Seaweeds of the South African South Coast

Book 3: Phylum Rhodophyta (Red Seaweeds)
Order Bangiales to Order Gracilariales

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

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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 Bangiales

Family Bangiaceae

Genus Porphyra C. Agardh

Gametophyte thalli bladed, membranous and monostromatic. Blades lanceolate, rosette (umbilicate) or orbicular and ranging in size from a few mm to more than a metre (only to about 30 cm on the south coast). Gametophyte phase alternating with a conchocelis-phase: a shell-boring microscopic stage that germinates into filaments. Porphyra can be monoecious, dioecious or androdioecious (hermaphrodites) and is able to reproduce sexually or asexually (in both the bladed and conchocelis-phase), via various types of spore. Modes of reproduction may vary among species and may even differ within a single species found in different localities.

Porphyra is widely distributed in temperate regions worldwide and is one of 15 genera belonging to the order Bangiales. This genus previously contained species cultivated for the multibillion dollar (USD) nori industry, but these species have been reassigned to another genus following a molecular taxonomic revision of the Bangiales (Sutherland et al., 2011). In fact, a large majority of species that were originally assigned to the genus Porphyra are now assigned to new or resurrected genera.

Porphyra currently consists of a number of species that are based on morphological species concepts (Guiry MD, in Guiry & Guiry, 2017), most of which remain to be assessed using molecular data. P. capensis Kützing 1843 is one of the species of Porphyra that has been verified using morphological, life-history and molecular data. This morphologically variably and widespread spread was shown to comprise of multiple molecular species (Jones et al., 2004; Reddy et al., 2018). These molecular species can be regarded as two endemic cryptic species groups. The first is a species-rich and genetically diverse P. capensis complex comprising eight morphologically cryptic and largely sympatric species along the west coast of South Africa (Benguela Marine Province). The second is a pair of cryptic sibling species along the south coast of South Africa (Agulhas Marine Province) that are morphologically distinct from the P. capensis complex on the west coast. The more widely distributed and abundant of the cryptic species pair along the south coast of South Africa is in the process of being described as a new species (Reddy et al., in prep).

Although the two cryptic species groups are morphologically distinct from one another, species within each of the groups are not.

Key to south coast species

1a Blade thickness greater than 60 µm, 1-2 chloroplast(s) per cell, cells appear ovoid in cross section of the thallus, trichogynes absent

P. capensis complex (Cryptic species complex)

1b Blade thickness less than 60 µm, 1 chloroplast per cell, cells appear elliptical in cross section of the thallus, trichogynes present

P. species duo (Cryptic species pair)

Order Bangiales

Family Bangiaceae

Porphyra capensis (P. capensis complex – see note)

Plants membranous, varying from light yellow through dark red /purple to almost black, varying in size from a few cm to a couple of meters. Thallus varying shape from orbicular to elongate; blade usually 100-150 µm thick. Cells in surface view rather irregularly arranged, rounded, 8-15 µm in diameter. Cells in cross section elongated, up to four times as long as broad, containing 1-2 stellate chloroplasts, each with a pyrenoid. Plants dioecious, with spermatangial areas visible around margins as pale or yellow band and carposporangial areas a darker red than vegetative areas. Reproductive cells a similar shape to vegetative cells. Mature spermatangia containing up to 24 tiers of spermatia; carposporangia containing about 32 carpospores in 8 tiers.

Collections, ecology and regional distribution

This complex is almost completely restricted to the west coast, with relatively few unequivocal records from the south coast: (Plettenberg, Knysa and Cape St. Francis). Usually in the mid to upper-eulittoral zones. Thalli high on the shore tend to become pale to yellow.

World distribution: recorded from other countries, but recent molecular work shows that there are in fact many species involved.

Type locality: Table Bay, Cape of Good Hope (Silva et al., 1996), but it is not known which of the many species in this complex the type represents (see note).

Note: The entity previously known as P. capensis Kützing 1843 has been shown to comprise multiple molecular species (Jones et al., 2004; Reddy et al., 2018) and the type cannot be unequivocally linked to any of them. The species-rich and genetically diverse P. capensis complex comprises eight morphologically cryptic and largely sympatric species along the west coast of South Africa (MM Reddy, pers. comm.)

Porphyra capensis (west coast specimens). 1. Habit of umbilicate plant. 2. Cellular arrangement (surface view). 3. Section of vegetative thallus. 4. Section of sprematangial area. 5. Section of carposporangial area. Illustrations from Stegenga et al. (1997).

Porphyra capensis (complex). Typical low-shore population on the west coast, among patches of the green Ulva sp. Photo M.M. Reddy.

Porphyra capensis (complex), showing the range of morphological variation among members of this species complex (west coast specimens). Scale bars = 25 mm. Illustration provided by M.M. Reddy.

Order Bangiales

Family Bangiaceae

Porphyra sp. 1 nov.

Gametophytes comprising deeply laciniate rosette thalli that may appear star-shaped, consisting of multiple lanceolate to orbicular blades with entire margins attached to a central discoid holdfast. Thalli generally small (commonly around 60 mm in diameter) but may reach up to 300 mm in diameter. Fresh specimens light olive green to light pinkish-brown, progressively becoming more green or golden brown when dried and adheres poorly to herbarium paper. Blades monostromatic, 60-65 (-75) µm thick. In cross section of the thallus, vegetative cells 25-40 (-60) µm high, commonly around 30 µm, rectangular to ellipsoid, only slightly longer than wide. In surface view, vegetative and reproductive cells evenly distributed in longitudinal rows with large spaces between neighbouring cells. Spermatia small, lanceolate and bright yellow. Zygotosporangia large, ovate and deep maroon. Female reproductive cells with recognisable bipolar trichogynes. Spermatia arranged in 8 rows, in two columns, in pairs (16-32 tiers). Zygotosporangia arranged in four columns (32-64 tiers). Both spermatia and zygotosporangia observed in fertile plants suggesting a monocieous habit. Spermatia and zygotosporangia are not intermingled as in South African Pyropia species.

Collections, ecology and regional distribution

Recorded from Mossel Bay to the Port Alfred area (27-39). Attached to rock along the mid to high shore, occasionally on the low shore. Gametophytes are present for a few weeks at a time but can be found throughout the year. This species is endemic to the South African coast and was found from Port Alfred to Mossel Bay during the winter but may extend eastwards to Arniston during the austral spring and summer (T.S. Dlaza; unpublished data).

Type locality: Port Elizabeth (MM Reddy, publication in prep.)

Note 1. This species was previously misidentified as a dwarf form of P. capensis (Graves 1969), and is sparsely distributed along the South African south coast. At Plettenberg Bay, it was abundant and thalli were larger, darker and thicker than at other sites. Species belonging to the P. capensis complex and P. sp. 1 nov. have been found to co-occur at this site. Porphyra sp. nov. differs genetically from other species belonging to the P. capensis complex by 4-5% in the cox1 gene, 2-3% in the rbcL gene and 1-2% in the nSSU gene (M Reddy, pers. comm.). This entity was denoted as Porphyra ZPP by Jones et al. (2004).

Note 2: There is a second south coast entity, that emerges as a molecular sister species to Porphyra sp. nov.(MM Reddy, specimens EL1-7, DKG5, pers. comm.). However, the two are morphologically indistinguishable. This sister species has been recorded (at mid-tide level) only from two localities that are about 1000 km apart: East London, and De Kelders. Interestingly, these two localities lie just outside the present distribution range of Porphyra sp. 1 nov.

Porphyra sp nov, Cape St Francis. (Lens cap 50 mm in diameter).

Porphyra sp nov, young thalli, Morgan Bay.

Figures a-k. Porphyra sp. nov. Morphological and anatomical characters. a-c, h) Overall thallus morphology, d-e) Surface view showing vegetative cells, f) Surface view showing reproductive cells, g) Cross section of thallus showing vegetative cells, i) Cross section of thallus showing immature and developing reproductive cells, j) Zygotosporania in cross section and k) Spermatangia in cross section. Illustrations by M.M Reddy.

Order Stylonematales

Family Stylonemataceae

Stylonema Reinsch

Thalli minute, consisting of uniseriate or multiseriate filaments of cells in a mucilaginous sheath; filaments branched, unbranched or forming a monostromatic blade. Single stellate chloroplast with central pyrenoid in each cell. Growth diffuse or intercalary but sometimes apical in first stages of development. Attached by basal cell, which may be enlarged. Sexual reproduction unknown, asexual reproduction by transformation of vegetative cells into monosporangia that each release a single, naked monospore. Thalli usually epiphytic or epizoic. The genus is widespread is widespread in temperate and tropical seas; three species are currently recognised, of which two have been recorded from the SA south coast.

Stylonema alsidii (Zanardini) Drew 1956: 72

Plants, epiphytic, red, up to 10 mm tall, irregularly branched. Holdfast a simple undifferentiated basal cell. Thalli of uniseriate filaments of cells, becoming multiseriate in older parts, embedded in a thick, clear, mucilaginous sheath; about 40 µm in diameter basally narrowing to about 15 µm at apices. Cells 10-14 µm in diameter, 1-3 times as broad as long, containing a single stellate chloroplast and a central pyrenoid. Reproduction by transformation of vegetative cells to produce monospores; sexual reproduction unknown.

Collections, ecology and regional distribution

Epiphytic on various algae in rock pools and the sublittoral fringe. Recorded from Saldanha Bay on the west coast to northern Kwazulu-Natal (13-58).

World distribution: Worldwide in temperate and tropical seas (Guiry & Guiry 2012); in southern Africa also known from Namibia (Rull Lluch 2002) and Mozambique and Tanzania (Silva et al. 1996).

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

Notes: 1. Previously known as Goniotrichum alsidii (Zanardini) Howe or G. elegans (Chauvin) Zanardini (see Wynne 1985).

Note: Stylonema cornu-cervi Reinsch (as Goniotrichum cornu-cervi (Reinsch) Hauck was recorded once from Hluleka, Eastern Cape, by Bolton & Stegenga (1987). The branches in this species are uniseriate at the base and apex, but otherwise 2-5 (or more) cells wide. It is also recorded from northern Namibia, close to the Angolan border (Rull Lluch, 2002).

Stylonema alsidii (base uppermost), showing uniseriate branches.

Stylonema alsidii, detail of cells and branching.

Stylonema alsidii. Microscopic habit. 2. Detail showing development of multiseriate thallus (reproduced from Stegenga et al. 1997).

Order Erythropeltidales

Family Erythrotrichiaceae

Genus Erythrotrichia Areschoug 1850: 435

Thalli filamentous, unbranched or sparingly branched proximally; uniseriate proximally, distally either becoming multiseriate or forming monostromatic blades. Attached by basal cells, sometimes with rhizoidal outgrowths that penetrate the host. Early growth may be apical but becomes diffuse or intercalary. Chloroplast stellate, central, with single pyrenoid. Asexual reproduction via monospores. Sexual plants monoecious, also producing monospores.

The distributions of southern African Erythrotrichia species are discussed by Stegenga et al (2001).

Key to south acoast species

1 a Mature plants foliaceaous, up to 3 mm wide

Erythrotrichia platyphylla

1 b Mature plants filamentous, less than 50 µm wide

2

2 a Thallus of single unbranched filament (uniseriate basally becoming multiseriate) arising from basal disc

Erythrotrichia bertholdii

2 b Thallus of branched uniseriate filament without basal disc

Erythrotrichia welwitschii

Order Erythropeltidales

Family Erythrotrichiaceae

Erythrotrichia bertholdii  Batters 1900: 375

Plants comprising a single erect filament arising from a small multicellular basal disc. Erect filament a few mm to (rarely) a few cm long, uniseriate becoming multiseriate distally; uniseriate region 25-30 µm in diameter. Monosporangia produced by unequal division of cells, after monospore release the remaining sickle-shaped cell grows back into its original shape.

Collections, ecology and regional distribution

Epiphytic on larger algae. Recorded along the entire SA west coast and as far east as Port Alfred (1-39), but may be more widespread as it is often overlooked because it is small.

World distribution: Adriatic and north-eastern Atlantic coasts (Guiry & Guiry 2011).

Type locality

Scilly Isles, England (Brodie & Irvine 2003).

Note: Stegenga et al. (1997) record Erythrotrichia carnea (Dillwyn) J. Agardh from the west coast as “remaining uniseriate or becoming multiseriate distally”. However, Brodie and Irvine (2003) separate uniseriate and multiseriate species, including E. carnea among the former species. All our south coast specimens become multiseriate (as do at least some west coast specimens), and are morphologically most similar to Erythrotrichi bertholdii.

Erythrotrichia bertholdii, dense growth of individual thalli.

Erythrotrichia bertholdii, young thalli developing from basal discs- epiphytic on Polysiphonia.

Erythrotrichia bertholdii; monosporangia.

Order Erythropeltidales

Family Erythrotrichiaceae

Erythrotrichia platyphylla Stegenga, Engledow, Bolton & Anderson 2001: 369-372, figs 2-10

 Plants solitary; juveniles filamentous, uniseriate; mature plants foliaceous, monostromatic, linear to broadly lanceaolate or cuneate, up to 8 mm tall and to 3 mm wide. Stipe uniseriate, about 30 µm diameter, often only 4-5 cells long; holdfast formed from basal cell which develops outgrowths into host tissue. Cells in young blades in longitudinal rows, in mature blades un-ordered, angular, sometimes rather elongated, 10-20 x 7.5-10 µm; thallus 20-25 µm thick. Single stellate chloroplast per cell with single central pyrenoid. Monosporangia formed by unequal division of cells over most of thallus surface; monospores hemispherical, 10-12 µm in diameter leaving small, rather flattened remainder of sporangial mother cell.

Collections, ecology and regional distribution

Epiphytic on large brown algae (Anthophycus, Sargassum, Ecklonia radiata). Recorded from Port Elizabeth to Kei Mouth (36-43).

World distribution: a South African endemic.

Type locality: Morgan Bay, Eastern Cape Province, South Africa (Stegenga et al. 2001).

Note: Stegenga et al. (2001) provide a detailed discussion of possible relationships between this and similar species.

Erythrotrichia platyphylla, two thalli, largest ca. 1 mm wide.

Erythrotrichia platyphylla, showing stipitate base of upright.

Erythrotrichia platyphylla, detail of cells in surface view.

Order Erythropeltidales

Family Erythrotrichiaceae

Genus Erythrotrichia

Erythrotrichia welwitschii (Ruprecht) Batters 1902: 55

Thallus with branched uniseriate erect filament several mm long arising from an endophytic base without a disc; branching only in proximal to mid-region of thallus. Filaments uniformly 20-25 µm in diameter, cells longer than broad in proximal regions, usually broader than long in distal regions. Monospores formed by unequal division of vegetative cells. 

Collections, ecology and regional distribution 

Found as an epi- or endophyte on Ralfsia and some other brown algae. Recorded from Cape Point to Double Mouth, near Morgan Bay (17-43).

World distribution

Warm temperate European Atlantic, Namibia, Morocco, also recorded from California and Oregon (AlgaeBase).

Notes

Further information on South African material of this species is found in Papenfuss (1952) and Stegenga et al (1997).

An unnamed, similar species of Erythrotrichia (described from the west coast by Stegenga et al 1997: 218) has been found as far east as Keiskamma Point (Stegenga et al 2001). This entity has an endophytic base and emergent branched filament up to 3 mm long: it differs from welwitschii in that its multiseriate distal region becomes tubular and up to 100 µm in diameter.

Erythrotrichia welwitschii attached to fragment og brown algal host tissue

Erythrotrichia welwitschii,  detail of uniseriate upright filaments (fresh material), Nature’s Valley)

Erythrotrichia welwitschii, showing microscopic habit on the right and detail of a filament with monosporagnia on the left. This illustration reproduced from Stegenga et al. 1997.

Order Erythropeltidales

Family Erythrotrichiaceae

Genus Membranella Hollenberg & Abbott

Note: The type species of this genus, M. nitens, has been shown to belong to the genus Smithora (West & Zuccarello 2009), so that our species should probably also be referred to Smithora.

Membranella africana Stegenga, Bolton & Anderson 1997: 220

Plants with one to several shortly stipitate blades arising from a multicellular holdfast; cells of holdfast and stipe elongated but without rhizoids. Stipe tubular, multiseriate; blades pale red, round to ovate, monostromatic, up to 10 mm tall, about 15 µm thick; cells rounded, 5-8 µm in diameter, with central stellate chloroplast and central pyrenoid. Reproduction by monosporangia formed in patches in upper half of blade by unequal division of vegetative cells.

Collections, ecology and regional distribution

Epiphytic on various seaweeds in lower eulittoral and shallow sublittoral zones. Recorded from Cape Point to Kei Mouth (17-43).

World distribution: South African endemic.

Type locality: Cape of Good Hope (just west of Cape Point), South Africa (Stegenga et al. 1997).

Notes: 1. Plants are very similar to small Porphyra thalli among which they are sometimes found, but they lack “true rhizoidal cells in the basal structure” (Stegenga et al. 1997). They are also superficially similar to Erythrotrichia platyphylla but have a multiseriate stipe (Stegenga et al. 2001). 2. The only other recognised species of Membranella, and the type of the genus, M. nitens, was shown by the DNA study of West & Zuccarello (2009) to be conspecific with the larger species Smithora naiadum. The South African M. africana therefore requires molecular examination but should probably be transferred to Smithora: interestingly, that genus has not been recorded here.

Membranella africana, microscope slide of whole thallus.

Membranella africana, base of thallus.

Membranella africana, monosporic tissue on left.

Membranella africana, monosporic tissue visible on left as patchy areas.

Membranella africana, 1. Habit of fertile plant. 2. Base of plant (note cylindrical “stipe”). 3. Detail of thallus edge, with formation of monospores. Reproduced from Stegenga et al. (1997).

Order Erythropeltidales

Family Erythrotrichiaceae

Porphyrostromium boryanum (Montagne) P.C. Silva in Silva, Basson & Moe 1996: 914

Plants with several erect, unbranched axes up to 5 mm long arising from a multicellular, monostromatic basal disc; erect axes initially uniseriate, becoming multiseriate (several cells wide), ribbon-shaped and up to 100 µm wide. Cells somewhat squarish in surface view, 5-10 µm in diameter, lying in transverse and longitudinal rows. Monosporangia formed by unequal divisions of the cells in the multiseriate parts of the thallus.

Collections, ecology and regional distribution

Epiphytic on larger algae. Recorded from Yzerfontain on the west coast to Mkambati in Transkei (14-47).

World distribution: in southern Africa also recorded from Namibia (Rull Lluch, 2002; as Erythrotrichia boryana; Stegenga et al. 2001), but widespread in temperate seas (Guiry & Guiry, 2012).

Type locality: Algeria (Ardré, 1970).

Porphyrostromium boryanum (stained slide material).

Porphyrostromium boryanum, microscopic habit, basal disc in section Reproduced from Stegenga et al. (1997)(as Erythrotrichia boryana).

Order Erythropeltidales

Family Erythrotrichiaceae

Sahlingia subintegra (Rosenvinge) Kornmann 1989: 227, figs1, 6-13

Plants minute, pale red, monostromatic discs with rather smooth margins; up to a few mm in diameter. Marginal cells of disc elongated, often forked, to 25 µm long and about 10 µm wide; inner cells polygonal, about 10 µm diameter; all cells with single central or parietal chloroplast with one pyrenoid. Monosporangia formed by unequal divisions of central cells of thallus.

Collections, ecology and regional distribution

Epiphytic and epizoic on a variety of algae and animals. Recorded from False Bay to Mkambati area of Transkei (114-47) but probably more widespread and overlooked on account of its size.

World distribution: widespread in temperate and tropical waters; in southern Africa known from Namibia (Guiry & Guiry 2012).

Type locality: Skagerak, Denmark (Silva et al. 1996).

Note: Stegenga et al. (2001) point out that this species can be confused with basal discs of Porphyrostromium boryanum , in which monosporangia can form (in addition to those on their uprights).

Sahlingia subintegra, visible as disc on host tissue, centre of figure.

Sahlingia subintegra, side view of disc on host tissue.

Sahlingia subintegra, young disc in isolation, with some of host tissue below.

Sahlingia subintegra, disc growing over part of internode of Ceramium host.

Sahlingia subintegra.  Various stages in development of the thallus, in 4 and 5 producing monospores. (Reproduced from Stegenga et al., 1997; as Erythrocladia subintegra).

Order Hildenbrandiales

Family Hildenbrandiaceae

Hildenbrandia Nardo

Thallus crustose, closely adherent, firm, not calcified. Structure of tightly adherent but rather indistinct basal layer, without rhizoids, each cell producing erect filament of small cuboidal cells of uniform size. Sexual reproduction unknown. Tetrasporangia zonately or irregularly divided, in sunken, ostiolate conceptacles, with or without paraphyses.

Key to species

1a. Crusts dark red, thick (to a few mm), with rough surface, easily detached in the middle

Hildenbrandia
lecanellierii

1b. Crusts red or reddish-brown, thin (usually < 100 µm) smooth and firmly attached throughout

Hildenbrandia
rubra

Order Hildenbrandiales

Family Hildenbrandiaceae

Hildenbrandia lecanellierii Hariot 1887: 74, fig. 6

Plants crustose, dark red or brownish-red, several cm (or more) in diameter. Margins smooth but central (older) parts becoming rugose or tuberculate and several mm thick, often with sand grains included in the thallus; older parts easily removed from the substratum. Cells throughout the thallus of rather uniform size (3-5 µm diameter), rectangular, slightly longer than broad, arranged in vertical rows, several minute chloroplasts per cell. Tetrasporangial conceptacles ranging in shape (possibly with age) from shallow to globose to deeper depressions, about 80 µm in diameter and up to 150 µm deep; tetrasporangia regularly zonately divided, up to 40 x 12 µm in size.

Collections, ecology and regional distribution

Recorded from the Orange River to the Port Elizabeth area (1-37) but very seldom collected and may be more widespread. Epilithic, very common throughout the eulittoral zone, especially where water is held in crevices and hollows.

World distribution: Australia, New Zealand, Antarctica and some sub-Antarctic islands, Chile, Tierra del Fuego, Falkland Islands (Guiry & Guiry 2013).

Syntype localities: Fuegia and various in Strait of Magellan and Tierra del Fuego (Silva et al. 1996).

Note: In South Africa this entity was formerly known as Hildenbrandia pachythallos Dickinson ined. (Stephenson 1948) but was never formally described.

Hildenbrandia lecanellierii, in a rock pool at Cape St Francis. Cushion star about 20 mm diameter.

Hildenbrandia lecanellierii, section of tetrasporangial receptacle. Reproduced from Stegenga et al. (1997).

Order Hildenbrandiales

Family Hildenbrandiaceae

Hildenbrandia rubra (Sommerfelt) Meneghini 1841:426

Plants red to reddish-brown, crustose, smooth, forming large expanses. Thallus very thin (up to about 100 µm); cells of regular size (4-6 µm diameter), slightly longer than broad, in regular vertical rows, single chloroplast per cell. Tetrasporangial conceptacles subspherical, shallow with wide opening, up to about 100 µm diameter and 50 µm deep. Tetrasporangia up to 20 x 10 µm, division irregular zonate to cruciate.

Collections, ecology and regional distribution

Recorded from Namibia (Rull Lluch 2002), along the whole west and south coasts as far as Durban (1-51), also in Tanzania. Epilithic, very common in the littoral zone and apparently tolerant of wide range of temperatures and salinities. Seldom collected because of its thin, crustose habit.

World distribution: Almost worldwide, under several names including H. rosea Kützing and H. prototypus Nardo (Stegenga et al. 1997, Guiry & Guiry 2013).

Type locality: Norway (Guiry & Guiry 2013).

Hildenbrandia rubra in rock pool. Patch of encrusting coralline about 1 cm in diameter.

Hildenbrandia rubra 1-2, sections of tetrasporangial conceptacles. Reproduced from Stegenga et al. (1997).

Order Acrochaetiales

Family Acrochaetiaceae

Genus Acrochaetium Naegeli

Description from Stegenga et al. (1997): “Plants filamentous. Cells with a central stellate chloroplast and a central pyrenoid. Unicellular hairs occurring frequently. Life history triphasic, heteromorphic. Gametophytes with a single basal cell and one to six erect axes; tetrasporophytes with a multicellular base originating from a septately germinated spore, and with several erect axes.

In the field it is often difficult to recognise the different generations as belonging to the same life history, and in the past they have received different names. We have synonymised such “species” that have been shown to belong to the same life history when grown in culture.”

Almost 200 species are recognised worldwide (Guiry & Guiry 2014), among which 6 are recorded from the south coast of South Africa.

Note: Stegenga (1985) published a detailed account of South African Acrochaetiaceae, including most of the Acrochaetium species covered here. In that account and in Stegenga et al (1997) the genera Audouinella and Colaconema were treated as members of the Acrochaetiaceae, but the molecular study of Harper & Saunders (2002) subsequently erected the Order Colaconematales and Family Colaconemataceae to accommodate both these genera in the genus Colaconema.

Acrochaetium is distinguished from the superficially similar genus Colaconema by having a single axial stellate chloroplast per cell with one central pyrenoid.

Key to species

1a. Thalli almost completely endophytic, only reproductive cells protruding from the host; pattern of spore germination usually not detectable

A. brebneri

1b. Thalli mainly epiphytic; in young plants a typical septate pattern of spore germination is detectable (in the tetrasporophyte; gametophytes with a unicellular base)

2

2a. Thalli minute, erect filaments up to 6 cells long; to 6 µm in diameter

A. reductum

2b. Mature erect thalli more than 6 cells long, filaments 7-12 µm in diameter

3

3a. Monosporangia in terminal or lateral-secund, catenate series of 2-4

A. catenulatum

3b. Monosporangia usually single; secund, lateral or terminal

4

4a. Cells in middle of erect axes 7-7.5 µm in diameter; septation pattern of germinating spore 4-celled

A. hlulekaense

4b. Cells in middle of erect axes 8-10 µm in diameter; septation pattern of germinating spore either 2- or 3-celled

5

5a. Monosporangia 19-22 µm long; septation pattern of germinating spore 3-celled; cells in middle of erect axes 8-10 µm in diameter

A. tenuissimum

5b. Monosporangia less than 15 µm long; septation pattern of germinating spore 2-celled

A. moniliforme

Order Acrochaetiales

Family Acrochaetiaceae

Acrochaetium brebneri (Batters) G. Hamel 1928: 185

Plants largely endophytic, differentiated into long irregularly branched prostrate filaments running parallel to the host’s surface, and several shorter ‘erect’ filaments bearing the reproductive structures, the latter often the only emergent parts. Cells 5-10 µm in diameter, in the long filaments up to 35 µm long, shorter in the erect filaments. Monosporangia terminal on erect filaments or sessile on superficial prostrate filaments, 13-25 x 8-10 µm. Spermatangia in corymbose clusters, carpogonia sessile. Carposporophytes comparatively large and rather loosely filamentous.

Collections, ecology and regional distribution

Recorded from False Bay to the Port Alfred area (17-39). Endophytic in various larger seaweeds.

World distribution: Western Europe, but may be more widely distributed and recorded under various names (Stegenga et al. 1997).

Type locality: Rennie Rocks, Plymouth, Devon, England (Yoo & Lee 1979 in Guiry & Guiry 2014).

Notes: see Stegenga (1985) for further details on this and other South African Acrochaetiaceae.

Acrochaetium brebneri. 1. Microscopic habit, with monosporangia. 2. Spermatangia-bearing erect axis. (Illustrations reproduced from Stegenga et al. 1997).

Order Acrochaetiales

Family Acrochaetiaceae

Acrochaetium catenulatum M.A.Howe 1914: 84, pl. 31: figs 12-18

Plants minute, rarely over a few hundred µm high. Gametophytes with a unicellular base and one to three erect filaments. Tetrasporophytes with a multicellular filamentous base developing from a septately germinated spore; septation pattern typically two-celled. In both generations erect filaments arcuate, with secund laterals and/or monosporangial series . Filaments 7-8 µm in diameter at maximum, tapering towards the apex. Cells barrel-shaped, somewhat shorter to somewhat longer than broad. Monosporangia in terminal or lateral catenate series of 2-4: sporangia 6-8.5 (-12.5) x 5-7 µm.

Collections, ecology and regional distribution

Recorded from the Orange River to the Port Alfred area (1-39). On various larger algae; usually only the tetrasporophyte is found; fairly common in the lower eulittoral zone and below.

World distribution: Widely distributed in temperate seas (Stegenga et al. 1997).

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

Notes: Stegenga (1985) and Stegenga et al. (1997) considered that Acrochaetium densum and A. catenulatum were phases in the same life history – the latter name takes precedence. See Stegenga (1985) for further details on this and other South African Acrochaetiaceae.

Acrochaetium catenulatum (tetrasporophyte). 1. Basal system (from culture). 2. Erect axis with monosporangia. (Illustrations reproduced from Stegenga et al. 1997)

Order Acrochaetiales

Family Acrochaetiaceae

Acrochaetium hlulekaense Stegenga 1985: 297, 300 fig. 6

Plants comprising pseudoparenchymatous base bearing many upright axes. Plate-like base up to 150 µm in diameter, formed by adjacently-joined, branching filaments, cells ca 5 µm in diameter, slightly longer than broad. Erect filament arising from any cells of the basal plate, oldest filaments in the centre, up to 200 µm tall, with sparse indeterminate laterals. Cells in mid to distal parts of erect filaments 7-7.5 µm in diameter, narrowing to 5-6 µm near the base; 1-2 times as long as broad. Cells with one central stellate chloroplast and one central pyrenoid. Monosporangia on erect filaments, in second rows, sessile or pedicellate, ca 8 X 7-7.5 µm. No other reproductive structures seen.

Collections, ecology and regional distribution

Recorded from Tsitsikamma to Mntafufu, Transkei (32-45). Epiphytic on various Codium species, mainly C. platylobium.

World distribution: South African endemic.

Type locality: Hluleka, Eastern Cape, South Africa (Stegenga 1985).

Acrochaetium hlulekaense. Habit, on utricle of Codium. (Re-drawn from Stegenga 1985, Fig 6).

Acrochaetium hlulekaense. 1. Detail showing chloroplasts in vegetative cells and monosporangia. 2-7. Germlings (plants from the type specimens). (Re-drawn from Stegenga 1985, Fig 6).

Order Acrochaetiales

Family Acrochaetiaceae

Acrochaetium moniliforme (Rosenvinge) Børgesen 1915: 22

Plants rarely over a few hundred µm tall. Gametophytes with a unicellular base and 1-3 erect axes. Tetrasporophytes with a multicellular filamentous base originating from a septately germinated spore; septation pattern typically two-celled. Erect axes in both generations arcuate, with a secund series of laterals, 8-10 (-12) µm in diameter, tapering towards the apex. Cells barrel-shaped, slightly shorter to slightly longer than broad. Monosporangia terminal or lateral on main axis and main branches, single, ovate, 8-10 x 5-7 µm.

Collections, ecology and regional distribution

Recorded from False Bay to Hluleka (17 – 45), epiphytic on various algae (Stegenga et al. 1997).

World distribution: various tropical and warm temperate localities worldwide (Guiry & Guiry 2014).

Type locality: “various in Denmark” (Silva et al. 1996).

Note: tetrasporophytic phase not recorded from South Africa (Stegenga et al. 1997). See also Stegenga (1985) for further details.

Acrochaetium moniliforme, gametophytes (Illustrations reproduced from Stegenga et al. 1997).

Order Acrochaetiales

Family Acrochaetiaceae

Acrochaetium reductum (Rosenvinge) G.Hamel 1927: 95

Plants minute, erect parts usually under 30 µm tall. Gametophytes with a unicellular base and one to three erect filaments; axes up to ca. 5 cells long. Tetrasporophytes with an extensive multicellular filamentous basal system originating from a septately germinated spore; septation pattern typically two-celled. Erect filament very short, usually no more than three cells, often sporangia sessile on the prostrate filaments. Erect filaments 4-6 µm in diameter, cells about as long as broad. Monosporangia terminal or lateral, or sessile on the prostrate filaments, 5-8 x 4-5 µm.

Collections, ecology and regional distribution

Recorded from False Bay to Haga Haga (17-42). Epiphytic on various algae in the lower eulittoral and tide pools.

World distribution: Also recorded from Namibia, Europe and Iceland (Guiry & Guiry 2014).

Type locality: “Kattegat, between Sweden and Denmark Type: C?” (Athanasiadis 1996, cited in Guiry & Guiry 2014).

Note: also known from Namibia, Europe and Iceland (Guiry & Guiry 2014).

Acrochaetium reductum. 1. Young tetrasporophytes. 2. Tetrasporophyte with monosporangia.3. Gametophyte with monosporangia. (Illustrations reproduced from Stegenga et al. 1997).

Order Acrochaetiales

Family Acrochaetiaceae

Acrochaetium tenuissimum (F.S.Collins) Papenfuss 1945: 319

Plants epiphytic, with a fairly compact discoid multicellular base developing from a septately germinated spore; septation pattern typically three-celled. Erect filaments up to 0.5 mm tall, sparingly branched, 8-10 µm in diameter, the cells 12-20 µm long. Monosporangia sessile or pedicellate, lateral on the main axes, 19-22 x 10-13 µm.

Collections, ecology and regional distribution

Recorded from a few estuaries: Berg River on the west coast, Kowie at Port Alfred, and Mtakatye near Hlulkeka (11-45). It is epiphytic on the seagrass Zostera.

World distribution: According to Stegenga (1985) this species is found on seagrasses in various tropical to temperate localities around the world.

Type locality: San Pedro, California, U.S.A. (Silva et al. 1996).

Acrochaetium tenuissimum. 1. Germlings. 2. Habit of monosporangial plants. 3 Basal system of mature plant. (Illustrations reproduced from Stegenga et al. 1997).

Order Colaconematales

Family Colaconemataceae J.T. Harper & G. W. Saunders

Genus Colaconema Batters emend. J.T. Harper & G. W. Saunders

Thalli filamentous, monosiphonous, simple or branched, occasionally discoid and pseudoparenchymatous. In some species erect filaments are very short or virtually absent. Cells with one or more parietal chloroplasts which are discoid or irregular in shape (but never stellate), with or without pyrenoids. Life histories triphasic where known, asexual reproduction by monosporangia. Includes the members of the genus Audouinella dealt with by Stegenga (1985) and Stegenga et al. (1997), but follows the molecular study and re-classification of the Acrochaetiales by Harper & Saunders (2002). Descriptions and line-drawings where relevant are from Stegenga et al. (1997).

Besides the nine species recorded from the south coast, we have one probable record of Colaconema dictyotae (Collins) I.-K.Hwang & H.-S.Kim from Keurboomstrand, but insufficient material for illustrations.

Key to species

1a.Plants with the exception of reproductive cells completely endozoic or endophytic

2

1b. Plants with all or some vegetative cell filaments emergent

3

2a. Plants growing in sponges

C. spongicola

2b. Plants growing in seaweeds

C. endophyticum

3a. Plants matted; with extensive endophytic part and many multicellular pseudohairs (in Codium spp)

C. interpositum

3b. Plants forming individual tufts or partly endophytic/endozoic; pseudohairs rare or absent

4

4a. Monosporangia dome-shaped, with cup-shaped pedicel

C. daviesii

4b. Monosporangia ovate, cylindrical or sub-cylindrical; pedicel when present not cup-shaped

5

5a. Monosporangia usually at least 20 µm long, at least 12 µm in diameter

6

5b. Monosporangia between 10 and 20 µm long, up to 11 µm in diameter

8

6a. Monosporangia cylindrical/truncate, mainly on proximal cells of laterals

C. codicola

6b. Monosporangia ovate, terminal or inserted laterally on branches

7

7a. Single parietal chloroplast per cell, each with 2-4 pyrenoids

C. dictyotae

7b. Cells with 2-4 (-6) parietal chloroplasts each with central pyrenoid

C. caespitosum

8a. Monosporangia 16.5 – 20 µm long, 9-11 µm in diameter

C. nemalionis

8b. Monosporangia 10-12 µm long, 6-8 µm in diameter

9

9a. Erect filaments up to 2-3 mm tall, 6-8 µm in diameter, monosporangia in terminal or lateral clusters

C. pectinatum

9b. Erect filaments up to 800 µm tall, 10-12 µm in diameter near base, monosporangia in secund series

C. seriatum

Order Colaconematales

Family Colaconemataceae

Colaconema caespitosum (J.Agardh) Jackelman, Stegenga & J.J.Bolton 1991: 303

Plants bushy, up to 1 cm tall, epilithic, epiphytic, or with multicellular filamentous endophytic base. Erect filaments with laterals in short secund series, 15-20 µm in diameter, the cells up to 80 µm long; laterals frequently tapering into pseudohairs. Cells with 2-4 (-6) parietal chloroplasts, each a lobed plate with a central pyrenoid; in older cells the separate chloroplasts apparently fusing into a single cylinder, but the separate pyrenoids remaining recognizable. Monosporangia single or in small clusters, in short adaxial rows on the laterals, ovate, sessile or pedicellate, 20-30 x 15-17 µm.

Collections, ecology and regional distribution

Recorded from Kommetjie on the west coast of the Cape Peninsula to Hluleka (16-45). On the west coast this species is frequent as an epiphyte on stipes of the kelp Ecklonia maxima and also semi-endophytic on Codium spp. On the south coast it has been found as an epiphyte on stipes of Ecklonia radiata and on various other seaweeds including Dictyota, as well as on mussels and on rock in shaded parts of the upper eulittoral zone.

World distribution: widespread in temperate and tropical seas, under various names (Guiry & Guiry 2014).

Type locality: Brest, France (Athanasiadis 1996).

Notes: see Stegenga (1985 – as C. botryocarpa (Harvey) Stegenga) and Stegenga et al. (1997) for details of relationships with other species.

Colaconema caespitosum, erect axis with monosporangia (reproduced from Stegenga et al., 1997).

Order Colaconematales

Family Colaconemataceae

Colaconema codicola (Børgesen) H.Stegenga, J.J.Bolton, & R.J.Anderson 1997: 248, pl. 76 (1-2)

Plants bushy, up to 5 mm tall, with a multicellular filamentous endophytic base and several erect axes. Laterals polystichously arranged or in short secund series. Erect filaments 15-17 µm in diameter, towards the apex of the filaments tapering to 10-12 µm, but not developing pseudohairs; cells up to 60 µm long, with 2-4 lobed, parietal chloroplasts, each with a central pyrenoid. In older cells seemingly one parietal chloroplast, the separate pyrenoids remaining distinct. Monosporangia single or in small clusters, usually on the proximal cells of the laterals, cylindrical or truncate in shape 25-30 x 15-16 µm; tetrasporangia in similar positions, ovate, up to 35 x 25 µm, cruciately divided.

Collections, ecology and regional distribution

Recorded from Cape Agulhas to Hluleka (22-45), as an epiphyte on Codium spp.

World distribution: fairly widespread (under several names) in temperate seas (see Guiry & Guiry 2014).

Type locality: Canary Islands, without precise locality (Guiry & Guiry 2014).

Notes: also recorded from Langebaan Lagoon (Stegenga et al. 1997), which despite being on the west coast, can become very warm.

Colaconema codicola. 1. Detail of erect axis with monosporangia. 2. Tetrasporangia. (Reproduced from Stegenga et al. 1997).

Order Colaconematales

Family Colaconemataceae

Colaconema daviesii (Dillwyn) Stegenga 1985: 317, 320, fig. 20

Plants bushy, numerous erect filaments arising from a multicellular basal part. Erect filaments rarely over 1 mm high, (8.5) 9.5-11 µm in diameter, the cells 1-2 times as long as broad. Cells with a single parietal chloroplast and one pyrenoid. Indeterminate laterals few, polystichous; determinate branch systems with monosporangia more abundant. Monosporangia terminal in small corymbose branch systems, somewhat dome-shaped, 12-13.5 x 8.5-9.5 µm, with a cup-shaped pedicel.

Collections, ecology and regional distribution

Recorded along the west coast and as far as Hluleka (1-45). Plants epiphytic on various larger algae, or sometimes epizoic.

World distribution: virtually worldwide under various names (Guiry & Guiry 2014).

Type locality: probably North Wales (Silva et al. 1996).

Colaconema daviesii, erect axis with monosporangia. (Reproduced from Stegenga et al. 1997).

Order Colaconematales

Family Colaconemataceae

Colaconema dictyotae (Collins) I.-K.Hwang & H.-S.Kim 2011: 51, figs 38-40

Plants almost completely epiphytic, with creeping prostrate system of compact branched filaments bearing erect filaments. Erect filaments secundly to irregularly branched. Cells 12-18 µm in diameter and 25-50 (-60) µm long, narrower in laterals, each containing a single parietal chloroplast and 1-4 pyrenoids. Monosporangia ovate, 10-17 µm in diameter and 20-25 µm long when mature, usually sessile and solitary.

Collections, ecology and regional distribution

Recorded from Keurboomstrand and Natures Valley, on Dictyota sp. (31-32), but probably more widespread.

World distribution: Also recorded from California, China, Korea, Australia (Guiry & Guiry 2014).

Type locality: La Jolla, California (Womersley 1994).

Note: No satisfactory specimens for illustration – see Womersley (1994).

Order Colaconematales

Family Colaconemataceae

Colaconema endophyticum (Batters) J.T.Harper & G.W.Saunders 2002: 473 (as "endophytica")

Plants completely endophytic except for monosporangia. Filaments growing parallel to the host’s surface, irregularly branched, not coalescent. Cells cylindrical, 1-2 µm in diameter at filament apices, 3-4 µm in older parts of the plant; cells 10-15 µm long. Monosporangia developing terminally on short ‘erect’ filaments, projecting slightly from the surface of the host, 5-6 x 3-4 µm. (Description from Stegenga et al. (1997), as Audouinella endophytica).

Collections, ecology and regional distribution

Recorded from the Cape Hangklip area on the west coast to Tsitsikamma (19-32), on larger algae.

World distribution: Namibia, temperate eastern Atlantic, Mediterranean, Kamchatka (records from Guiry & Guiry 2014).

Type locality: Devon, England (Parke & Dixon 1976).

Note: this species resembles the two endozoic species Colaconema (as Audouinella) endozoica and Colaconema (as Audouinella) spongicola, but has even thinner filaments (Stegenga et al 1997).

Colaconema endophyticum. Habit of plant in cell wall of ceramiacean alga. (Reproduced from Stegenga et al. 1997).

Order Colaconematales

Family Colaconemataceae

Colaconema interpositum (Heydrich) H.Stegenga, J.J.Bolton & R.J.Anderson 1997: 250, pl. 78 (1-2)

Plants semi-endophytic, with an extensive system of endophytic filaments and numerous shorter emergent filaments. Cells of the endophytic system cylindrical or somewhat irregular, up to 12 (-15) µm in diameter and 30 µm long. Emergent filaments up to 200 µm long, branched, ca. 12.5 µm in diameter basally, tapering towards the apices, often terminating in multicellular pseudohairs; cells 2-3 times longer than broad, longer in the pseudohairs. Cells with a parietal chloroplast and a single pyrenoid; chloroplast in the endophytic cells often of irregular shape, the pyrenoid inconspicuous. Monosporangia terminal on emergent filaments and their laterals, subcylindrical, 20-22 x 9-11 µm.

Collections, ecology and regional distribution

Recorded from False Bay near Cape Point (Platbank) to Stilbaai (17-26), on Codium spp.

World distribution: South African endemic.

Notes: See Stegenga et al. (1997) for comparisons with records from New Zealand.

Colaconema interpositum. 1,2. Thallus details with monosporangia. (Reproduced from Stegenga et al. 1997).

Order Colaconematales

Family Colaconemataceae

Colaconema nemalionis (De Notaris ex L. Dufour) Stegenga 1985: 320, fig. 22

Plants bushy, up to 2 or 3 mm tall. Basal system multicellular filamentous, epiphytic or endophytic. Erect filaments 9.5-11 µm in diameter, the cells 2-5 times longer than broad. Cells with a single parietal chloroplast and one pyrenoid. Indeterminate laterals of varying abundance, polystichously arranged. Monosporangia in clusters on main axes and laterals; sporangia ovate, 16.5-19.5 x 9.5-11 µm . Tetrasporangia rarely seen in nature, in clusters like the monosporangia or single and pedicellate, 18-21.5 x 14.5-17 µm, cruciately divided. Gametophytes known from culture, with persistent basal spore, otherwise identical to the tetrasporophyte.

Collections, ecology and regional distribution

Recorded from Hondeklip Bay on the west coast to Kei Mouth (5-43). Epiphytic or epi/endophytic on several algae; endophytic parts only produced on hosts with looser surface tissue, such as Codium spp.

World distribution: Probably worldwide in temperate seas (Stegenga et al. 1997).

Note: Stegenga et al. (1997) point out that this species is almost certainly identical to Acrochaetium corymbiferum (Thuret) Batters, the life history of which is described by Abdel-Rahman et al. (1990).

Colaconema nemalionis, erect axis with monosporangia. (Reproduced from Stegenga et al. 1997).

Order Colaconematales

Family Colaconemataceae

Colaconema pectinatum (Kylin) J.T.Harper & G.W.Saunders 2002: 473

Plants with a multicellular filamentous basal system and several well-developed erect filaments. Erect axes up to 2 or 3 mm tall, sparingly branched, but with numerous small clusters of mono- and/or tetrasporangia. Erect axes 6-8 µm in diameter, the cells 3-6 times as long as broad. Sporangial clusters distichously arranged, one or two per main axial cell. Monosporangia terminal or lateral, 10-12 x 7-8 µm; tetrasporangia in identical positions, 17-21.5 x 12-14.5 µm, cruciately divided. Gametophytes minute, with a unicellular base and one or two very short erect axes (only known from culture).

Collections, ecology and regional distribution

Recorded from Doring Bay on the west coast to Tsitsikamma (8-32), on subtidal sessile animals (e.g. sponges) or sometimes on kelp.

World distribution: Australia, California, Atlantic Europe (localities from records in Guiry & Guiry 2014).

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

Note: Stegenga (1985) provides more information, and detailed illustrations on South African material of this species (as Audouinella pectinata) and discusses its relationship with close relatives.

Colaconema pectinatum, erect axes with monosporangia. (Reproduced from Stegenga et al. 1997; as Audouinella pectinata).

Order Colaconematales

Family Colaconemataceae

Colaconema seriatum (Børgesen) Stegenga 1985: 323, fig. 24 ('seriata')

Plants bushy, up to 800 µm tall, comprising a pseudoparenchymatous disc of multicellular densely interwoven filaments up to a few hundred µm in diameter, bearing numerous erect filaments. Cells of basal disc 4-5 µm in diameter, slightly longer than broad. Erect filaments frequently branched, laterals in alternate, irregular or secund series. Main filaments 10-12 µm in diameter, tapering to 7 µm near apices; laterals up to 7 µm in diameter. Cells 1.5-2.5 times as long as broad; chloroplast parietal with one pyrenoid. Monosporangia in secund series on the adaxial faces of primary and secondary laterals, sessile or pedicellate, 10(-12) x 6 (-8) µm. No other reproductive structures observed.

Collections, ecology and regional distribution

Recorded from Hluleka to northern KwaZulu-Natal (45-58), on larger algae.

World distribution: worldwide on tropical and warm temperate coast as C. seriatum (but see note below).

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

Note: C. seriatum is considered by some authors to be a synonym of C. hypneae. However, with some doubt we follow Stegenga (1985) in retaining the former name for South African material because it is never endophytic, despite often growing on a loose substratum (e.g. Codium platylobium) that would be conducive to an endophytic habit typical of C. hypneae in such circumstances. (See note in Stegenga 1985; as Colaconema seriata).

Colaconema seriatum. Habit of erect filaments with monosporangia (re-drawn from Stegenga 1985, Fig 24).

Colaconema seriatum. Detail showing chloroplast structure (both plants from type locality). Re-drawn from Stegenga 1985, Fig 24.

Colaconema spongicola (Weber-van Bosse) Woelkerling 1971: 41, fig.14A-F

Plants filamentous, irregularly branched; with the exception of monosporangia completely endozoic. Filament diameter 2-7 µm, the cells 1-10 times as long as broad, in general long and narrow cells in main filaments, short and broader cells in lateral branches. Monosporangia exserted, ca. 9 x 7 µm.

Collections, ecology and regional distribution

Recorded from Hout Bay (west coast) to Bird Island (16-38), in subtidal sponges.

World distribution: also recorded from Indonesia and South Australia (W. Guiry in Guiry & Guiry 2017)..

Type locality: Aru Islands, Indonesia (Woelkerling & Womersley 1994).

Notes: see discussions (as Audouinella spongicola) in Stegenga (1985) and Stegenga et al. (1997) for further illustrations and details of relationships with other species.

Colaconema spongicola, in sponge. Host surface shown by dotted line. (Reproduced from Stegenga et al. 1997; as Audouinella spongicola).

Order Nemaliales

Family Galaxauraceae (see Huisman et al., 2004)

Dichotomaria Lamarck 1816:145 (amended by Huisman et al. 2004 and Wang & Liu 2005).

Holdfast discoid, formed of compact rhizoidal mass; axes terete or flattened, pseudo-dichotomously branched, with or without distinct segments; primary growth from meristematic cells at centre of rounded spices; medulla filamentous; life-history triphasic with gametophytes and tetrasporophytes isomorphic in appearance but different in cortical anatomy; cortex of gametophyte usually with 3 layers, inner 1-2 of large clear cells, outer of smaller pigmented cells; cortex of tetrasporophyte with 3-6 layers, inner 1-3 of large clear cells, outer borne on pigmented stalk cells. Spermatangia borne in sunken cavities. Mature cystocarp hemispherical, immersed in cortex/medulla, with ostiole and persistent pericarp. Tetrasporangia cruciately divided, solitary or in sori on surface of thallus, tetrasporangia borne laterally on stalk cells of epidermal cells or terminally on epidermal cells. Twenty two species are currently recognised (W. Guiry in Guiry & Guiry 2015), of which three are found on the South African south coast.

Key to species

1 a. Axes strap-shaped, not jointed

D. diesingiana

1 b. Axes terete or compressed, jointed

2

2 a. Axes terete, marked constrictions between joints

D. obtusata

2 b. Axes compressed, usually not constricted at joints

D. tenera

Order Nemaliales

Family Galaxauraceae (see Huisman et al., 2004)

Dichotomaria diesingiana (Zanardini) Huisman, J. T. Harper & G. W. Saunders 2004: 230

Thallus erect, pinkish-red to brownish-red, up to 25 cm tall, dichotomously branched, moderately calcified; lower 1-2 cm usually terete and hirsute, remainder flattened, 2-5 (-7) mm wide, frequently branched, often rugulose, unsegmented, apices rounded. Internal structure comprising medulla of interwoven filaments 10-15 µm in diameter, cortex of gametophytes and tetrasporophytes somewhat different in structure. Cortex of tetrasporophytes with inner region of two layers of large globose or subglobose cells and outer region of ovate or clavate pigmented epidermal cells borne on stalk cells; tetrasporangia cruciately divided, borne on short stalk cells. Cortex of gametophytes with 3-4 layers of compact large cells that decrease in size towards exterior.

Collections, ecology and regional distribution

Epilithic in the lower eulittoral and shallow sublittoral (to at least 14m), mainly in wave-exposed localities. Recorded from Arniston along the south coast and the whole Kwazulu-Natal coast.

World distribution: Also recorded from Mozambique (Papenfuss et al. 1982).

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

Note: This and other South African Dichotomaria species (as Galaxaura) are described in detail by Papenfuss et al (1982).

Dichotomaria diesingiana, shallow subtidal, Haga Haga.

Order Nemaliales

Family Galaxauraceae

Dichotomaria obtusata (J. Ellis & Solander) J. V. Lamouroux 1816: 262-263

Thallus erect, pink to dark red, smooth or hirsute, or up to 25 cm tall, terete, moderately calcified, regularly dichotomously branched, arising from compact rhizoidal holdfast; axes cylindrical, distinctly segmented with marked constrictions, segments varying in size from 0.5-2.5 cm long and 1-3.5 mm in diameter, rounded at both ends, usually hairless, but sometimes covered with short red fur of assimilatory filaments. Internal structure of filamentous medulla and 3-layered cortex; outer epidermis of adherent pigmented cells, inner layers of clear, closely adherent, larger cells.

Collections ecology and regional distribution

Recorded from Goukamma eastwards to the north of Kwazulu-Natal (29-58). A subtidal species found down to at least 37m but also found in deep rock pools.

World distribution: Widespread in tropical seas, including Mozambique, Tanzania and Kenya (W. Guiry in Guiry & Guiry 2015).

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

Dichotomaria obtusata. Gametophyte on left (smooth surface) and tetrasporophyte on right (hirsute).

Dichotomaria obtusata: tetrasporophyte with surface hairs.

Dichotomaria obtusata, tetrasporangia borne on surface hairs of thallus, with numerous diatoms attached (Nature’s Valley).

Dichotomaria obtusata, detail of surface hair on sporophyte.

Order Nemaliales

Family Galaxauraceae (see Huisman et al., 2004)

Dichotomaria tenera (Kjellman) Huisman, J.T. Harper & G. W. Saunders 2004: 230

Thallus erect, bright reddish-pink, up to 12 cm tall, regularly (every 3-8 mm) branched, moderately calcified; lower 1-2 cm often terete and hirsute, axes compressed, jointed, usually not constricted at joints, 1-2.5 mm wide, often with inrolled edges forming ridges along margins; transverse striations present especially apically; well-developed rhizoidal holdfast. Internal structure of filamentous medulla and multilayered cortex; tetrasporophytes with inner cortex of two layers of globose/rectangular cells subtending a layer of slender stalk cells bearing an outer epidermal layer of subglobose or pointed epidermal cells, epidermal cells often not touching one another. Gametophytes with tightly adherent epidermal cells, some of which may bear pointed spinose cells.

Collections ecology and regional distribution

Recorded from Kei Mouth area eastwards to northern Kwazulu-Natal (43-58). Mainly a subtidal species, recorded to 43 m depth in Kwazulu-Natal (De Clerck et al. 2005), but also found in rock pools.

World distribution: Recorded from East Africa and also Mauritius (Børgesen 1942).

Type locality: Mombasa, Kenya (Silva et al 1996).

Note: This entity from the South Africa coast was previously known as Galaxaura tenera, but was synonymised with Galaxaura marginata (Ellis & Solander) Lamouroux by Papenfuss et al. (1982). Subsequently, Huisman et al. (2004) resurrected the genus Dichotomaria to include the G. marginata complex but recognised the South African entity as Dichotomaria tenera on account differences from Australian and Caribbean D. marginata. However, De Clerck et al. (2005) point out that some South African specimens do have apiculate epidermal cells and thus may not be distinct from D. marginata.

Dichtomaria tenera, shallow subtidal, Mzamba.

Dichotomaria tenera, close view.

Order Nemaliales

Family Helminthocladiaceae

Helminthocladia australis Harvey 1863: 39, pl. 272

Plants cylindrical, mucilaginous, flaccid, bright red, up to 50 cm tall, one to several main axes arising from a common holdfast, axes with numerous simple or re-branched laterals. Main axes between 2 and 10 mm in diameter. Structure multiaxial, with core of longitudinal filaments surrounded by radiating, dichotomously branched cortical (assimilatory) filaments. Terminal cells of cortical filaments swollen, obpyriform, 15-20 µm in diameter. Cells with a central stellate chloroplast and a central pyrenoid. Plants dioecious. Spermatangia in globose to irregular, loose clusters, terminal on assimilatory filaments. Carpogonial filament of 3 cells, subterminal on a cortical filament. Carposporophyte globose, immersed in thallus: gonimoblasts with terminal carposporangia: sterile involucre not well developed.

Collections, ecology and regional distribution

Found from the western side of the Cape Peninsula to Cape Morgan (16-43). In large pools and the sublittoral; probably a spring/summer annual (Stegenga et al. 1997).

World distribution: Also recorded from Australia, China, Japan, Taiwan, Korea and India (Guiry & Guiry 2009).

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

Note: The South African entity was previously known as H. papenfussii Kylin, but was synonymised with H. australis by Womersley (1965). The reproductive morphology of this species (as H. papenfussii) is detailed by Martin (1939).

Helminthocladia australis, fresh specimen from a rock pool, Cape Point.

Helminthocladia australis, closer view of fresh specimen from a rock pool, Cape Point (small Ceramium plants epiphytic on surface).

Helminthocladia australis. 1. Habit (apex). 2. Cross section showing cortical filaments and one carpogonial filament. Reproduced from Stegenga et al. (1997).

Order Nemaliales

Family Helminthocladiaceae

Helminthora furcellata (Reinbold in Tyson) Martin 1947: 371

Plants bushy, blackish, slippery, a few to 10 cm tall, with a single holdfast. Axes cylindrical, several times dichotomously branched, tapering in diameter from about 3mm basally to 1 mm at apices. Structure multiaxial, with a loose filamentous core surrounded by a cortex of radiating (assimilatory) filaments of progressively shorter cells. Cortical filaments dichotomizing at almost every cell; terminal cells club-shaped, 20-30 µm long and 10 µm in diameter. Cells with a single stellate chloroplast and a central pyrenoid.

Plants dioecious. Spermatangia in loose terminal clusters on the assimilatory filaments. Four-celled carpogonial filament with dumb-bell shaped carpogonium developing on swollen intercalary cells of the cortical filaments. Carposporophytes globose, immersed in subcortical layer, surrounded by involucre of sterile filaments. Tetrasporangia and life history unknown.

Collections, ecology and regional distribution

Found from Three Anchor Bay (Cape Peninsula) to Woody Cape (Addo), in intertidal pools, sublittroal fringe and shallow sublittoral zone. According to Stegenga et al (1997) this species is most prevalent in spring and early summer.

World distribution: South African endemic.

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

Note: Details of reproductive structures are provided by Martin (1947).

Helminthora furcellata (BOL), with some small Ceramium epiphytes.

Helminthora furcellata (BOL), closer view of terminal branches.

Helminthora furcellata. 1. Habit. 2. Cortical filaments. 3-9. Carpogobial filament and early developmental stages of carposporophyte. Reproduced from Stegenga et al. (1997).

Order Nemaliales

Family Scinaiaceae

Nothogenia Montagne

Gametophytes foliaceous or (in part) vesiculate. Medulla filamentous, cortex of anticlinal rows of small cells. Carposporangia and spermatangia formed in conceptacle-like cavities in the cortex. Life-histories heteromorphic; tetrasporophyte crustose, producing chains of cruciately-divided sporangia in the upper layers, surrounded by loose paraphyses. Life histories of South African species described by Anderson & Stegenga (1985).

Key to species

1 a. Thallus a gas-filled vesicle

N. ovalis

   b. Thallus foliaceous, rarely with swollen vesicular tips

N. erinacea

Order Nemaliales

Family Scinaiaceae

Nothogenia erinacea (Turner) Parkinson 1983: 609

Thallus foliaceous, yellowish-brown becoming black when dry, up to 35 cm long, rubbery/leathery becoming stiff when dry. Holdfast a small disc or crust; blades irregularly divided and incised and with numerous proliferations from surfaces and margins; blades to 5 cm wide. Internal structure multiaxial; medulla filamentous, cells 1.5-2.0 µm in diameter; cortex of anticlinal filaments ending in cells about 3 µm in diameter. Carposporophytes present as gonimoblasts lining the inner surface of conceptacle-like cavities; spermatangia in conceptacle-like depressions in surface of blade. Tetrasporophytes crustose, multilayered, with cruciately or irregularly-divided tetrasporangia in superficial sori among paraphyses; tetrasporangia 24-30 µm long, 10-17 µm wide.

Collections, ecology and regional distribution

Epilithic in the mid-lower eulittoral, often associated with sand. Found from Cape Fria in Namibia, along the west coast, to East London. (1-41).

World distribution: Southern African endemic.

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

Note: The life histories of this species and N. ovalis are described by Anderson and Stegenga (1985). The crustose sporophytes are apparently well-suited to surviving sand burial, so that these species are often associated with sand.

Nothogenia erinacea, typically on sand-affected intertidal rocks

Nothogenia erinacea, female gametophyte seen under water.

Nothogenia erinacea. 1. Habit. 2. Section of blade. Reproduced from Stegenga et al. (1997).

Order Nemaliales

Family Scinaiaceae

Nothogenia ovalis (Suhr) Parkinson 1983: 609.

Thallus a brownish- or yellowish-red, erect, gas-filled vesicle up to 5 cm tall; several vesicles arise from a common crustose base. Wall of vesicle composed of mainly anticlinal filaments, similar in structure to N. erinacea (above). Reproductive structure of gametophytes and crustose tetrasporophytes as for N. erinacea.

Collections, ecology and regional distribution

Epilithic in the eulittoral zone, where the small bladders may form patches. Found from Möwe Bay in Namibia, along the west coast, to Tsitsikamma (1-32).

World distribution: Also recorded from Tristan da Cunha (Baardseth 1941).

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

Note: Life history described by Anderson & Stegenga (1985).

Nothogenia ovalis, bladder-like thalli on rock covered by thin red crust, some of which may be the tetrasporophyte of this species.

Nothogenia ovalis, close-up of the bladder-like gametophytes.

Nothogenia ovalis, habit. Reproduced from Stegenga et al. (1997).

Order Nemaliales

Family Scinaiaceae

Scinaia Bivona-Bernardi

Thalli mucilaginous, comprising erect, branching axes that are soft or cartilaginous. Structure multiaxial, of interwoven longitudunal filaments inside a layer of radiating filaments surrounded by a solid epidermal layer. Currently accepted species total is 43, of which two are found on the South African south coast. (See also Stegenga et al. (1997).

Key to species

1 a. Thallus without distinctive constrictions; epidermis comprising interspersed colourless vesicular cells and pigmented assimilatory cells

S. capensis

1 b. Thallus distinctively constricted at forks; epidermis comprising only colourless vesicular cells

S. salicornioides

Order Nemaliales

Family Scinaiaceae

Scinaia capensis (Setchell) Huisman 1985: 417

Plants pale to bright red, mucilaginous, up to 10 (-14) cm tall, somewhat bushy, with small discoid holdfast. Axes erect, cylindrical, dichotomously branched up to 10 times, about 2 mm diameter (3 mm wide in pressed specimens), with blunt apices. Structure multiaxial, with a narrow core of densely interwoven longitudinal filaments surrounded by a layer of fairly loose radiating filaments with very narrow cells lumens, and a solid epidermal layer. Epidermis comprising a mixture of chloroplast-containing cells (about 5-10 µm in diameter in surface view) and broader, thick-walled colourless vesicular cells (up to 25 µm diameter in surface view). Spermatangia superficial, cut off from narrow epidermal cells. Carposporophytes globose, immersed in the sub-epidermal layer. Tetrasporophytes unknown.

Collections, ecology and regional distribution

Recorded from Melkbosstrand on the west coast to Mzamba (15-47). Found in lower eulittoral pools, the eulittoral fringe, and in the sublittoral. Most common in spring and early summer, but sporadic in occurrence.

World distribution: South African endemic.

Type locality: Port Alfred (Silva et al. 1996).

Notes: Stegenga et al. (1997) point out that the tetrasporic phase, which is unknown, may be “acrochaetioid” in form (i.e. an open filament), similar to that known for S. furcellata (Turner) Bivona (Boillot 1968), and therefore inconspicuous. S. capensis was previously known as Pseudogloiophloea capensis (Setchell) Levring. S. capensis has also been collected from Meeuw Island in Saldanha Bay. There is one unusually large specimen of S. capensis (more than 30 cm long), collected from Kowie, in BOL.

Scinaia capensis, underwater.

Scinaia capensis, underwater, showing bluish iridescence.

Scinaia capensis, cross-section showing faintly pigmented, narrow epidermal cells among larger colourless vesicular cells.

Scinaia capensis. 1. Habit. 2. Cross section of cortex. 3. Surface view of cortex. Reproduced from Stegenga et al (1997).

Order Nemaliales

Family Scinaiaceae

Scinaia salicornioides (Kützing) J. Agardh 1851: 423

Plants bright to dark red, mucilaginous, up to about 25 cm tall, with a small discoid holdfast. Axes erect, cylindrical, 1-4 mm in diameter, several times di- or trichotomously branched, distinctly constricted at forks. Structure multiaxial, with narrow core of longitudinal filaments surrounded by a layer of radiating filaments and a solid epidermal layer of colourless vesicular cells; assimilatory cells confined to subepidermal layers; vesicular cells broadly club-shaped, up to 20 µm diameter in surface view.

Spermatangia superficial, cut off in small groups from narrow spermatangial mother cells that penetrate the epidermis. Carposporophytes globose, immersed in the thallus. Tetrasporic phase unknown.

Collections, ecology and regional distribution

Recorded from Muizenberg (drift specimen) to St Lucia in Kwazulu-Natal (18-55); mainly a species of the South African east coast. Found in the eulittoral fringe and sublittoral zone.

World distribution: South African endemic.

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

Scinaia salicornioides. Herbarium specimen.

Scinaia salicornioides. Herbarium specimen.

Scinaia salicornioides. 1. Habit. 2. Cross section of cortex. Reproduced from Stegenga et al. (1997).

Order Gelidiales

Family Gelidiaceae

Gelidium Lamouroux

Thalli tough, small (about 10 mm) to large (up to 40 cm tall), red to reddish-brown to blackish, terete, compressed or flattened, sparsely to profusely branched. Holdfast of cylindrical or compressed, branched or unbranched, prostrate axes attached by rhizoidal haptera. Plants forming turfs or clumps, or solitary. Erect fronds often terete basally, becoming compressed or flattened distally. Structure uniaxial, apical cell small but distinct, cortex of anticlinal filaments visible in cross-section as several layers of small pigmented cells. Medulla filamentous, in cross-section showing large colourless cells interspersed with thick-walled rhizines that may also occur in inner cortical layers. Sporophytes producing sori with tetrasporangia or in some species, bisporangia, on apical branches or proliferations. Cystocarps bilocular, with ostioles on both sides, carposporangia borne on both sides of a septum dividing the cystocarp into two loculi.

A geographically widespread genus with representatives in temperate and tropical waters worldwide. At present 134 species are recognized worldwide (M. D. Guiry in Guiry & Guiry, 2015), 10 of which have been recorded on the South African south coast.

Key to species

1a. Mature erect axes longer than 6 cm

2

1b. Mature erect axes shorter than 6 cm

5

2a. Main axes and laterals terete, usually less than 1 mm in diameter, secondary branches often unbranched

G. abbottiorum

2b. Main axes and laterals compressed or flattened, usually more than 1 mm wide, secondary branches branched

3

3a. Plants brownish to blackish, main axes usually more than 2 mm wide, blades proliferating from the midrib, margins toothed

G. pristoides

3b. Plants purplish-red to red, main axes usually less than 2 m wide, blades proliferating from margins only, margins not toothed

4

4a. Lateral branches mostly at right angles to axis, terminal branches seldom overlapping each other

G. pteridifolium

4b. Lateral branches forming an angle of up to 45o with axis and often geniculate, branchlets often overlapping

G. capense

5a. Erect axes compressed to flattened, usually widening distinctly around origin of branches

G. crinale

5b. Erect axes terete, compressed or flatttened, not widening around branch origins

6

6a. Erect and prostrate axes cylindrical, about 250 µm diameter, only some apices of upright branches flattened

G. arenarium

6b. Erect axes largely or entirely flattened

7

7a. Erect axes flattened distally, with curled, twisted distal branches in up to 5 orders, plants up to 12 mm tall

G. De Clerckii

7b. Erect axes flattened, usually branched, distal branches not notably twisted

8

8a. Erect axes rarely simple, usually sparsely branched, branching distichous and irregular rather than pinnate, plants small (to 8 mm)

G. isabelae

8b. Erect axes at least in part with pinnate branches or pinnate marginal lobes

9

9a. Plants to 50 mm tall, foliaceous, erect axes pinnately branched

G. micropterum

9b. Plants 20 mm or smaller, with extensive prostrate system

10

10a. Prostrate and upright axes (if present) flattened, plants growing in limpet “gardens” in lower eulittoral/ sublittoral fringe

G. micropterum

10b. Prostrate axes cylindrical, uprights flattened throughout or distally

11

11a. Uprights flat, 1-2 mm wide and up to 10 mm high, often with pinnate marginal lobes, sporophytes bearing bisporangia

G. foliaceum

11b. Uprights lanceolate to ligulate, cylindrical basally, becoming flattened, about 1 mm wide and up to 20 mm high, branching irregular to pinnate, sporophytes bearing tetrasporangia

G. reptans

Order Gelidiales

Family Gelidiaceae

Gelidium abbottiorum R. Norris 1990: 41, figs 2,3,7,8.

Plants erect, to about 20 (-30) cm tall, stiff and wiry, purplish red to pale at the tips; holdfast fibrous and bearing several to many uprights; axes terete to subterete, up to 1 mm in diameter; branching alternate to irregular, sparse basally to more regular distally; branches at wide angles, straight or curved, often reflexed especially if unbranched, terminal branches narrower than axis (to 250 µm in diameter). Anatomy of darkly pigmented outer cortical cells up to 8 µm in diameter grading into larger ovate or angular inner cortical cells up to 25 µm in diameter and attached by long arms to medullary cells; medullary cells with thick walls with filamentous appearance due to long extensions; refractive rhizines concentrated in bundles in inner cortex and scattered in medulla. Fertile branches terminal, often geniculate; tetrasporangia in sori; cystocarps biloculate, usually near apex of branchlets, which may have short sterile apical protuberance; male branchlets similar to tetrasporangial branchlets with sori of dense, elongated spermatangial cells.

Collections, ecology and regional distribution

Found on wave-exposed shores in the mid to lower eulittoral zone, sublittoral fringe and tidal pools. Recorded from Cape Hangklip (130 km west of Agulhas) to Kosi Bay in northern Kwazulu-Natal. (22-58).

World distribution: South African endemic.

Type locality: Widenham, Kwazulu-Natal (Norris 1992).

Note: This species was previously known as Gelidium amansii. G. abbottiorum is distinguishable from G. pteridifolium by its scruffy appearance and irregular branching (branches in the latter species are regular, imparting a fern-like appearance).

G. abbottiorum, Double Mouth.

G. abbottiorum, branching detail.

G. abbottiorum, xs through cortex and part of medulla.

G. abbottiorum, thallus apex. Reproduced from Stegenga et al. (1997).

Order Gelidiales

Family Gelidiaceae

Gelidium arenarium Kylin 1938: 8, fig. 2D

Plants up to 30 (-60) mm tall, comprising prostrate terete or compressed branches attached by rhizoids and bearing erect terete axes; branching irregular throughout, upright axes often unbranched, prostrate and erect axes up to about 250 µm in diameter. Anatomy of outer cortical cells (7-13 µm in diameter) subtended by larger inner cortical cells; medulla of large cells, rhizines sparse and mostly in medulla. Tetrasporangia in sori borne on spatulate apices of fertile uprights.

Collections, ecology and regional distribution

Lower eulittoral , often forming a turf with or without other seaweeds. Recorded from East London area to just north of Durban (41-51).

World distribution: Recorded from Kenya (Silva et al. 1996) and also from China (Xia et al. 2002).

Type locality: Isipingo Beach, south of Durban (Silva et al. 1996).

Note: Norris (1992) describes this species in some detail.

G. arenarium: part of plant showing two uprights (one tetrasporangial) and basal branching system (re-drawn from Norris 1992, Fig 2A).

Order Gelidiales

Family Gelidiaceae

Gelidium capense (S.G. Gmelin) P.C.Silva in P.C.Silva, E.G.Meñez, & Moe 1987: 26

Plants erect, up to 40 cm tall, cartilaginous, dark brownish-red; prostrate rhizomatous holdfast bearing several erect axes; axes cylindrical in basal regions, compressed above, up to 1.5 mm wide and about 0.8 mm thick, pinnately (oppositely or alternately) branched; branches not constricted at bases, often conspicuously geniculate, especially in distal (younger) regions, often overlapping each other. Anatomy of small (to 8 µm diameter) outer cortical cells and slightly larger (to 10 µm) inner cortical cells interspersed with large bundles of rhizines; medulla of large (to 25 µm diameter) rounded cells interspersed with isolated rhizines or small bundles of rhizines. Tetrasporangial sori in spatulate terminal branchlets. Cystocarps single in terminal branchlets, often with terminal sterile beak.

Collections ecology and regional distribution

Found on rock from the sublittoral fringe to at least 10 m depth. Recorded from just north of Cape Town (Melkbosstrand) to the southern border of Kwazulu-Natal (15-48).

World distribution: Also recorded from Madagascar, Mauritius, Amsterdam Island, Oman (Silva et al. 1996). A record from the Philippines is questionable (Silva et al. 1987 in Stegenga et al. 1997).

Type locality: Cape of Good Hope (Norris 1992).

Note: Norris (1992) notes that some G. capense specimens are difficult to distinguish from fertile specimens of G. abbottiorum, and suggest that either environment or hybridization may be responsible.

Gelidium capense.

Gelidium capense, cross section of thallus.

Gelidium capense, LS of blade showing tetrasporangia.

Gelidium capense, cross section through male plant showing clear layer of spermatangia around outer surface.

Gelidium capense. 1. Thallus apex. 2. Cross section of main axis. 3. Longitudinal section of tetrasporiferous branchlet. Reproduced from Stegenga et al. (1997).

Order Gelidiales

Family Gelidiaceae

Gelidium crinale (Hare ex Turner) Gaillon 1828: 362

Plants dark red to red-brown, cartilaginous, to about 30 mm tall; terete prostrate axes attached by compact groups of rhizoids and bearing erect axes; erect axes terete to compressed in basal regions, becoming compressed to flattened distally, simple or sparsely branched; branching irregular, often more developed near apices of erect axes and appearing dichotomous rather than pinnate; upright axes usually 150-200 µm wide, broadening to up to 400 µm around branching points, branch apices tapering to blunt points. Cortex of 3-4 layers of small pigmented cells surrounding medulla of larger thick-walled cells; rhizines abundant on medulla and inner cortex. Reproductive structures not seen.

Collections, ecology and regional distribution

Recorded from False Bay (Western Cape) to Cape St Lucia, Kwazulu-Natal (17-55), from the lower eulittoral into the shallow sublittoral zones, usually forming a short turf (Tronchin 2003).

World distribution: Widespread in temperate and tropical seas (Millar & Freshwater 2005).

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

Note: this species is reported to differ markedly in morphology, depending on the environments in which it occurs (e.g. Millar & Freshwater 2005) and to grow up to 6 cm tall. A number of unidentified specimens of Gelidium in South African herbaria (usually noted to form turfs in the intertidal zone, and with smaller dimensions than those above) may be variants of this species.

Gelidium crinale, Cape Morgan (BOL).

Gelidium crinale (scale values in cm).

Gelidium crinale, turf-like specimen from NSW, Australia (re-drawn from Millar & Freshwater 2005).

Order Gelidiales

Family Gelidiaceae

Gelidium De Clerckii E. M. Tronchin in Millar and Freshwater 2005: 236, figs. 53-65

Plants dark purple, up to about 12 mm tall, forming turf on rock or mollusc shells, comprising dense branched uprights arising from cylindrical prostrate axes; prostrate axes about 125 µm in diameter, irregularly attached by rhizoids that either taper or end in brush-like haptera; uprights cylindrical to subcylindrical in proximal regions becoming flattened and broadening distally to up to 600 µm wide, apices blunt, sometimes bi- or tripartite, often lacerated, uprights often with surface papillae or proliferations, branching irregular, mostly near bases or apices of uprights; distal branches in up to five orders, irregularly twisted and curled. Anatomy of pigmented cortical cells, outer cortical cells to 8 µm long, rectangular, inner cortical cells mostly globose and 6-10 µm in diameter; rhizines clustered between inner cortical cells and interspersed throughout medulla; medullary filaments thick walled and up to 17 µm wide; cell dimensions of cylindrical stolons slightly larger. Tetrasporangial and spermatangial sori sub-apical, on both surfaces of blades. Tetrasporangia 22-34 µm long and 22-30 µm wide in surface view; cystocarps unknown.

Collections ecology and regional distribution

Collected in the East London area (Kidd’s Beach and Nahoon Point; 41), as a short turf on rock and mollusc shells in the eulittoral zone (Millar and Freshwater 2005). This inconspicuous and recently-described species is likely to be more widespread than current collections indicate.

World distribution: Known also from New South Wales, Australia (Millar and Freshwater 2005).

Type locality: Jervis Bay, New South Wales, Australia (Millar and Freshwater 2005).

Note: superficially similar to the numerous varieties of Gelidium pusillum that have been described from various parts of the world, G. De Clerckii is distinguished by “uprights with irregularly curled and twisted distal ends” (Millar and Freshwater 2005). It was discovered almost simultaneously in South Africa and Australia, and the conspecifity of the entities established by molecular studies.

G. De Clerckii, Kidds Beach (Type specimens, BOL).

G. De Clerckii, Kidds Beach (scale divisions = 1mm) (BOL).

Order Gelidiales

Family Gelidiaceae

Gelidium foliaceum (Okamura) E. M. Tronchin 2002: 556

Plants purplish-red to almost black, usually forming compact low carpet or turf; thalli comprising creeping cylindrical axes bearing determinate upright blades up to 1 cm long; blades flattened, ligulate to contorted, 1-2 mm wide, often with irregularly to pinnately arranged marginal lobes , margins crispate, entire to indented; anatomy of small darkly pigmented outer cortical cells grading into larger angular inner cortical cells; outer cells of medulla stellate with interconnecting slender arms; rhizines present throughout medulla. Reproductive structures borne in main blades or marginal lobes (branchlets); mono-or bisporangia produced instead of tetrasporangia; cystocarps bilocular.

Collections, ecology and regional distribution

Recorded from Goukamma to Sodwana Bay in northern Kwazulu-Natal (29 -56). Found in the upper and mid-eulittoral, usually forming a dense, short turf on rock, barnacles, limpets, etc.

World distribution: first recorded in Japan.

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

Note: this species should not be confused with the turf form of Gelidium pristoides (see Tronchin et al. 2002). Blades of the latter are well developed, with a midrib and toothed margins. G. foliaceum was previously known as Onikusa foliacea (Okamura) R. Norris.

Gelidium foliaceum, Morgan Bay, upper eulittoral boulders. The barnacle is about 15mm wide.

Gelidium foliaceum, Morgan Bay. Plants about 7 mm high, attached to piece of barnacle shell.

Order Gelidiales

Family Gelidiaceae

Gelidium isabelae W.R.Taylor 1945: 154,155, pl. 5: figs 8-12

Plants light to dark red, small (to 10 mm tall), turf-forming; terete prostrate axes attached by holdfasts of consolidated rhizoids, bearing erect axes of flattened, simple or branched blades. Erect axes lanceolate to clavate, 300 – 700 µm wide, terete at bases, branching distichous, apices obtuse, with prominent apical cell. Erect branches with cortex of 3-5 layers basally, 2-3 layers in distal flattened regions, surrounding medulla of thick-walled cells; rhizines in flattened distal regions restricted to medulla, also present in inner cortex in basal regions. Reproductive material not found in our area.

Collections, ecology and regional distribution

Recorded from Swartklip, False Bay to Port Elizabeth (17-36, but see note 2 below) forming a short turf in the eulittoral zone (Tronchin 2003).

Type locality: Isla Isabela, Galapagos Islands, Ecuador (Taylor 1945).

Notes:
1. See Millar & Freshwater (2005) for a detailed description of Australian material of this species. They report that adventitious attachments may form from terete outgrowths of erect blades, but we have not seen this in our material.
2. Norris (1992) described Gelidium minisculum (Weber-van Bosse) R.E. Norris, from Kwazulu-Natal, based largely on cultured material. Tronchin (2003) and Millar & Freshwater (2005) point out that cultured seaweeds can be morphologically different to those in nature. Based on morphological and indirect molecular evidence, they suggest that G. minusculum from South Africa may be referable to G. isabelae. If this is so, then the distribution would extend from False Bay to northern Kwazulu-Natal (17-58).

G. isabelae, Schoenmakerskop. Port Elizabeth (BOL, coll E.M. Tronchin).

G. isabelae, Schoenmakerskop. Port Elizabeth (BOL, coll E.M. Tronchin) (Scale divisions 1 mm).

G. isabelae, Specimen from Lord Howe Island, Australia (re-drawn from Millar & Freshwater 2005).

Order Gelidiales

Family Gelidiaceae

Gelidium micropterum Kützing 1868: 21, pl.59, figs c-g

Plants brownish-red, rather soft and fleshy, seldom more than 5 cm tall and often shorter; terete stoloniferous basal system bearing flattened erect axes up to 1.2 mm wide and about 150 µm thick, without midrib; Axes two (-three) times pinnately branched, ultimate and penultimate branchlets short, arising at short intervals. Small cortical cells grading into larger medullary cells, rhizines restricted to central medulla. Reproductive structure in ultimate or penultimate branchlets that tend to be roundish or ellipsoidal in outline; bisporangia in sori, transversely divided, about 40 µm long and 30 µm wide.

Collections ecology and regional distribution

Found in the lower eulittoral, rock pools and shallow sublittoral, often on shells of limpets or barnacles. Large plants are uncommon. A prostrate form of this species is common in the “gardens” of the limpet Scutellastra cochlear. Recorded from Buffel River on the northern west coast to central Kwazulu-Natal (3-51) (Tronchin, 2003).

World distribution: Probably restricted to South Africa: Stegenga et al. (1997) question the West African and Namibian records.

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

Note: We follow Stegenga et al. (1997) in including the morphological form found in the “gardens” of the limpet Scutellastra cochlear (formerly Patella cochlear). These plants are small, mostly prostrate, with compressed, sometimes “pinnately-lobed prostrate axes and short single or branched erect axes up to ca. 1 cm high”. As in “normal” G. micropterum, sporangial plants bear bisporangia.

G. micropterum, lower eulittoral zone, Saldanha Bay.

G. micropterum, detail of frond shape and branching

G. micropterum, thallus apex. Reproduced from Stegenga et al. (1997).

Order Gelidiales

Family Gelidiaceae

Gelidium pristoides (Turner) Kützing 1843: 407

Plants dark olive brown to black, tough, bushy with dense stoloniferous bases bearing several to many erect axes up to 10 (-20) cm tall; axes foliaceous, up to 3 (-5) mm wide, strap-shaped, proliferous, with toothed, undulating margins and distinct midrib about 0.5 mm thick; axes irregularly pinnately branched, branching also from midrib, whole plant thus not complanate. Rhizines abundant throughout central medulla and subcortical layer. Sporangial sori in marginal branchlets, producing bispores. Cystocarps protruding from both surfaces of fertile branchlets, usually with ostioles on both sides.

Collections ecology and regional distribution

Recorded from Sea Point, Cape Town, to Port Edward in Kwazulu-Natal (15-48), but most abundant on the south coast, where it is harvested commercially for the extraction of agar. Restricted to the eulittoral zone, where it is often dominant or abundant in the mid-lower eullitoral, growing on rock, shells of limpets, and tubes of the sandworm Gunnarea or coral-worm Pomatoleios. Sometimes forms a short dense turf in the mid-upper eulittoral; upright axes may then be less than 1 cm tall.

World distribution: South African endemic.

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

Notes: 1. This species was transferred to the genus Onikusa by Akatsuka (1986) but restored to Gelidium on the basis of morphological and molecular studies (Tronchin et al. 2002). 2. This is the most valuable commercial seaweed on the South African south coast, and its ecology and the effects of harvesting have been examined in some detail (see for example Anderson et al. 1991).

Gelidium pristoides, typical brownish-looking tuft. Siphonariid limpet in foreground is about 10 mm long.

Gelidium pristoides, underwater view of tuft growing on limpet shell.

Gelidium pristoides. Apex with bisporiferous proliferations. Reproduced from Stegenga et al. (1997).

Gelidium pristoides. 2. Cross section of main blade. 3. Section of proliferation with bisporangia.Reproduced from Stegenga et al. (1997).

Order Gelidiales

Family Gelidiaceae

Gelidium pteridifolium R.E. Norris, Hommersand and Fredericq 1987: 375, figs 1-7, 10

Plants erect, fern-like, up to 20 cm tall, reddish-purple, stiff and cartilaginous; holdfast fibrous and bearing many upright, axes terete only at origin with holdfast, then subterete to compressed, becoming flattened distally and 1-3 mm wide; branching pinnate, branches constricted near base, bearing evenly-spaced (1-2 mm) short determinate branchlets of approximately equal size and appositely arranged, subtended at almost right angles to the axis with apices blunt to acute. Anatomy of darkly pigmented , small (to 6 µm diameter) outer cortical cells grading into large (to 10 µm) inner cortical cells that become angular; medulla of thick-walled angular cells up to 25 µm in diameter, united into filaments; bundles of refractive rhizines concentrated in inner cortex, almost absent from medulla. Reproductive structures in slightly broadened regions of terminal branchlets; tetrasporangia in sori, branchlets usually with conspicuous apical notch: cystocarps biloculate, subterminal, branchlets often with long, pointed distal extension.

Collections, ecology and regional distribution

Recorded from False Bay to just north of Durban (17-51) and from Namibia (Rull Lluch 2002). Found from the sublittoral fringe (usually at wave-exposed sites) to depths of at least 15 m.

World distribution: Southern African endemic.

Type locality: Palm Beach, near Port Edward, Kwazulu-Natal (Norris 1992).

Note: Previously recorded as Gelidium cartilagineum (L.) Gaillon and as G. versicolor (S.G. Gmelin) Lamouroux, species which also included the entity currently recognized as G. capense.

Gelidium pteridifolium, Kenton-on-Sea.

Gelidium pteridifolium.

Gelidium pteridifolium, showing branching pattern.

Gelidium pteridifolium, thallus apex. Reproduced from Stegenga et al. (1997).

Order Gelidiales

Family Gelidiaceae

Gelidium reptans (Suhr) Kylin 1938: 6-7, figs. 2A-C

Plants brownish-red, sometimes with orange tips in the upper eulittoral, comprising creeping cylindrical axes bearing rhizoidal attachment pads and short erect blades at regular intervals; erect blades 0.5 – 2 cm long and up to 1 mm wide, single or in bundles, flattened or partly terete, lanceolate to ligulate, simple at first becoming sparsely irregularly to pinnately branched, branching at point of injury often digitate, apices rounded, margins entire. Anatomy of 2-3 layers of darkly pigmented, small cortical cells; medulla of thick-walled filaments interspersed with rhizines. Reproductive structures (tetrasporangia or bilocular cystocarps) in sori in slightly widened apices of erect axes or lateral branchlets.

Collections, ecology and regional distribution

Recorded from False Bay to Mozambique (17-58; De Clerck et al. 2005). Usually forming a sand-binding turf, found anywhere from the upper eulittoral to shallow subtidal zones, in rock pools and in estuary mouths; epilithic or epizoic on limpets or barnacles.

World distribution:Southern African endemic, also recorded from Namibia (Rull Lluch 2002).

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

Gelidium reptans, on rock from the shallow sublittoral, Morgan Bay.

Gelidium reptans, tuft approx 15 mm tall, showing creeping base – fresh material, Morgan Bay.

Gelidium reptans, detail under dissecting microscope. Plant approximately 12 mm high.

Gelidium reptans, XS of thallus.

Gelidium reptans. 1-2. Habit. 3. Apex of erct thallus. 4. Cross section of prostrate thallus. 5. Apex of tetrasporiferous blade. Reproduced from Stegenga et al. (1997).

Order Gelidiales

Family Gelidiaceae

Pterocladiella Santelices et Hommersand 1997

Small, dioecious or monoecious plants with holdfast of entangled stolons bearing distichously branched axes; axes flattened distally, branching one to several orders, alternate to irregular or regular to pinnate; cortex of 3-4 layers, medulla of thick-walled cells, rhizoidal filaments in medulla or cortex. Cystocarps arising from one side of the cystocarp floor, with chains of carposporangia radiating outwards; in cross –section, showing an almost triangular cavity and radial rows of carposrporqangia. Tetrasporangial sori elongate and either scattered over branches or restricted to terminal branches.

Contains 8 small species, mainly in tropical and subtropical areas (Santelices 1998).

Key to species

1a. Upright axes to 30 mm long and 1 mm wide, unbranched or sparsely, irregularly    branched

Pterocladiella
caespitosa

1b. Upright axes to 4 mm long, 100-400 µm wide, branchlets arising in pairs or whorls of up to 6

Pterocladiella
caloglossoides

Order Gelidiales

Family Gelidiaceae

Pterocladiella caespitosa (Kylin) Santelices 1998: 242

Plants bright purplish red, up to about 30 mm high, tufted, comprising a stoloniferous basal system bearing many soft flexuous upright axes. Prostrate axes cylindrical to subcylindrical, attached at intervals by tufts of rhizoids, up to 1 mm in diameter; upright axes sometimes unbranched, otherwise somewhat irregularly branched or with groups of branches arising near each other and giving an almost umbellate appearance, often with a series of small bladelets arising distichously in distal parts; branches flattened towards apices, blades up to about 1 mm wide and 200 µm thick. Branches often appear to regrow from grazed or damaged tips. Cortex of 3 pigmented layers, outer cell diameters 10-15 µm, increasing centripetally; medulla of 4-5 layers of larger colourless cells (to about 18 µm diameter), medulla in flattened blades up to 8 layers; rhizines present in medulla of thicker parts of blades but absent from some parts of prostrate axes and from upper (younger) regions of blades.

Tetrasporangia in sori covering all but margins of expanded ends of erect branches, tetrasporangia in young sori in chevron-shaped rows. Cystocarps single in distal bladelets, with gonimoblast attached to cystocarp floor and carposporangia in chains: single ostiole.

Collections, ecology and regional distribution

Recorded from Hluleka to northern Kwazulu-Natal (45-58). Known only from the lower eulittoral zone, forming tufts rather than extensive turfs.

World distribution: Also known from Mozambique, Kenya, Australia (Silva et al. 1996) and Seychelles (Santelices 1998).

Type locality: Isipingo Beach, near Durban (Silva et al. 1996).

Note: this species is described and illustrated in detail ( as Gelidium caespitosum Kylin) by Norris (1992). DNA analysis confirmed the identity of South African material (Tronchin 2003).

Pterocladiella caespitosa, specimens from Mabibi, KwaZulu-Natal (BOL).

Pterocladiella caespitosa, specimen from Mabibi, KwaZulu-Natal (BOL).

Pterocladiella caespitosa, cross section of thallus (re-drawn from Norris 1992, Fig 4F).

Order Gelidiales

Family Gelidiaceae

Pterocladiella caloglossoides (M.A. Howe) Santelices 1998: 244

Plants small (to 3 mm tall), turf-like, comprising a system of prostrate stoloniferous axes bearing irregularly branched upright or repent branches. Stoloniferous basal axes cylindrical to slightly flattened, attached usually at regular intervals by peg-like holdfasts of many rhizoids; upright branches usually arising at points of attachment, usually paired but sometimes in radially produced groups of up to 6, flattened except basally, up to 4 mm long and 100-400 µm wide. Outer cortical cells up to 12 µm in diameter and spheriodal, ovoid or rectangular in longitudinal section, inner cortical cells up to 15 x 18 µm ; medulla of single row of cells about 15 µm in diameter; rhizines scattered between inner cortical cells and medulla. Spermatangial sori covering surface of male branches except for margins and basal part; tetrasporangial sori terminal on broader branches, tetrasporangia arranged in characteristic chevron-like rows; cystocarps triangular in cross-section, with chains of carposporangia radiating from a basal, central area.

Collections, ecology and regional distribution

Recorded from the Morgan Bay area to northern Kwazulu-Natal (43-58), in eulittoral turf.

World distribution: Apparently widespread in tropical and temperate seas, in southern Africa also recorded from Tanzania (Silva et al. 1996).

Type locality: Not certain: either Isla San Lorenzo, Peru, from 5 m depth (Dawson 1953: 77) or San Felipe, Gulf of California (Xia & Wang 1999).

Note: This species was first recorded from South Africa as Pterocladia caloglossoides (Howe) Dawson by Norris (1987), who describes Kwazulu-Natal specimens in detail (see also Norris 1992).

Pterocladiella caloglossoides, BOL, annotated by RE Norris.

Pterocladiella calloglossoides, BOL, annotated by RE Norris, detail of one specimen.

Pterocladiella calloglossoides, XS (re-drawn from Norris 1992, Fig 5D).

Order Gelidiales

Family Gelidiaceae

Ptilophora Kützing

Thalli erect, up to about 35 cm tall (in south coast species), red. Holdfast fibrous. Erect axes cylindrical at base, otherwise winged and bladelike, up to 5 mm wide, midrib distinct at least in main part of main axes. Some species with small bladelike outgrowths from surface of midrib and/or blades. Branches arising from margins and /or surfaces main axes. Cross-sectional anatomy showing cortex of several layers of small pigmented cells, outer cells small, cells of inner layer(s) becoming larger; medulla of large colourless cells (longitudinally-arranged filaments); rhizines interspersed between cortical layers, absent from smaller blades. Reproductive structures borne in marginal bladelets, tetrasporangia in sori; cystocarps single, bilocular, with ostiole on each surface of bladelet.

Sixteen species are currently recognized in the genus; eight of these are found in South African waters (Tronchin 2003), of which we record two from the south coast..

Key to species

1a. Main branches strap-shaped, unbranched-sparsely branched

Ptilophora
diversifolia

1b. Main branches regularly pinnately branched, fern-like

Ptilophora
pinnatifida

Order Gelidiales

Family Gelidiaceae

Ptilophora diversifolia (Suhr) Papenfuss 1940: 214-216, fig. 11

Plants erect, red, up to 30 cm tall, with up to four orders of irregular, sparse branches; holdfast tough, fibrous; blades 2-5 mm wide, broadly winged, with distinct midrib throughout; distal branches mostly unbranched and up to 20 cm long, apices rounded; margins entire, undulate, crenate or eroded, and often bearing close pinnae; bases of branches often with reduced wings; blades smooth or rarely with numerous surface proliferations especially from the midrib. Vegetative anatomy of four layers; outer cortex of small, pigmented cells, inner cortex of larger cells, medulla of thick-walled filaments; outer and inner cortical layers separated by layer of rhizines. Reproductive structures borne on short bladelets arising from blade margins and surface; tetrrasporangia in sori; cystocarps bilocular.

Collections, ecology and regional distribution

Recorded from Port Elizabeth to just south of Durban (Tronchin 2003). Apparently a deeper-water species, either collected at depths of 30-40 m in Kwazulu-Natal or in drift.

World distribution: South African endemic.

Type locality: Between the Umtentu River (northern Transkei) and Umzimkulu River (Kwazulu-Natal) (Drege 1843: 155).

Note: This species is described and illustrated in detail by Norris (1992). P. diversifolia is considered to include the entity previously known as Ptilophora spissa (Suhr) Kützing (Tronchin 2003).

Ptilophora diversifolia, Mkambati.

Ptilophora diversifolia, detail of fronds.

Order Gelidiales

Family Gelidiaceae

Ptilophora pinnatifida J. Agardh 1885: 79-80

Fronds erect, red, up to 35 cm tall, complanate, with up to 5 orders of pinnate branches; thallus often partly to nearly completely covered by encrusting sponge; holdfast fibrous; proximal axis terete becoming flattened distally; midrib distinct except in ultimate and penultimate pinnae; distal pinnae 2-5 mm apart and up to 5 mm wide; mature ultimate pinnae curved, linear to cuneate; ultimate branch-ends somtimes shaped like oak leaves. Vegetative anatomy 4-layered; outer cortex of small pigmented cells, inner cortex of larger cells, medulla of thick-walled filaments; outer and inner cortical layers separated by layer of rhizines. Tetrasporangia and bilocular cystocarps in sori borne on narrow branchlets on apices or margins of ultimate pinnae; cystocarpic branchlets (ligules) may be up to 2 cm long.

Collections, ecology and regional distribution

Recorded from Algoa Bay to just south of Durban (36-50) (Tronchin 2003). Collected from sandy reefs at 30-40 m depth in southern Kwazulu-Natal, this species has otherwise only been found in beach-cast.

World distribution: South African endemic.

Type locality: Algoa Bay, South Africa (Tronchin 2003).

Note: this species is described and illustrated in detail by Norris (1992). Associations between Ptilophora species and encrusting sponges were investigated by Tronchin et al (2006), and P. pinnatifida recorded as one of the species that often forms these associations.

Ptilophora pinnatifida, Port Alfred (BOL).

Ptilophora pinnatifida, frond detai.

Ptilophora pinnatifida, frond detail: note fertile marginal branchlets.

Order Palmariales

Family Rhodothamniellaceae

Rhodothamniella floridula (Dillwyn) Feldmann in T.Christensen 1978: 67

Plants filamentous, caespitose, with an extensive system of prostrate filaments and a dense fur of erect filaments up to 30 mm high. Erect filaments sparingly branched, 19-25 µm in diameter, the cells 3-4 times as long as broad; cells with several (to 10) parietal, lobed chloroplasts, each with a central pyrenoid – in older cells apparently one chloroplast, the separate pyrenoids remaining visible. Tetrasporangia in small clusters, in uniseriate rows on the erect filaments; sporangia 30-35 (-40) x 25-30 (-35) µm, cruciately divided. Gametophytes only known from culture: small dioecious plants with a unicellular base. After fertilization the tetrasporophyte develops directly from the carpogonium/zygote; there is no development of a carposporophyte.

Collections, ecology and regional distribution

Recorded from Lamberts Bay on the west coast to Hluleka in the Transkei (9-45). Epilithic, forming turfs in the littoral zone, often sand-binding..

World distribution: Namibia, Atlantic Europe, Tristan da Cunha, Australia and Argentina (Kuipers in Guiry and Guiry, 2013).

Type locality: Galway Bay, Ireland (Silva et al., 1996).

Note: Stegenga (1985) describes South African specimens in detail, in his account of southern African Acrochaetiaceae, the family to which this species was formerly assigned.

Rhodothamniella floridula, stained microscope slide.

Rhodothamniella floridula, tetrasporangia.

Rhodothamniella floridula, vegetative cells with lobed, parietal chloroplasts.

Rhodothamniella floridula, 1. Microsopic habit. 2. Tetrasporangia. Reproduced from Stegenga et al. (1997).

Order Palmariales

Family Meiodiscaceae

Meiodiscus concrescens (K.M.Drew) P.W.Gabrielson in Gabrielsen et al. 2000: 42 (footnote)

Plants with a relatively extensive basal disc, consisting of confluent radiating cell rows, lateral cell fusions occurring at times. Erect filaments in clusters, short, usually not over 30 µm high, 7-10 µm in diameter, the cells about as long as broad. Tetrasporangia, the only known reproductive structures, terminal on the erect filaments, 17-20 µm x 15-17 µm, cruciately divided. (As Audouinella concrescens in Stegenga et al. 1997).

Collections, ecology and regional distribution

Known from sublittoral samples, on larger algae, west coast of Cape Peninsula to Tsitsikamma (16-32).

World distribution: widespread in cold temperate seas (Stegenga et al. 1997).

Type locality: Carmel Bay, California, USA (Guiry & Guiry 2015).

Meiodiscus concrescens, habit of plant on Ballia sertularioides, with tetrasporangia. Reproduced from Stegenga et al. (1997) (as Audouinella concrescens).

Family Bonnemaisoniaceae

Genus Asparagopsis Montagne 1841: xiv

Gametophyte thalli erect, long terete axes with dense plumose lateral branches; axes uniaxial, with axial cell and 3 pericentral cells; usually with additional cortication; numerous gland (secretory) cells present; monoecious or dioecious. Tetrasporophyte (“Falkenbergia”) phase filamentous, irregularly branched, forming tufts; axial cell with 3 pericentral cells, gland cells present; tetrasporangia formed by transformation of one of pericentral cells, tetraspores cruciately or irregularly divided.

The plumose gametophyte of Asparagopsis is only recorded on the south coast in Knysna Lagoon. The filamentous tetrasporophytes of the two species are indistinguishable, but most south coast material is thought to be A. armata (see Bolton et al. 2011).

Key to species

1a. Thallus plumose, bushy, to ca. 8 cm tall (gametophyte)

Asparagopsis
taxiformis

1b. Thallus filamentous, like pink/red tufts of cotton-wool (tetrasporophyte)

Asparagopsis
armata or
A. taxifomis

Order Bonnemaisoniales

Family Bonnemaisoniaceae

Asparagopsis armata Harvey 1855: 544

The gametophyte phase of this species has never been recorded in South Africa. Gametophytes of A. armata are similar to those of A. taxiformis. The main difference is that the former species is attached by spines on lateral branches but these are absent in A. taxiformis (see Womersley 1996 for descriptions and illustrations of both species).

The tetrasporophyte of A. armata was formerly known as Falkenbergia rufolanosa (Harvey) Schmitz in Engler and Prantl (see Stegenga et al., 1997). Plants filamentous, red to pinkish-red, forming cottonwool-like tufts up to a few cm in diameter. Thalli attached by multicellular haptera and comprising finely branched filaments: filaments irregularly branched, up to 50 µm in diameter, comprising narrow central cells with three pericentral cells, each with a refractive, globular inclusion; segments about as long as broad. Tetrasporangia one per segment, replacing a pericentral cell, tetrahedrally divided, about 40 µm in diameter.

Collections, ecology and regional distribution

The sporophyte is apparently distributed from the Cape Peninsula (False Bay) to at least Tsitsikamma and probably Port St Johns (Bolton et al., 2011). Epiphytic in the shallow sublittoral and tufts commonly drifting loose on the substratum.

Red, cottonwool-like tufts of the spoprophyte phase of Asparagopsis armata (centre) loosely attached to larger seaweeds, Tsitsikamma.

Sporophyte phase of Asparagopsis armata, previously known as Falkenbergia rufolanosa.

Sporophyte phase of Asparagopsis armata, detail of cells.

“Falkenbergia rufolanosa”, the sporophyte phase of Asparagopsis armata. 1. Thallus apex. 2. Attachment structure. 3. Tetrasporangia. Reproduced from Stegenga et al. (1997).

Asparagopsis taxiformis (Delile) Trevisan de Saint-Léon 1845: 45

Gametophytic plants pink to bluish-pink, forming soft, plumose bushes up to about 8 cm tall; attached by cylindrical stolons up to 2 mm in diameter; uprights comprising percurrent axis with dense determinate branches in all directions; basal parts of axes often stalk-like and without branches.

Tetrasporangial plants (“Falkenbergia” phase) forming tufts like pinkish-red cotton-wool, often entangled with other algae; thalli attached by multicellular haptera and comprising finely branched filaments with central axial cell and three pericentral cells; segments 30-40 µm diameter and 65-80 µm long at maturity; pericentral cells with a refractive, globular inclusion. Tetrasporangia one per segment, replacing a pericentral cell, about 40 µm in diameter, tetrahedrally divided (see illustrations of Asparagopsis armata tetrasporophyte).

Collections, ecology and regional distribution

On the south coast, the gametophyte phase of an invasive Indo-Pacific lineage of A. taxiformis is recorded only from the Knysna Estuary, growing subtidally in shallow water in the small-boat harbour on Leisure Isle (Bolton et al., 2011). An Atlantic/Mediterranean lineage (Bolton et al., 2011)) of the same species is recorded “once from Scottburgh in central Kwazulu-Natal, but is common north of Cape Vidal” (De Clerck et al. 2005).

World distribution: Found virtually world-wide in tropical and warm temperate seas (Guiry & Guiry 2009).

Type locality: Alexandria, Egypt (Silva et al. 1996).

Note: Tufts of “Falkenbergia” are common in the shallow sublittoral along much of the coast from False Bay to at least East London, and in northern Kwazulu-Natal. Because the tetrasporangial phases of A. taxiformis and A. armata (see later) are morphologically indistinguishable, the relative distributions of their Falkenbergia phases are uncertain, although current evidence indicates that “Falkenbergia” from False Bay to at least Tsitisikamma and probably to Port St Johns, is the sporophyte of A. armata (Bolton et al., 2011).

Asparagopsis taxiformis, Knysna Lagoon.

Asparagopsis taxiformis, Sodwana Bay – specimens growing on exposed coast, but a different genetic strain to the Knysna plants.

Asparagopsis taxiformis, single branch of Knysna specimen.

Asparagopsis taxiformis, detail of Knysna specimen.

Order Bonnemaisoniales

Family Bonnemaisoniaceae

Delisea flaccida (Suhr) Papenfuss 1940: 214

Plants bright red, erect, up to 30 (-40) cm tall, with small discoid holdfast; axes compressed, regularly alternately branched, about 3 mm wide and 1 mm thick, with regularly serrated edges. Structure monoaxial, with conspicuous central filament that is visible through the cortex in apical parts of the plant. One lateral arising from each cell of the central filament; laterals alternating and developing in sequence of about four determinate and one indeterminate branch. Cross section of mature parts of thallus showing prominent central cell surrounded by a narrow zone of small cells and a wide pseudoparenchymatous cortex, with cells markedly decreasing in size towards the surface of the thallus.

Plants dioecious. Spermatangia covering most of the surface of foliose branchlets with serrated edges on thallus margins. Cystocarps developing subterminally on indeterminate laterals, sessile, globose, with a terminal ostiole. Tetrasporangia not found.

Collections, ecology and regional distribution

Found from Olifanstbos on the Cape Peninsula (in drift) to the Great Fish River, east of Port Alfred (17-40). Subtidal; commonly found in drift.

World distribution: South African endemic.

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

Delisea flaccida (BOL).

Delisea flaccida (BOL) detail of fronds. Scale marking in cm.

Delisea flaccida 1. Habit. 2-3. Thallus apex. 4. Cross section showing central filament (dotted) and surrounding tissues. Reproduced from Stegenga et al. (1997).

Order Peyssonneliales

Family Peyssonneliaceae

Peyssonnelia Decaisne

Thalli crustose, adhering to substrate to some degree, if only proximally attached then shaped like a bracket fungus; structure of basal layer of horizontally-spreading branched filaments producing dorsal ascending filaments that may be coherent or relatively loose, and ventral rhizoids that may be unicellular or multicellular; cells of erect filaments calcified to varying degrees depending on species. Reproductive structures grouped in sori on dorsal surface, reproductive cells interspersed among sterile paraphyses.

Identification of species often requires vertical longitudinal sections through thalli to determine structure of the basal cell layer. Members of this genus often among the deepest-growing seaweeds. Currently 71 species recognized worldwide (Guiry & Guiry 2013), including two certain records from our area, but see note.

Key to species

1a. Crusts adhering tightly and almost completely to substratum; rhizoids unicellular

P. atropurpurea

1b. Thallus erect, comprising repeatedly branched axes a few mm wide

P. replicata

Order Peyssonneliales

Family Peyssonneliaceae

Peyssonnelia atropurpurea Crouan & Crouan 1867: 148

Plants dark red to almost black, glossy, crustose, several cm in diameter, strongly adherent with only extreme edge slightly raised. In radial vertical section thalli up to 500 µm thick, margin tapering, cells of basal layer long and narrow, some with one short unicellular rhizoid cut off anterior ventral end, calcification present in hypobasal layer; ascending filaments arising at acute angle and becoming erect near surface of thallus, internal calcification absent. Tetrasporangia in immersed sori that barely protrude above thallus surface, cruciately divided, up to 90 µm long and 30 µm wide, borne on short cup-shaped stalk cells. Paraphyses slender, up to 150 µm (7-10 cells) long. Sexual reproductive structures unknown.

Collections, ecology and regional distribution

Recorded in Namibia (Rull Lluch 2002) and along the South African west coast (Stegenga et al. 1997) to Morgan Bay (1-43). Found on crustose corallines and shells of some molluscs, in the sublittoral fringe and sublittoral zone.

World distribution: Europe, Morocco, Tunisia, also Queensland, Australia (Guiry & Guiry 2013).

Type locality: Brest, France (Guiry & Guiry 2013).

Note: Two other prostrate Peyssonnelia species were tentatively recorded from the south coast, but these require confirmation from better material. A possible specimen of P. calcea (now referred to Ramicrusta calcea (Heydrich) K.R. Dixon) was collected at Hluleka by Bolton and Stegenga (1987): this species is highly calcified (see Denizot 1968: p 132). Possible specimens of P. simulans were collected at Bird Island (Anderson & Stegenga 1989) and Natures’ Valley: these dark pink crusts are loosely attached, with unicellular rhizoids and only hypobasal calcification, rectangular to longish basal cells (to about 40 µm long), regular assurgent filaments, and well-developed nemathecia 100-150 µm deep with tetrasporangia 50-75 µm long and 15-30 µm wide surrounded by slender paraphyses of 5-10 cells (see also Denizot 1968: p 104).

Peyssonnelia atropurpurea on Scutellastra tabularis, sublittoral, Nature’s Valley.

Peyssonnelia atropurpurea on Scutellastra cochlear, Walker Point (BOL).

Peyssonnelia atropurpurea. 1. Radial section of thallus margin. 2. Thallus margin seen from below. 3. Radial vertical section. 4. Tetrasporangial sorus in section, one tetrasporangium extruded. Reproduced from Stegenga et al. (1997).

Peyssonnelia cf calcea, Hluleka (see note under P. atropurpurea).

Peyssonnelia cf simulans, on Scutellastra longicosta, Nature’s Valley (see note under P. atropurpurea).

Order Peyssonneliales

Family Peyssonneliaceae

Peyssonnelia replicata Kützing 1847: 775

Plants dark red to blackish, erect, complanate, branched, up to 10 cm tall; conical rhizoidal holdfast bearing short stipe and number of branching, flat axes with inrolled margins that may meet; branch segments 1.5-3 mm wide, broadening distally (to 5 mm or more) near rounded apices; ventral surface felty, uncalcified. In radial vertical section basal cells each bearing one multicellular rhizoid, rhizoids first growing parallel to ventral surface then curving downwards at right angles to it. Ascending filaments arising at about 45o to basal cell layer, curving slightly towards dorsal thallus surface; calcification absent. Reproductive structures not found.

Collections, ecology and regional distribution

Found from Port Alfred to St Lucia in Kwazulu-Natal (39-55). Epilithic, from eulittoral fringe to at least 35 m depth, often on rock near sand.

World distribution: South African endemic.

Type locality: Durban (Kützing 1847: 775).

Peyssonnelia replicata, sublittoral, Port Alfred (pressed specimen, BOL).

Order Peyssonneliales

Family Peyssonneliaceae Denizot

Sonderopelta capensis (Montagne) D.M. Krayesky in D.M. Krayesky et al. 2009: 385

Plants bright to dark red, crustose, fan-shaped, up to 6 cm long and 3 cm long, with variously-incised lobes. Thalli with only small basal area attached, and loose, projecting lobes (resembling bracket fungus). Dorsal surface smooth with concentric rings; ventral surface pale to beige, felty. In radial vertical section, thallus 300-400 µm thick, margin rounded, cells of basal layer each bearing 1-2 multicellular rhizoids on ventral side and ascending filaments at acute angles on upper side; ascending filaments curving upwards and becoming erect or almost erect only at the surface of thallus; cystoliths (calcified cells) conspicuous in middle to upper regions of thallus, also sometimes in hypobasal layer. Tetrasporangia in raised nemathecia, cruciately divided, about 50 µm long x 15 µm wide, borne on elongated stalk cells; paraphyses very slender, up to 120 µm (6-8 cells) long. Sexual reproductive structures unknown.

Collections, ecology and regional distribution

Found from the Cape Peninsula eastward along the rest of the South African coast (16-58), and in Mozambique and Tanzania, also in Angola. Subtidal, epilithic, commonly in caves, under overhangs or at depth: found to at least 30m.

World distribution: widely distributed in warm temperate and tropical waters of the Indian and Pacific Oceans (Guiry & Guiry 2013).

Type Locality: Durban (Silva et al. 1996).

Note: this species was previously known as Peyssonnelia capensis Montagne.

Sonderopelta capensis, showing concentric growth rings (Keurboomstrand).

Sonderopelta capensis, side view showing typical bracket-fungus- like habit. Threadlike structures below thallus are hydroids.

Sonderopelta capensis, radial section through vegetative thallus showing basal rhizoids and curved ascending filaments (stained microscope slide).

Sonderopelta capensis, radial section of tetrasporic thallus showing tbasal rhizoids, curved ascending filaments with dark cystoliths and tetrasporangia in surface nemathecium (stained microscope slide). Scale bar = 50 µm.

Sonderopelta capensis, section through edge of tetrasporangial nemathecium containing chains of tetrasporangia (stained microscope slide).

Sonderopelta capensis. 1. Habit. 2. Radial section. Reproduced from Stegenga et al. (1997)(as Peyssonnelia cpaensis).

Order Halymeniales

Family Halymeniacaeae

Codiophyllum natalense J. E. Gray 1872: 139-141, pl.IX

Plants living in a symbiotic relationship with a sponge; thalli red, up to about 25 cm tall, comprising a robust bare, rather “woody” terete to subterete stipe 5-20 mm in diameter and up to 10 cm long, branching distally, the branches bearing fan-shaped blades comprising an interwoven matrix of sponge tissue and filiform algal branches 100-200 µm in diameter. Medulla of compact filaments, some highly refractive; cortex of 4-5 layers of cells. Reproductive structures borne on small leaflets that are free of sponge; tetrasporangia abundant on both surfaces of leaflets, ellipsoidal and ca. 15 x 25 µm, cruciately or decussately divided. Cystocarps 120-150 µm in diameter, immersed in subcortical layer.

Collections ecology and regional distribution

Collected from Woody Cape, inshore of Bird Island (in drift), to Protea Banks (attached) in southern Kwazulu-Natal (37-48): De Clerck et al. (2005) point out that more northerly records (including that of the type specimen) are probably of drift specimens. Epilithic on deeper reefs (to at least 40 m); often a dominant species on deep reefs in southern Kwazulu-Natal (De Clerck et al. 2005) and usually found in beach-wrack, e.g. at Port Alfred.

World distribution: South African endemic.

Type locality: “Coast of Natal” (Gray 1872: 139) but reported to be Port Natal (Durban) by Papenfuss in Silva et al. (1996).

Note: A detailed description of this species is provided by Chiang (1970).

Codiophyllum natalense, Port Alfred (BOL).

Codiophyllum natalense, Woody Cape (BOL).

Codiophyllum natalense, “part of terminal margin of lamina” (re-drawn from Chiang 1970, Fig 20b).

Order Halymeniales

Family Halymeniaceae

Cryptonemia natalensis (J. Agardh) Chiang 1970:57-61 figs 27-29a, pl. 7

Plants bright red, foliose, slippery, up to 50 (-60) cm tall, stipitate, with one to several primary blades arising from a small discoid holdfast; stipe to several cm long, compressed basally, expanding gradually into a flat blade; primary blade usually linear-lanceolate, up to 4 cm wide, becoming sparsely irregularly or dichotomously branched with an indistinct basal midrib that disappears upward; linear-lanceolate proliferations arising from margins and distal edges of primary and later orders of blades; these proliferations simple or in turn branched; blade margins smooth, lacerate, or irregularly indented, sometimes minutely dentate; surfaces of blades sometimes perforated, speckled or with small papillae. Internal structure of filamentous medulla and cellular cortex; medulla comprising 60-70% of thickness of thallus and consisting of simple or branched elongated cells joined into filaments disposed in all directions, some cells larger and highly refractive; cortex of 5-7 layers of cells decreasing in size towards the thallus surface. Reproductive structures distributed throughout the blade and branches; cystocarps immersed, with well-developed pericarp; tetrasporangia immersed, arising from cells of third (rarely fourth) layer of cortex; spermatangia unknown.

Collections, ecology and regional distribution

Recorded from Kenton-on-Sea to Durban (38-51). A subtidal species, found to at least 37 m depth in Kwazulu-Natal (De Clerck et al. 2005).

World distribution: Endemic to South Africa.

Type locality: Port Natal (Durban) (De Clerck et al. 2005).

Note: The type description (Chiang 1970) gives details of the reproductive structure of this species.

Cryptonemia natalensis, Port Alfred specimen (BOL).

Order Halymeniales

Family Halymeniaceae

Grateloupia capensis O. De Clerck ex De Clerck, Gavio, Fredericq, Barbara & Coppejans 2005: 402-405, figs 7,8

Plants dark purplish to greenish-black, lax and slippery, pinnately to irregularly branched, usually with prolific shorter branches on proximal axes, up to 30 cm long but usually shorter, several axes borne on a common discoid holdfast. Axes complanate, 2-15 (-20) mm wide and 200-500 µm thick, surface proliferations common in middle parts of thallus. Medulla of loose filaments, with stellate cells in sub-cortical layer; cortex of anticlinal rows of 4-5 cells, outer cells 2-3 µm wide and up to 10 µm long. Reproductive structures produced all over thallus except in basal area. Tetrasporangia immersed in cortex, elongate, cruciately divided, ca. 15 x 35 µm. Gametophytes dioecious; cystocarps globose with prominent ostiole, immersed in thallus, spermatangia not seen.

Collections, ecology and regional distribution

Recorded from Namibia, along the whole west coast and as far east as Port Alfred (1-39). West coast specimens are often notably longer and broader than those from the south coast, which are usually 5-10 cm long and only a few mm wide. Occurring frequently in rock pools, usually in the mid-upper eulittoral zones.

World distribution: South African endemic.

Type locality: Kommetjie, Western Cape Province (De Clerck et al. 2005).

Note: Previously known as Grateloupia filicina, a species that was considered to be cosmopolitan, until G. filicina was shown by De Clerck et al. (2005) to be limited to the Mediterranean.

Grateloupia capensis, De Hoop (BOL). Scale divisions in cm.

Grateloupia capensis. 1. Habit. 2. Carposporohyte in cross section of thallus. 3. Section with tetrasporangia. Reproduced from Stegenga et al. 1997 (as G. filicina).

Order Halymeniales

Family Halymeniaceae

Genus Pachymenia J. Agardh

Thalli flat, foliose, incised or lobed, mucilaginous and slippery to cartilaginous, with discoid holdfast and little to no stipe. Structure multiaxial: cortex thick, with outer layer of radiating, branched filaments of somewhat elongated cells and inner layer of isodiametric cells that sometimes become stellate; medulla of sparse to dense irregular filaments, with or without refractice ganglionic cells. Life history with isomorphic sporophytes and gametophytes. Cystocarps with or without ostiole, immersed in thallus. Tetrasporangia excised from cortical cells, scattered and immersed in cortex, cruciately divided.

This genus is distributed widely in the Southern Hemisphere and comprises about 9 species. Some taxonomic uncertainly surrounds some of the species, and a number of species previously ascribed to the genus Aeodes (including the South African A. ulvoidea and A. orbitosa are now placed within Pachymenia (see Russell et al. 2009).

Key to species

1a. Thalli rather cartilaginous, with thickened margins and sometimes double-margins; subtidal

Pachymenia
cornea

1b. Thalli smooth, slippery, without thickened or double margins; usually intertidal

Pachymenia
ulvoidea

Order Halymeniales

Family Halymeniaceae

Pachymenia cornea (Kützing) Chiang 1970: 22-24, fig. 8

Plants red to purplish-red, foliose, orbicular to irregular in outline, up to about 30 (-40) cm in diameter, rather cartilaginous in texture: margins thickened and dentate, sometimes forming a double margin. Cortex of anticlinal rows of filaments, outermost cortical cells about 5 µm long and 1.0-1.5 µm in diameter; medulla of densely-packed filaments running in all directions. Tetrasporangia scattered in cortical layer of thallus, about 25 µm long, cruciately to decussately divided. Cystocarps immersed in thallus, apparently without ostiole.

Collections, ecology and regional distribution

Recorded from Namibia along the entire west coast of South Africa to East London (1-41). Epilithic in the sublittoral zone and recorded to at least 24 m depth in Tsitsikamma.

World distribution: Southern African endemic.

Type Locality: Cape Agulhas, South Africa (Chiang, 1970).

Pachymenia cornea, typical False Bay specimen.

Pachymenia cornea, bright orange-red specimen, Kenton-on-Sea.

Pachymenia cornea, XS of Kenton-on-Sea specimen above, showing cortex of anticlinal filaments and part of medulla of multi-directional filaments.

Pachymenia cornea, 1. Habit. 2. Cross section of cortex. Reproduced from Stegenga et al. (1997).

Order Halymeniales

Family Halymeniaceae

Pachymenia ulvoidea (F. Schmitz) L. Russell in Russell, Hurd, Nelson & Broom 2009: 1397

Plants red to purplish, flat, foliose, orbicular to irregular in outline often with somewhat dentate margin, up to -30 cm in diameter but usually smaller, about 250-300 µm thick, smooth, slippery, attached by discoid holdfast. Structure of anticlinal rows of branched cortical filaments and medulla of interwoven filaments that occupies half to two thirds of thallus thickness: cells of outer cortical layer about 5 µm long, slightly elongated, cells of inner cortical layer round to ovoid and about 5 µm µm in diameter. Medullary filaments aligned transversely or obliquely from cortex to cortex and surrounded by gelatinous sheaths, somewhat variable in density and direction. Tetrasporangia scattered abundantly in outer cortical layers of both surfaces of thallus, cruciately to decussately divided, about 25 µm long. Cystocarps embedded in thallus, about 180 µm in diameter, apparently without ostiole.

Collections, ecology and regional distribution

Recorded from Tsitsikamma to Qolora River, Transkei (31-42). Epilithic in the lower eulittoral to sublittoral fringe.

World distribution: Endemic to South Africa.

Type locality: Port Alfred (Silva et al. 1996).

Note 1: This species (as Aeodes ulvoidea) is described in detail by Chiang (1970).

Note 2: This entity was transferred from the genus Aeodes to the genus Pachymenia by Russell et al (2009) along with the west coast A. orbitosa, leaving only one (New Zealand) species in Aeodes.

Note 3: There are a number of specimens in BOL of an entity with the invalid name Aeodes digitata F. Schmitz (see Delf & Michell 1921: 117) from the Eastern Cape (mainly Port Alfred). These are similar in shape and size, but different in texture and colour, to the west coast species Pachymenia carnosa (J.Agardh) J. Agardh. While P. carnosa is dark red, thick, cartilaginous and does not adhere to paper when pressed, these specimens are light red, very thin and completely adherent. We have not collected specimens similar to “A. digitata”, which needs further investigation.

Pachymenia ulvoidea, lectotype specimen, Port Alfred (BOL).

Pachymenia ulvoidea, Port Alfred (BOL).

Pachymenia ulvoidea, fresh specimen, Double Mouth.

Order Halymeniales

Family Halymeniaceae

Polyopes constrictus (Turner) J. Agardh 1851: 239

Plants erect, dark red to blackish, 5-15 cm tall, comprising a tuft of branched cartilaginous uprights arising from a common, inconspicuous discoid holdfast; uprights subcylindrical to flat, 1-2 mm wide throughout, often with slight constrictions at irregular intervals, branching usually dichotomous, sometimes secund or opposite; margins entire or occasionally bearing lateral pinnate branchlets up to 2 (-5) mm long. Structure of cellular cortex and filamentous medulla. Medulla of dense, interwoven filaments interspersed with stellate cells and occupying 60-80% of the thallus thickness. Cortex of anticlinal rows of 8-12 cells (more in older parts) in dichotomously branched filaments; outermost cortical cells 2.5-3.5 µm wide.

Tetrasporangia produced only in nemathecium-like sori near the ends of uprights, sori elevated above or level with surface of cortex; sporangia immersed, about 25x10 µm, cruciately or decussately divided. Cystocarps immersed in thallus, lacking ostiole.

Collections, ecology and regional distribution

Recorded from Namibia and along the entire South African west coast to Kei Mouth (1- 43). West coast specimens can be notably longer (to 25 cm) than those from the south coast. Epilithic or sometimes epiphytic in the lower eulittoral to shallow sublittoral zone.

World distribution: Also recorded from southern Australia (Womersley & Lewis 1994).

Type locality: Bass Strait, Australia (Womersley & Lewis 1994).

Note: See Chiang (1970) and Womersley & Lewis (1994) for detailed descriptions of this species.

Polyopes constrictus, Jongensfontein (BOL). Scale values in cm.

Polyopes constrictus, Jongensfontein (BOL). Scale values in cm.

Polyopes contrictus. Left to right: habit, cross setion of thallus with tetrasporangial sorus, Detail of section through tetrasporangial sorus (largest terasporangium 25 µm long). Reproduced from Stegenga et al. (1997).

Order Halymeniales

Family Halymeniaceae

Genus Prionitis J.G.Agardh

Thalli erect, one to several cylindrical to subcylindrical upright arising from a discoid holdfast, dichotomously or irregularly branched, surfaces of uprights smooth or knobbly, . Structure multiaxial: medulla of densely interwoven longitudinal filaments; cortex of compact, branched anticlinal filaments of cells decreasing in size towards the surface. Sporophytes and gametophytes isomorphic. Tetrasporangia embedded beneath thallus surface, cruciately divided; gametophytes dioecious, cystocarps embedded within thallus, surrounded by envelope of interwoven filaments, ostiolate.

The genus comprises 19 currently recognised species, distributed mainly in the temperate north Pacific (Guiry MD in Guiry & Guiry 2017) .

Key to species

1a. Uprights uniformly slender (about 1 mm diameter) smooth

Prionitis
filiformis

1b. Uprights increasing in diameter distally (to up to 6 mm), knobbly and distorted

Prionitis
nodifera

Order Halymeniales

Family Halymeniaceae

Prionitis filiformis Kylin 1941: 13

Plants erect, up to 15 (-20) cm tall, comprising a clump of slender uprights arising from a common crustose holdfast; uprights dark red, greenish or purple, terete, uniformly about 1mm in diameter, sometimes simple but usually dichotomously branched 3-4 times, often with spindle-shaped proliferations up to 3 mm long towards their ends. Medulla of dense filaments, surrounded by inner cortical layer of stellate cells and outer cortical layer of small, pigmented cells. Reproductive structures borne on lateral proliferations.

Collections, ecology and regional distribution

Recorded from Port Elizabeth to Port Edward (36 – 48). Found on wave-exposed shores where it is epilithic in the lower eulittoral and shallow sublittoral zones.

World distribution: Also found on the west coast of North America (Silva et al. 1996).

Type locality: San Francisco, California (Silva et al. 1996).

Prionitis filiformis, Haga Haga.

Prionitis filiformis, Kenton-on-Sea, shown out of the water.

Prionitis filiformis, XS, showing medulla of dense filaments, surrounded by cortical cells.

Order Halymeniales

Family Halymeniaceae

Prionitis nodifera (Hering) Barton 1896: 459

Plants erect, up to 15 cm tall, comprising a clump of red, cartilaginous, tough, irregularly and sparsely branched, knobbly uprights arising from a crustose holdfast. Uprights sparsely and irregularly branched, terete basally becoming compressed, widening from a few mm at the base to ca 6 mm distally. Filamentous medulla surrounded by inner cortex of stellate cells and outer cortex of small, pigmented cells. Reproductive structures developing in the knobbly proliferations towards the ends of the thalli.

Collections, ecology and regional distribution

Recorded from Three Sisters (10 km east of Port Alfred) to northern Kwazulu-Natal (39-58). Found on wave-exposed shores, epilithic or rarely epiphytic in the lower eulittoral and shallow sublittoral zones.

World distribution: South African endemic.

Type locality: Durban, Kwazulu-Natal (De Clerck et al. 2005).

Prionitis nodifera, Mkambati, northern Transkei (BOL). Scale values in cm.

Prionitis nodfera, Mkambati, northern Transkei (BOL), single specimen. Scale values in cm.

Order Gracilariales

Family Gracilariaceae

Gracilaria Greville

Plants branched, varying in form from terete to flattened, and in size from a few cm to over 60 cm in length. Holdfast discoid or crustose, bearing one to many erect axes. Plants soft, cartilaginous, or leathery; smooth, dentate, or fimbriate; varying in colour from red, red-brown, olive, green, purple, to yellowish. Anatomy of pseudoparenchymatous medulla and cortex of one to several layers of smaller cells. Life history triphasic, isomorphic. Cystocarps visible as swellings; ostiolate, traversed by tubular nutritive cells that connect the gonimoblast to the pericarp; carposporangia catenate. Tetrasporangia either scattered or in nemathecia.

The genus is well-represented in tropical and temperate waters worldwide, with 167 species currently recognised (Guiry & Guiry, 2011). Five species are recorded from the South African south coast. South African Gracilaria and Gracilariopsis species are described in detail by Iyer et al. (2004), and the molecular systematic of the Gracilariacaeae discussed by Iyer et al. (2005a). Gracilaria is one of the most important genera of commercial seaweeds in the world, and many species are harvested or cultivated for their agar.

Key to species

1a. Plants terete, soft, stringy, about 1 mm in diameter, up to 60 cm long

G. gracilis
(see also Gracilariopsis)

1b. Plants terete or flattened, more than 1 mm wide, not stringy

2

2a. Plants terete, cartilaginous; whorls of teeth on axes

G. aculeata

2b. Plants with flat blades

3

3a. Blades wide (to 3 cm or more), plants large (to 25 cm)

G. capensis

3b. Blades less than 2 cm wide

4

4a. Blades less than 1 cm wide, blade surfaces smooth

G. beckeri

4b. Blades up to 16 mm wide, sparsely branched, surfaces of mature blades dentate or papillate

G. denticulata

Order Gracilariales

Family Gracilariaceae

Gracilaria aculeata (Hering) Papenfuss 1967: 99, 100

Plants yellow-brown to dark red, cartilaginous, erect, up to 20 cm tall, attached by discoid holdfast. Axes terete, 2-3 mm in diameter, with regular swellings bearing whorls of spiny teeth up to 2 mm long. Axes sparsely and somewhat irregularly branched, branches slightly constricted at bases. Anatomy of large-called medulla with cells in central region up to 250 µm in diameter, decreasing radially and surrounded by a cortex of 1-3 layers of small pigmented cells. Tetrasporangia cruciately divided, up to 25 x 25 µm. Cystocarps scattered over surfaces of branches, ostiolate, up to 1.2 mm high and 1.4 mm wide, pericarp up to 26 cell layers thick.

Collections, ecology and regional distribution

Recorded from Kenton-on-Sea to Cape Vidal in northern Kwazulu-Natal (38-56). Found in the lower eulittoral and shallow subtidal, usually in clumps in wave-exposed areas.

World distribution: South African endemic.

Type locality: Durban, South Africa (Iyer et al. 2004).

Note: Described in detail by Iyer et Al. (2004), who point out that this species is closely related to the tropical G. salicornia, from which it may have evolved.

G. aculeata, Palm Beach (BOL).

G. aculaeata, Port Alfred.

G. aculeata, cross section showing medulla.

G.aculeata, cortex and part of medulla.

Order Gracilariales

Family Gracilariaceae

Gracilaria beckeri (J.Agardh) Papenfuss 1952: 175-176

Plants erect, up to 25 cm tall, yellowish- red to greenish-red to red, somewhat cartilaginous, bushy. Holdfast crustose, stipe cylindrical, about 1 cm long, blades compressed, irregularly strap-shaped, up to about 8 mm wide. Branching up to 7 orders, irregular. Blade margins papillate, irregularly dentate or fimbriate, often with proliferations from margins. Medullary cells up to about 160 µm in diameter, becoming smaller outwards, transition to cortex abrupt; cortical cells pigmented, about 10 µm in diameter, in 2-3 layers in older blades. Tetrasporangia scattered singly in sori on both sides of blade, cruciately divided, up to 23 x 42 µm. Cystocarps prominent, on surface of blades, up to 1.2 mm high and 1.8 mm wide, constricted at base, ostiolate. Traversing nutritive filaments common in mature cystocarps.

Collections, ecology and regional distribution

Recorded from Kenton-on-Sea to Port Edward in southern Kwazulu-Natal (38-48). Found in the lower eulittoral and shallow subtidal zones.

World distribution: South African endemic.

Type locality: “The Kowie” (Port Alfred), South Africa (Iyer et al. 2004).

G, beckeri (BOL).

G. beckeri, Haga Haga.

Order Gracilariales

Family Gracilariaceae

Gracilaria capensis F.Schmitz ex Mazza 1907: (1905-1918): 134-136

Plants erect, flattened, purple to purplish-red, up to 30 (-33) cm tall. Holdfast discoid, stipe terete, to 1 cm long. Blades compressed, ligulate to wedge-shaped, up to 23 cm long and 7 cm wide, branching up to four orders, irregular; blade margins and surfaces smooth, apices obtuse or broad and flattened. Medullary cells to about 150 µm in diameter, smaller towards periphery, transition to cortex abrupt: cortex 3-4 cell layers of pigmented, small cells. Tetrasporangia in sori localised at tips of branches. Cystocarps prominent, about 1 x 1.3 mm, in localised areas on surface of distal blades.

Collections, ecology and regional distribution

Collected from De Hoop to Port Edward (24-48). Found in the shallow subtidal zone but apparently rather uncommon: most collections are from drift material.

World distribution: South African endemic.

Type locality: “The Kowie” (Port Alfred), South Africa (Iyer et al. 2004).

G. capensis, Port Alfred.

G. capensis. Port Alfred (BOL).

Gracilaria capensis, cross section through cortex.

Gracilaria capensis, cross section.

Gracilaria capensis, cross section through cystocarp.

Order Gracilariales

Family Gracilariaceae

Gracilaria denticulata F.Schmitz ex Mazza 1907: 138-139, Fig. 6

Plants purple to green, erect, firm-fleshy, strap-shaped, up to 17 cm tall, sparsely branched. Holdfast discoid to crustose, stipe terete, to 1 cm long. Blades irregularly sparsely branched, often with marginal proliferations or unbranched marginal laterals, up to 16 mm wide in middle, tapering distally, apices obtuse. Surfaces and margins of mature blades dentate or papillate, in young blades often smooth. Medullary cells up to 120 µm in diameter in middle of cross-section, decreasing in size towards the cortex, containing proteinaceaous crystals, transition from medulla to cortex abrupt in blades; cortex of 1-2 cell layers, cells pigmented, about 10 µm in diameter. Tetrasporangia evenly distributed in sori on both sides of blade, up to 25 x 35 µm, cruciately divided. Cystocarps evenly distributed on both blade surface, ostiolate, up to 1.6 mm high and 2 mm wide, constricted basally, pericarp to 30 cell layers thick, nutritive traversing cells common when mature.

Collections, ecology and regional distribution

Collected from Cannon Rocks to northern Kwazulu-Natal (38-58 ). Epilithic in the lower eulittoral and shallow sublittoral zones.

World distribution: Also recorded from Mozambique and reported from Mauritius, although there is some doubt about the latter record (De Clerk et al. 2005).

Type locality: “The Kowie” (Port Alfred), South Africa (Iyer et al. 2004).

Gracilaria denticulata, Mkambati (BOL).

Gracilaria denticulata (BOL).

Order Gracilariales

Family Gracilariaceae

Gracilaria gracilis (Stackhouse) M.Steentoft, L.M.Irvine & W.F.Farnham 1995: 115, figs 1-3, 5-18

Plants reddish brown to yellowish-brown, terete, firm, stringy and up to 1 m long, usually in clumps anchored in sand. Main axis fairly distinct, terete, up to 1.5-2 mm in diameter; branching polystichous, fisrt order laterals usually long flagelliform, second order laterals usually much shorter and narrower than main axis, tapering at both ends. Medulla with large cells up to 0.5 mm in diameter, cells decreasing in size radially, cortex of small (about 10 µm diameter) pigmented calls. Tetrasporangia not seen in our material. . Cystocarps rare in South African material, sparsely scattered on main axis and laterals, protruberant, about 800 µm in diameter, dome-shaped, ostiolate, with tubular nutritive traversing cells (filaments).

Collections ecology and regional distribution

Collected from some sheltered bays and estuaries: on the west coast in the Olifants River mouth, St Helena Bay, Saldanha Bay/Langebaan Lagoon and Hout Bay, and on the south coast from the Keurbooms River and Swartkops estuaries (8-36). Plants are invariably anchored subtidally in sand.

World distribution: Also known from Lüderitz Lagoon, Namibia and reported from temperate and tropical localities worldwide.

Type locality: “Padstow (Cornwall) and elsewhere” England, but locality of lectotype unknown (Steentoft et al. 1995).

Note: The taxonomy of this and other “stringy” Gracilaria and Gracilariopsis species has been notoriously difficult because of their lack of useful morphological characters, but is being resolved by molecular methods (e.g. Iyer et al. 2004). South African G. gracilis was previously known as G. verrucosa (Hudson) Papenfuss.

Gracilaria gracilis, Saldanha Bay.

Gracilaria gracilis, Keurbooms Estuary (BOL).

Gracilaria gracilis, cross section.

Gracilaria gracilis, cross section of outer medulla and cortex.

Gracilaria gracilis, cross section through cystocarp (nutritive filaments around carpospores mass barely visible).

Gracilaria gracilis, cross section to show nutritive filaments between pericarp wall and gonimoblast.

Gracilaria gracilis. 1. Habit. 2. Cross section of thick axis. 3. Cortex of narrow axis in cross section. 4. Cystocarp in section. Reproduced from Stegenga et al. (1997).

Order Gracilariales

Family Gracilariaceae

Gracilariopsis longissima (S.G.Gmelin) M.Steentoft, L.M.Irvine & W.F.Farnham 1995: 117

Plants reddish-brown to red or yellowish-brown, terete, firm, stringy, up to 1 m long, usually in clumps anchored in sand. Main axis fairly distinct, up to 2 mm in diameter, repeatedly and irregularly branched in up to 4 orders, branches tapering at both ends. Medullary cells up to about 250 µm in diameter in centre of cross-section, decreasing in size radially, transition to cortex abrupt; cortex 1-3 cells thick, pigmented, about 10 µm in diameter. Tetrasporangia not seen in our material. Cystocarps scattered irregularly over surfaces of branches, ostiolate, up to 1 mm high and 1.4 mm wide, lacking tubular nutritive (traversing) cells. Note that this species can only be distinguished from a stringy, terete Gracilaria such as G. gracilis by molecular methods or by microscopic examination of the cystocarps: nutritive cells are present in Gracilaria but absent from Gracilariopsis. For more details on South African Gracilariopsis, see Iyer et al. (2005a, 2005b).

Collections, ecology and regional distribution

Records from the west coast (St Helena Bay, Langebaan Lagoon and in Simonstown harbour) and on the south coast (Knysna Estuary), have been confirmed by molecular methods (Iyer et al. 2004)(11-30). This species is probably confined to very sheltered waters, and may be restricted to a few estuaries on the south coast. Plants are inevitably anchored in subtidal sand.

World distribution: Widely reported from tropical and temperate localities, but most records would require molecular methods to distinguish them from other “stringy” Gracilaria and Gracilariopsis species.

Type locality: Sheerness, Kent, England (Iyer et al. 2004).

Note: A new species of Gracilariopsis, G. funicularis Iyer, Bolton et Coyne, was described from Swakopmund, Namibia, and the De Mond (Heuningnes) Estuary on the south coast, by Iyer et al. (2005b), using molecular methods. This species is morphologically indistinguishable from Gs. longissima and Gracilaria gracilis. Gs. funicularis is typical of the genus in that traversing nutritive sells are absent from cystocarps.

Gracilariopsis longissima, Knysna (BOL).

Gracilariopsis longissima, Simonstown, cross section of cystocarp. Note absence of nutritive filaments between pericarp and gonimoblast.

Order Gracilariales

Family Pterocladiophilaceae

Gelidiocolax margaritoides (M.T.Martin & M.A.Pocock) K.-C.Fan & Papenfuss 1959: 33-34

Parasitic on Beckerella pinnatifida, forming small white pustules just visible to the naked eye; pustules composed entirely of parasite tissue, rhizoidal filaments penetrating into the host tissue; spermatangia, cystocarps and tetrasporangia on separate pustules. For further details see Martin & Pocock (1953)(as Choreocolax margaritoides) and Fan & Papenfuss (1959).

Collections, ecology and regional distribution

Recorded in the Port Alfred area (39). (Martin & Pocock 1953).

World distribution: Apparently a South African endemic.

Type locality: Kleinemonde, east of Port Alfred (Martin & Pocock 1953).

Gelidiocolax margaritoides. Tetrasporic pustule on host tissue. Drawn from photograph in Martin & Pocock (1953: Plate 10, Fig. c).

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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 BANGIACEAE

Porphyra capensis

Porphyra sp.1

FAMILY STYLONEMATACEAE

Stylonema alsidii

Stylonema cornu-cervi (see under S. alsidii)

FAMILY ERYTHROTRICHIACEAE

Erythrotrichia bertholdii

Erythrotrichia platyphylla

Erythrotrichia welwitschii

Membranella africana

Porphyrostromium boryanum

Sahlingia subintegra

FAMILY HILDENBRANDIACEAE

Hildenbrandia lecanellierii

Hildenbrandia rubra

FAMILY ACROCHAETIACEAE

Acrochaetium brebneri

Acrochaetium catenulatum

Acrochaetium hlulekaense

Acrochaetium moniliforme

Acrochaetium reductum

Acrochaetium tenuissimum

FAMILY COLACONEMATACEAE

Colaconema caespitosum

Colaconema codicola

Colaconema daviesii

Colaconema dictyotaei

Colaconema endophyticum

Colaconema interpositum

Colaconema nemalionis

Colaconema pectinatum

Colaconema seriatum

Colaconema spongicola

FAMILY GALAXAURACEAE

Dichotomaria genus

Dichotomaria diesingiana

Dichotomaria obtusata

Dichotomaria tenera

FAMILY HELMINTHOCLADACEAE

Helminthocladia australis

Helminthora furcellata

FAMILY SCINAIACEAE

Nothogenia erinacea

Nothogenia ovalis

Scinaia capensis

Scinaia salicornioides

FAMILY GELIDIACEAE

Gelidium abbottiorum

Gelidium arenarium

Gelidium capense

Gelidium crinale

Gelidium declerckii

Gelidium foliaceum

Gelidium isabelae

Gelidium micropterum

Gelidium pristoides

Gelidium pteridifolium

Gelidium reptans

Pterocladiella caespitosa

Pterocladiella caloglossoides

Ptilophora diversifolia

Ptilophora pinnatifida

FAMILY RHODOTHAMNIELLACEAE

Rhodothamniella floridula

FAMILY MEIODISCACEAE

Meiodiscus concrescens

FAMILY BONNEMAISONIACEAE

Asparagopsis armata

Asparagopsis taxiformis

Delisea flaccida

FAMILY PEYSSONNELIACEAE

Peyssonnelia atropurpurea

Peyssonnelia replicata

Sonderopelta capensis

FAMILY HALYMENIACEAE

Codiophyllum natalense

Cryptonemia natalensis

Grateloupia capensis

Pachymenia cornea

Pachymenia ulvoidea

Polyopes constrictus

Prionitis filiformis

Prionitis nodifera

FAMILY GRACILARIACEAE

Gracilaria aculeata

Gracilaria beckeri

Gracilaria capensis

Gracilaria denticulata

Gracilaria gracilis

Gracilariopsis funicularis (note only – see under genus description)

Gracilariopsis longissima

FAMILY PTEROCLADIOPHILACEAE

Gelidiocolax margaritoides

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.