella (Rhodomelaceae, Rhodophyta) from the northeastern North Pacific. Journal of Phycology 21: 107-114.

Wynne, M.J. 1986. Report on a collection of benthic marine algae from the Namibian coast (southwestern Africa). Nova Hedwigia 43: 311-355.

Wynne, M.J. 2005. A check-list of benthic marine algae of the tropical and subtropical western Atlantic: second revision. Beihefte zur Nova Hedwigia 129: 1-152.

Wynne, M.J. 2017. Proposal of some nomenclatural adjustments. Notulae Algarum 21: 1-2.

Yoshida, T. (1998). Marine algae of Japan. pp. 25 + 1222. Tokyo: Uchida Rokakuho Publishing.

Yoon, H.S., Nelson, W., Lindstrom, S.C., Boo, S.M., Pueschel, C., Qiu, H., & Bhattacharya, D. 2017 Rhodophyta. In: Archibald, J., Simpson, A., Slamovits C. (eds) Handbook of the Protists. Springer, Cham.

Zuccarello, G.C. & West, J.A. 2006. Molecular phylogeny of the subfamily Bostrychioideae (Ceramiales, Rhodophyta):subsumingStictosiphonia and highlighting polyphyly in species of Bostrychia. Phycologia 45: 24-36.

GLOSSARY

Bisexual:

having both sexes.

Blade:

a flattened, leaf-like part of the thallus.

Calcar:

spur subtending a cystocarp.

Carpogonium (pl. carpogonia):

the female sex structure in red algae.

Carpospore:

a spore, usually diploid, produced in the carpogonium. In red algae, it grows into a free-living tetrasporophyte.

Cerata:

dorsal appendages on some opisthobranch mollusks (sea slugs) that contain diverticula of the digestive gland. Serve as gills.

Chloroplast:

a cell organelle specialized for photosynthesis, the production of carbohydrates from carbon dioxide, water in the presence of light energy.

Coenocytic:

referring to a multinucleate cell, the coenocyte, derived when the nucleus divides but the cytoplasm does not.

Conceptacle:

a fertile cavity, often with a pore.

Cortex:

tissue external to the medulla, often an outer covering, of a blade.

Cryptostomata:

minute cavities in the outer cortex of Fucales containing hairs.

Cystocarp:

a structure in the female gametophyte of red algae consisting of diploid carposporophyte surrounded by gametophytic tissue. It may be a pigmented bump with or without an ostiole.

Dichotomous:

branching in pairs.

Dioecious:

bearing male and female reproductive structures on separate individuals.

Diploid:

having a normal (double or 2n) set of chromosomes.

Discoid:

disk shaped. Usually referring to the shape of holdfasts.

Distichous:

arranged in two rows on opposite sides of an axis.

Distromatic:

having two layers of cells.

Gametangium (pl. gametangia):

a structure that produces gametes.

Euryhaline:

able to withstand a wide range of salinities.

Eurythermal:

able to withstand a wide range of temperatures.

Filamentous:

a row of cells arranged end to end forming a hair-like thallus.

Gamete:

a sexual cell, male or female (e.g., sperm and eggs).

Gametophyte:

the haploid and sexual phase in the life history of an alga; produces gametes.

Haploid:

having a single set of chromosomes - half the normal number (1n).

Herbivory:

feeding on plants.

Holdfast:

the structure that attaches the alga to its substratum.

Intercallary:

occurring anywhere along the thallus except at the apex.

Intergeniculum (pl. intergenticula): a

calcified segment between the uncalcified joints of coralline algae.

Isomorphic:

having the same shape; looking alike.

Lanceolate:

shaped like a lance; several times longer than wide.

Laminarin:

a polysaccharide carbohydrate energy storage product in Laminaria.

Meristem:

a region of rapidly dividing, undifferentiated cells; an area of growth.

Midrib:

the middle rib of a blade.

Monoecious:

bearing male and female reproductive structures on the same individual.

Monostromatic:

having one layer of cells.

Oogonium:

a female reproductive cell (gametangium) that produces one or more female gametes (eggs).

Ostiole:

a pore.

Ovate:

egg-shaped.

Papilla (pl. papillae):

small rounded or pimple-like projections on a surface

Pericentral:

surrounding central axial cells.

Pinnate:

having similar parts arrange on opposite sides of an axis, like a feather.

Plastid:

a pigmented cell organelle (e.g., a chloroplast which contains chlorophyll).

Pneumatocyst:

a gas bladder or float of brown algae.

Receptacle:

the inflated tip of a branch that holds conceptacles (e.g. the swollen tip of Fucus).

Rhizoid:

a unicellular or filamentous structure for attachment.

Rhizome:

a horizontal, shoot-producing stem growing within the substrate.

Saxicolus:

growing on rocks.

Spermatangium (pl. spermatangia):

a cell in red algae that produces a single, nonflagellated, male gamete (the spermatium).

Spore:

a motile or nonmotile, asexual reproductive structure.

Sporophyll:

the part of the alga, usually a blade, which bears sporangia, the structure that produces spores.

Sporophyte:

the diploid phase in the life history of the alga; produces spores.

Sorus (pl. sori):

a cluster of reproductive structures.

Stipe:

the stem-like part of the thallus between the holdfast and the blade(s).

Stolon:

a runner growing out of the base of the alga capable of producing offshoots.

Substratum:

the material (such as rock) on which the alga is growing (substrate).

Tetraspore:

a spore, grouped in fours, produced by tetrasporophytes

Tetrasporophyte:

a phase in the life history of red algae that produces tetraspores.

Tertiary:

referring to a third stage.

Thallus:

the body of the alga.

Uniseriate:

having a single row of cells.

Utricle:

the inflated part of Codium that contains plastids.

Vegetative:

not associated with reproductive cells or sexual reproductive capacity.

Zygote:

a fertilized egg cell.

INDEX TO GENERA AND SPECIES

FAMILY RHODOMELACEAE

Acanthophora spicifera

Aiolocolax pulchellus

Aphanocladia ecorticata

Bostrychia harveyi

Bostrychia intricata

Bostrychia moritziana

Bostrychia radicans

Bostrychia simpliciuscula

Bostrychia tangatensis

Bostrychia tenella

Chondria armata

Chondria capensis

Chondria dasyphylla

Chondria sp.

Colacopsis velutina

Dasyclonium incisum

Dasyclonium palmatifidum

Dictyomenia stephensonii

Hawaiia sp1.

Herposiphonia clavata

Herposiphonia didymosporangia

Herposiphonia falcata

Herposiphonia prorepens

Herposiphonia secunda

Herposiphonia secunda f. tenella

Janczewskia meridionalis

Laurencia alfredensis

Laurencia complanata

Laurencia cf corymbosa

Laurencia digitata

Laurencia flexuosa

Laurencia glomerata

Laurencia griseaviolacea

Laurencia multiclavata

Laurencia natalensis

Laurencia pumila

Laurencia pumila var. dehoopiensis

Lophosiphonia capensis

Lophosiponia reptabunda

Microcolax africanus

Onychocolax polysiphoniae

Ophidocladus simpliciusculus

Osmundaria serrata

Pachychaeta brachyarthra

Pachychaeta cryptoclada

Placophora binderi

Placophora monocarpa

Kentrophora natalensis

Neosiphonia sertularioides

Polysiphonia foetidissima

Polysiphonia incompta

Polysiphonia kowiensis

Polysiphonia namibiensis

Polysiphonia scopulorum

Polysiphonia sp.1

Polysiphonia sp.2

Polysiphonia sp.4

Polysiphonia subtilissima (note only)

Polyzonia elegans

Pterosiphonia cloiophylla

Pterosiphonia spinifera

Pterosiphonia stangerii

Pterosiphonia stegengae

Pterosiphonia sp indet.

Rhodomelopsis africana

Streblocladia corymbifera

Streblocladia tenuissima

Streblocladia sp1.

Symphyocladia marchantioides

Tayloriella tenebrosa

FAMILY SPYRIDIACEAE

Spyridia cupressina

Spyridia filamentosa

Spyridia horridula

Spyridia hypnoides

Spyridia plumosa

FAMILY WRANGELIACEAE

Anotrichium furcellatum

Anotrichium tenue

Dasyphila cryptocarpa

Griffithsia confervoides

Griffithsia subbiconica

Griffithsia sp.

Gymnothamnion elegans

Gymnothamnion elegans var. bisporum

Haloplegma duperreyi

Pleonosporium callicladum

Pleonosporium filicinum

Pleonosporium harveyanum

Shepleya elixithamnia

Spermothamnieae indet.

Spongoclonium caribaeum

Stegengaea capensis

Tiffaniella cymodoceae

Tiffaniella schmitziana

Vickersia baccata

Wrangelia purpurifera

FAMILY CORALLINACEAE

  SUB-FAMILY CORALLINOIDEAE (articulated, geniculate taxa)

Amphiroa anceps

Amphiroa beauvoisii

Amphiroa bowerbankii

Amphiroa capensis

Amphiroa ephedraea

Amphiroa rigida

Arthrocardia carinata

Arthrocardia corymbosa

Arthrocardia duthieae

Arthrocardia flabellata

Arthrocardia palmata

Corallina berteroi

Corallina sp.1

Jania adhaerens

Jania capillacea

Jania cultrata

Jania prolifera

Jania sagittata

Jania subulata

Jania verrucosa

  SUB-FAMILY MASTOPHOROIDEAE

Metamastophora flabellata

FAMILY HAPALIDACAE

Choreonema thuretii

The Authors

From left: Rob Anderson, Herre Stegenga and John Bolton.

Brief biographies

Rob Anderson completed a PhD at the University of Cape Town in 1982, just after joining the Seaweed Unit in the SA Government fisheries department. Although much of his work involved commercial seaweed resources, he maintained a strong interest and has published in many aspects of seaweed biology and systematics. He has collaborated extensively with John Bolton, Herre Stegenga and others. Recently retired, he continues to surf, dive and enjoy the ocean.

Herre Stegenga completed his Ph D ("doctoraat") in 1979 at the Free University of Amsterdam. He published a Flora of the Dutch Seaweeds in 1983 (with Ivo Mol) and spent the next ten years mainly in South Africa (University of Cape Town, Rhodes University in Grahamstown), resulting in the publication of the Seaweeds of the South African West Coast (Stegenga, Bolton & Anderson 1997). After 1992 he revisited the RSA several times to collect material from the South Coast. Retired in 2012, he is still active in western European seaweed identification.

John Bolton is Emeritus Professor and Senior Research Scholar at the University of Cape Town, where he taught all aspects of phycology (the study of algae) for 35 years. His research interests include the diversity and biogeography of seaweeds, seaweed use and aquaculture, and the integrated aquaculture of seaweeds with marine animals. He is a former President of the International Phycological Society, and was awarded the Gilchrist Memorial Medal in 2017 in recognition of his contribution to South African marine science.

Acknowledgments

We are deeply indebted to Professor Michael Guiry and his colleagues who built and continue to maintain the incomparable algal website AlgaeBase.org – without it we would never have attempted this guide.

Chris and Derek
Our heartfelt thanks to Chris Boothroyd and
Derek Kemp for their enthusiastic and invaluable
technical help throughout the project.

We thank our colleagues and post-graduate students whose knowledge has been of enormous help, especially, Olivier De Clerck, Frederik Leliaert, Heroen Verbruggen and Eric Coppejans (Ghent University, Belgium), Enrico Tronchin (UCT) and others.

This work was funded from several sources over many years. FRD/NRF Post-doctoral bursaries sustained Herre Stegenga at Rhodes University and at UCT when he made many collections of specimens and microscope slides. DAFF (Department of Agriculture, Forestry and Fisheries) supported the participation of Anderson, Kemp and Boothroyd. SANPAD (South Africa Netherlands research Programme on Alternative Development) grants allowed us to train students and improve our collections from the south coast between 2001 and 2004. Various grants from NRF, UCT and DAFF all contributed through various projects. Most importantly, NRF funding of the SeaKeys Programme supported the development of this website. SANPARKS allowed us access to marine parks where important records were found. Finally, we thank the curators of the BOL and GRA herbaria for access to collections.

Colophon

Published by Seaweed Research Unit, Department of Biological Sciences, University of Cape Town and the Department of Agriculture, Forestry and Fisheries of South Africa.
Cape Town, South Africa

Typesetting: Seaweed Research Unit, Department of Biological Sciences, University of Cape Town, Rondebosch 7701, South Africa.