Seaweeds of the South African South Coast

Book 5: Phylum Rhodophyta (Red Seaweeds)
Order Ceramiales (Part 1)

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
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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.

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First Edition, 2020

ISBN 0-0000000-0-0

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

INTRODUCTION TO THE RHODOPHYTA (red seaweeds)

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

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

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

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

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

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

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

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

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

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

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

SYSTEMATIC CLASSIFICATION OF SOUTH COAST RHODOPHYTA

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

BOOK 3

CLASS BANGIOPHYCEAE

Sub Class Bangiophycidae

Order Bangiales

FAMILY BANGIACEAE
      Porphyra capensis Kützing
      Porphyra sp. 1

CLASS STYLONEMATOPHYCEAE

Order Stylonematales

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

CLASS COMPSOPOGONOPHYCEAE

Order Erythropeltidales

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

CLASS FLORIDEOPHYCEAE

Sub Class Hildenbrandiophycidae

Order Hildenbrandiales

FAMILY HILDENBRANDIACEAE
      Hildenbrandia lecanellierii Hariot
      Hildenbrandia rubra (Sommerfelt) Meneghini

Sub Class Nemaliophycideae

Order Acrochaetiales

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

Order Colaconematales

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

Order Nemaliales

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

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

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

Order Gelidiales

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

Order Palmariales

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

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

Sub Class Rhodymeniophycidae

Order Bonnemaisoniales

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

Order Peyssonneliales

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

Order Halymeniales

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

Order Gracilariales

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

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

BOOK 4

Order Gigartinales

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

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

FAMILY PHACELOCARPACEAE
      Phacelocarpus oligacanthus Kützing
      Phacelocarpus tortuosus Endlicher & Diesing

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

FAMILY ARESCHOUGIACEAE
      Erythroclonium corallinum (Suhr) Holmes

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

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

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

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

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

Order Plocamiales

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

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

Order Rhodymeniales

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

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

FAMILY HYMENOCLADIACEAE
      Hymenocladia kallymenioides (Holmes) F. Schmitz

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

BOOK 5

Order Ceramiales (in part)

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

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

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

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

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

BOOK 6

Order Ceramiales (in part)

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

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

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

Sub Class Corallinophycidae

Order Corallinales

FAMILY CORALLINACEAE

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

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

SUB-FAMILY MASTOPHOROIDEAE
      Metamastophora flabellata (Sonder) Setchell

Order Hapalidales

FAMILY HAPALIDACAE
      Choreonema thuretii (Bornet) F.Schmitz

Order Ceramiales

Family Callithamniaceae

Callithamnion Lyngbye

Plants filamentous, alternately branched, with one lateral per segment; thalli polystichous or more or less complanate; filaments ecorticate or in older parts of the plant with a rhizoidal cortex. Tetrasporangia sessile on uiltimate and penultimate branchlets, tetrahedrally divided. Spermatangial heads pyramidal or hemiglobose, one to four heads sessile on cells of ultimate branch systems. Female reproductive structures developing on a subterminal intercalary cell, involving a supporting cell with a carpogonial filament, and a second fertile pericentral cell; carposporohyte developing from two auxiliary cells and forming typical twin gonimolobes, without involucral filaments.

Note: According to Guiry & Guiry (2015), “Feldmann-Mazoyer (1941) erected the genus Aglaothamnion for species with uninucleate cells, zig-zag carpogonial branches and lobed groups of carposporangia, and recircumscribed Callithamnion. Aglaothamnion is now sometimes regarded as a synonym of Callithamnion with insufficient evidence for separate evolutionary lines of development”. We follow Stegenga et al. (1997) and Stegenga (1988) in ascribing our taxa to Callithamnion.

Key to species

1a. Asexual plants with polysporangia

Callithamnion
collabens

1b. Asexual plants with tetrasporangia, occasionally bisporangia

2

2a. Plants spongy, the apices frequently with short spines; plants with a greenish sheen

Callithamnion
stuposum

2b. Plants of more open construction, not bearing truly spinous ramuli; colour red

3

3a. Plants mainly branched in one plane

4

3b. Plants polystichously branched, or distichously in terminal branches

5

4a. Cells throughout the thallus 1-2 times as long as broad

Callithamnion
tripinnatum

4b. Cells up to more than four times as long as broad. Species only found in estuaries with fresh water influence

C. sp. 2

5a. Apical cells of the ramuli extremely short, much smaller than the subapical cells

Callithamnion
granulatum

5b. Apical cells of the ramuli not much smaller than the subapical cells

6

6a. Terminal branch systems often complanate

Callithamnion
hookeri

6b. Terminal branch systems polystichous

7

7a. Cells of the main axis up to twice as long as broad

Callithamnion
cordatum

7b. Cells of the main axes relatively longer

C. sp. 1

Order Ceramiales

Family Callithamniaceae

Callithamnion collabens (Rudolphi) L.McIvor & Maggs 2002: 443

Plants on the South African south coast up to a few cm tall (on the west coast up to 30 cm). Usually with an endophytic base and a single or a few erect axes, no creeping filaments. No clear distinction between indeterminate and determinate branches, but laterals often much shorter than the main axis. Main axis and branches corticated by rhizoidal filaments, developing from the basal cells of laterals. Main axis up to 300 µm in diameter. Laterals one per segment, densely branched almost every segment, in actively growing parts to two cells beneath the apex. Laterals in roughly four rows. Apical cells pointed, in younger stages terminated by a hair. Polysporangia one per cell on the ultimate and sub-ultimate branches, round or oval, measuring ca. 70x60 µm and dividing into 8 or 16 spores. Male stands perfectly round, in much the same position as polysporangia, one spermatangial cluster per cell, at maturity ca. 50 µm in diameter, producing many spermatangia. Procarps develop a little distance beneath the apical cells of the branches, and produce twin gonimolobes from each of the two auxiliary cells – or only from one as the auxiliary cell from the supporting cell fails to develop. Mature carposporophytes naked, up to ca 250µm in diameter.

Collections, ecology and regional distribution

Common along the entire west coast and extending onto the south coast (but less common) as far as the Port Alfred area (1-39). Epiphytic on larger algae in the lower eulittoral and below.

World distribution: Also known from Namibia (Rull Lluch 2002) and Sri Lanka (Silva et al. 1996).

Type locality: Table Bay or Gordons Bay, (Western) Cape Province, South Africa (Silva et al. 1996).

Callithamnion collabens 1. Detail of thallus with polysporangia. Reproduced from Stegenga et al. (1997)(as Aristothamnion collabens).

Order Ceramiales

Family Callithamniaceae

Callithamnion cordatum Børgesen 1909: 10-11, figs. 5, 6

Plants up to 5 (-10) mm in length, with few erect axes although some secondary formation from recurving basal ramuli is possible. Main axis up to 100 µm in diameter, the cells about as long as broad, ecorticate although some cells lower down may form short rhizoidal filaments. Main axis clear, but ultimate branch systems subdichotomous, the apices blunt and ca. 15 µm in diameter; apices of the axes overtopped by crowded incurved laterals. Laterals branched from the basal cell, roughly issued at 90º between consecutive segments. Tetrasporangia sessile, usually one or two sporangia of different ages on one cell, at maturity measuring ca. 60-65 X 50-55 µm, tetrahedrally divided. Sexual plants dioecious. Spermatangial heads very small, up to two - four per cell in a row on the adaxial face of the ultimate and penultimate branchlets. Carposporophytes often quite deeply lobed, carpospores when ripe ca 25 µm in diameter.

Collections, ecology and regional distribution

Recorded from Cape Hangklip to the Three Sisters area near Port Alfred (19-39). Generally epiphytic on larger algae,e.g. Amphiroa ephedraea.

World distribution: Apparently widespread in warm temperate and tropical localities (various references cited in Guiry & Guiry 2015).

Type locality: Between St. John and St. Thomas, Virgin Islands (Silva et al. 1996).

Note: As the species is described from the tropics, there may be reason to doubt the identity of our species..

Callithamnion cordatum, showing carposporangia. Stained slide, subtidal material, Tsitsikamma.

Callithamnion cordatum 1. Main axis in proximal region. 2. Thallus apex with carposporophyte. Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Callithamniaceae

Callithamnion granulatum (Ducluzeau) C. Agardh 1828: 177

Plants (in the area) rarely more than 2 cm in length, as a rule epiphytic, with few erect axes and little or no creeping parts. Main axis in older parts fully corticated, with (much shorter) side branches roughly in four rows. Cells of main axis somewhat shorter to somewhat longer than broad, up to ca. 250 µm in diameter. Laterals branched from the first cell, with more or less recognizable main axis, in diameter ca. 75 µm at maximum, apical cells short and almost pointed without being acute. Tetrasporangia sessile on the cells of ultimate and penultimate branchlets, usually one per cell, measuring ca. 55 x 50 µm, tetrahedrally divided. Male stands one per cell, semiglobose, ca. 75 µm in diameter, producing many spermatangia on repeatedly branching systems of progressively smaller cells. Carposporophytes with twin gonimoblasts, the rounded lobes measuring ca. 200 µm in diameter at maturity, the individual carpospores ca. 40 µm across in largest diameter.

Collections, ecology and regional distribution

Recorded as a small epiphyte between Nature’s Valley and the Kei Mouth Area (31-43). It appears to be smaller than the plants that are described from Europe.

World distribution: widespread in the warm temperate and tropical Atlantic and Mediterranean.

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

Callithamnion granulatum, with carposporophyte. (On Cladophora rugulosa, Haga Haga, stained slide).

Callithamnion granulatum, with tetrasporophyte. (On Cladophora rugulosa, Haga Haga, stained slide).

Callithamnion granulatum, thallus apex. (On Cladophora rugulosa, Morgan Bay, stained slide).

Callithamnion granulatum, with tetrasporangia, stained slide.

Callithamnion granulatum, with spermatangial stands, stained slide.

Order Ceramiales

Family Callithamniaceae

Callithamnion hookeri (Dillwyn) S.F. Gray 1821: 324

Plants bushy, with obvious main axis, up to 5 cm tall, repeatedly branched, often laterals in part distichously arranged, in part polystichously. Main axis without cortication in younger parts (up to about 100 µm in diameter), the cells 1-2 times longer than broad; older parts of the main axis with a dense cortication of rhizoidal filaments originating from proximal cells of the laterals, increasing the axis diameter to 250 µm. Ultimate branch system roughly pinnate, ramuli straight, not overtopping the thallus apex; terminal cells blunt or tapered. Tetrasporangia in adaxial series on ultimate ramuli; one sporangium per cell, sessile, nearly globose, ca. 75 µm in diameter. Spermatangial heads pyramidal, with a ca. 5-celled central axis. Carposporophytes with rounded twin gonimolobes.

Collections, ecology and regional distribution.

A species of the upper intertidal zone, mixed with Bostrychia intricata. Recorded along the whole west coast as far east as Dwesa (1-44).

World distribution: widespread in the Atlantic, also recorded from Namibia and Chile (Guiry & Guiry 2015).

Type locality: Moray, Scotland (Dixon & Price 1981 in Guiry & Guiry 2015).

Callithamnion hookeri, detail of older axis with determinate laterals. (Reproduced from Stegenga et al. 1997).

Order Ceramiales

Family Callithamniaceae

Callithamnion sp 1 (= Callithamnion sp. in Stegenga et al. 1997, p. 402).

Plants erect, usually epiphytic, up to 1.5 cm tall on the south coast (up to 5 cm on the west coast). With a distinct main axis and numerous (often one per cell of the main axis) indeterminate laterals repeating the branching scheme of the main axis but usually much shorter. Apex hidden by young laterals. Main axis in the basal part covered with a filamentous medulla, reaching a diameter of ca. 250 µm; cells of the main axis varying in length from 1 to 4 times the diameter. Laterals of all orders polystichously arranged, the determinate branches subdichotomously ramified up to 4 times from the first cell onward. Apical cells rounded, ca. 12-17 µm in diameter, cells in non-growing portions more tapered. Tetrasporangia one or two per cell of (sub) terminal branch systems, measuring ca. 60 x 50 um, tetrahedrally divided. Spermatangial heads up to three per cell, together forming a flattened structure ca. 85 µm long and 25 µm tall. Carposporophytes with round twin gonimolobes of ca. 150 µm in diameter, the synchronously formed carposporangia up to 30 µm in diameter.

Collections, ecology and regional distribution

Recorded from the Cape Peninsula to Haga Haga (17-42).

Note: This species has been compared to C. cordatum (Stegenga et al. 1997). Both species cover almost the same stretch of the south coast; differences include the on-average longer cells in the main axis and the round gonimolobes in Callithamnion sp. 1.

Callithamnion sp.1, tetrasporangial, Morgan Bay.

Callithamnion sp.1, young carposporophyte, Morgan Bay (stained slide).

Callithamnion sp.1, view of thallus of young carposporophyte, Morgan Bay (stained slide).

Callithamnion sp.1, tetrasporangial, Morgan Bay, detail.

Order Ceramiales

Family Callithamniaceae

Callithamnion sp 2

Plants up to 3(-5) cm tall, regularly branched in one plane, rather open. Laterals occasionally branched from the first cell, but usually higher up. Apical cells ca. 10 µm in diameter, main axes to 100 µm in diameter, and the cells 3-4 times as long as broad, the axes without a regular cortication. Tetrasporangia borne singly or in short rows on the basal parts of laterals, strictly one per cell, measuring up to 65-70 Xx55 µm, tetrahedrally divided. Spermatangial stichidia one to four in a straight row per cell, the whole structure measuring ca. 75-100 µm long and 25 µm high. Carposporophytes prominent, consisting of two to four gonimoblasts; ripe gonimoblasts round, measuring ca. 250 µm in diameter. Ripe carpospores angular, ca. 35 µm in diameter. Carposporophytes with generally three involucral filaments developed from the cell below the one carrying the carpogonial filament and subsequently the gonimolobes. Involucre loose-filamentous, continuing growth and apparently capable of forming new carpogonial filaments.

Collections, ecology and regional distribution

Apparently limited to a few estuarine environments (Knysna, Kowie: 30-39?) and capable of withstanding low salinity.

Callithamnion sp. 2, tetrasporophyte, Kowie (stained slide).

Callithamnion sp. 2, detail of tetrasporophyte, Kowie (stained slide).

Callithamnion sp. 2, carposporophyte, Kowie (stained slide).

Order Ceramiales

Family Callithamniaceae

Callithamnion stuposum Suhr 1840: 293

Plants dense, spongy, up to 10 cm tall, with green or sometimes blue sheen. Main axis visible in the basal part of the plant, up to 100 µm thick when uncorticated, becoming covered with cortical filaments and thus increasing the diameter. Cortical filaments covered with short adventitious branchlets. Segments 2-3 times longer than broad. Laterals polystichously arranged, branched from the first cell, branching to the fifth or sixth order, the ultimate apices more distichous and often provided apically with a few spine-like laterals. Apices of the plant crowded, the laterals curved inward and hiding the apical cell. Tetrasporangia in series on the adaxial face of the laterals, one per cell, almost globose, measuring ca. 55 µm in diameter, tetrahedrally divided. Male stands one per cell in ultimate branch systems, almost erect with a relatively large basal cell, a ca. six-celled axis and many spermatangia, measuring ca. 35 µm in height. We have not seen female specimens, but De Clerck et al. (2005) indicate records of female plants (from KwaZulu-Natal) with reproductive structures (with involucral branchlets!).

Collections, ecology and regional distribution

Recorded from Swartklip, False Bay to Mabibi in northern KwaZulu-Natal (18-48). A species of mid-tide level down, the dense thallus often collecting many pieces of shell. Mainly epilithic or on inanimate substrata.

World distribution: Previously thought to be a South African endemic, it is however, reported from Puerto Rico (Ballantine et al. 2011).

Callithamnion stuposum, showing green iridescence, Hluleka.

Callithamnion stuposum, blue iridescent form, (Morgan Bay).

Callithamnion stuposum, lateral branch with tetrasporangia, reproduced from Stegenga et al. (1997).

Callithamnion stuposum, tetrasporangial (Double Mouth, stained slide).

Callithamnion stuposum, tetrasporangial detail, stained slide.

Callithamnion stuposum, terminal spinous branchlets, stained slide.

Order Ceramiales

Family Callithamniaceae

Callithamnion tripinnatum C. Agardh 1828: 168

Plants small, up to 10 mm tall. Thallus regularly complanate, with clear main axes and rarely more than three orders of laterals. Apical cell ca. 17 µm in diameter, the axes increasing to 100 µm in older parts, no cortication present, thallus apices not overtopped by the laterals. Cells throughout the thallus about 1-2 times as long as their diameter. Branches with a blunt apex. Tetrasporangia sessile, in adaxial series on the ultimate branches, one per cell, 55-60 x 45-50 µm. Spermatangia in 1 or 2 small clusters on cells of the ultimate branches. Clusters rarely longer than 3(-4) cells. Carposporophyte with rounded lobes ca. 125 µm in cross section, the ripe carpospores ca. 25 µm in diameter.

Collections, ecology and regional distribution

Recorded from Brandfontein, just west of Cape Agulhas (Stegenga et al. 1997) to Mkambathi (22-47). Epiphytic on several algae of different groups, growing in the sublittoral or littoral fringe.

World distribution: Mainly a species of the European warm temperate west coast.

Type locality: Atlantic France (Silva et al. 1996).

Callithamnion tripinnatum. Above: thallus apex. Below: tetrasporangia. (Reproduced from Stegenga et al. 1997).

Callithamnion tripinnatum. Sterile thallus epizoic on hydroid, Tsitsikamma. (Stained slide).

Callithamnion tripinnatum, with spermatangia. (Stained slide).

Callithamnion tripinnatum,  with tetrasporangia. (Stained slide).

Order Ceramiales

Family Callithamniaceaae

Crouania J. Agardh

Plants filamentous, irregularly branched, either monopodial or sympodial. Cells of the central axis each with a verticel of three whorl branchlets: axis with or without rhizoidal cortication. Tetrasporangia borne on the proximal cells of the whorl branchlets; spermatangia formed on apical cells of the whorl branchlets; procarps formed near the thallus apices, in the place of a whorl branchlet; carposporophytes with several gonimolobes, without special involucral filaments, but enclosed in whorl branchlets. Seventeen species are currently recognised (Guiry & Guiry 2015), of which two are found on the south coast.

Key to species

1a. Verticils embedded in mucilage sheaths, the external cells of successive whorls forming an almost continuous layer

Crouania
francescoi

1b. Verticils without obvious mucilage sheaths, the successive whorls clearly separate

Crouania
attenuata

Order Ceramiales

Family Callithamniaceaae

Crouania attenuata (C. Agardh) J. Agardh 1842: 83

Plants up to ca. 1 cm tall, rather irregularly branched, but monopodial. Basal parts creeping, attached by multicellular rhizoids developed from the basal cells of the whorl branchlets. Main axis up to 120 µm across in the basal part. Indeterminate laterals given off at intervals of as few as four segments to more than fifteen. Each cell of the indeterminate axes with three whorl branchlets, these trichotomously branched basally, a few times dichotomously in the sections above and unbranched for the last 2-4 cells; branchlets standing out almost straight, slightly curved up in the apices, no obvious mucilage sheaths apparent, size up to ca. 100 µm long. Tetrasporangia sessile/adaxial on the basal cell of the branchlets, obovoid, measuring ca. 50(-60) x 45 µm, tetrahedrally divided. Sexual reproductive plants not seen.

Collections, ecology and regional distribution

Recorded from False Bay to Double Mouth (17-43); although known as a tropical species as well, we have not seen it in Transkei, possibly because it is not frequently found. It is collected as an epiphyte on Zonaria subarticulata, but also in turfs on non-living substrata.

World distribution: widespread in tropical areas throughout the world (Guiry & Guiry 2015).

Type locality: Brittany, France.

Crouania attenuata. 1. Habit. 2 Detail of axis with whorl branchlets. Reproduced from Stegenga et al. (1997).

Crouania attenuata. Thallus with tetrasporangia, Vleesbaai. Stained slide material.

Crouania attenuata. Thallus with tetrasporangia, detail. Stained slide material.

Order Ceramiales

Family Callithamniaceaae

Crouania francescoi Cormaci, G Furnari et Scammacca 1978: 259-261, pls. I, II (= figs. 1-7) ('francisci')

Plants sympodial: some of the laterals grow to a bigger size than the main axis, though without much system, total height of the plants ca. 1 cm. Basal parts prostrate, attached by multicellular rhizoids from the basal cells of the branchlets. Main axes up to ca. 100 µm, the cells to about twice as long as broad. Indeterminate laterals originating at intervals of two or three segments, mostly to one side. Every segment with three determinate laterals, subterminal on the cells, in older segments arising almost in the middle of the cell; indeterminate laterals additional to the determinate laterals, originating somewhat higher up. Determinate laterals branched several times, with three (to four) branches per cell right to the top, cells ovoid. Laterals bent upward, the external cells forming an almost continuous layer, probably enveloped in slime. Determinate laterals up to ca. 100 µm long. Tetrasporangia almost round, attached to the lower cells of the determinate branchlets, remaining enclosed within the sheath of determinate laterals, almost round, measuring 60-75 µm in diameter, tetrahedrally divided. Sexual reproductive specimens not seen.

Collections, ecology and regional distribution

Recorded from False Bay to northern KwaZulu-Natal (Stegenga et al. 1997) (18-58). Occurs on a number of different algal substrata as well as on sponges, and also sometimes in algal turfs where substrata are uncertain.

World distribution: mainly a Mediterranean species, also recorded from Mauritania (references in Guiry & Guiry 2015).

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

Crouania francescoi. 1. Habit. 2 Detail of axis with whorl branchlets and indeterminate branch initial. Reproduced from Stegenga et al. (1997).

Crouania francescoi, vegetative thallus, Goukamma, Walker Point. Stained slide.

Crouania francescoi, tetrasporangial thallus, Goukamma, Walker Point. Stained slide.

Order Ceramiales

Family Callithamniaceae

Euptilota mollis (Wollaston) O. De Clerck 2004: 383 (as 'molle' )

Plants very flaccid and pliant, up to 13 cm tall, pinkish and pale, iridescent blue in situ. Indeterminate axes irregularly and dichotomously branched, with alternate to distichously-arranged, somewhat sparse, uncorticated determinate laterals; determinate laterals 1.4-2 mm long, branched in up to 5 orders, apices unbranched for up to 14 cells. Indeterminate branches cylindrical, up to 1 mm in diameter near base, arising at irregular intervals along main axes, strongly corticated to within a few mm of apices. Tetrasporangia sessile, forming singly on determinate branches, tetrahedrally divided, ovoid, 50-65 µm long. Male plants with spermatangia in clusters on short fertile axes arising from branches of the determinate laterals. Female plants bearing paired gonimoblasts surrounded by an involucrum. (Description adapted from De Clerck et al. 2005).

Collections, ecology and regional distribution

We have not collected this species on the south coast, but De Clerck et al. 2005 report that it is only known from the type locality and southern KwaZulu-Natal (47-49). Apparently a subtidal species, found down to at least 20 m.

World distribution: South African endemic.

Type locality: off Mtentu River, northern Transkei, South Africa (Silva et al. 1996).

Note: see detailed illustrations and description in Hommersand et al. (2004), and De Clerck et al. (2005). This species was formerly known as Carpothamnion molle (Wollaston) P.C. Silva.

Euptilota mollis (photo H. Verbruggen).

Euptilota mollis. Enlarged view of thallus showing typical iridescence, heavily corticated (thick) indeterminate laterals and uncorticated (feathery) determinate laterals (photo H. Verbruggen).

Order Ceramiales

Family Callithamniaceae

Heteroptilon pappeanum (Kützing) Hommersand in Hommersand, D.W. Freshwater, J. López-Bautista, & S. Fredericq 2006: 210-214, figs 4-6

Plants solitary, erect, up to ca. 20 cm tall, pinnately branched and complanate, the main axes somewhat compressed. Apical cell of the main axis cutting off segments by oblique septa; laterals one per cell, strictly alternate, determinate and indeterminate branches apparently not formed in a fixed sequence. Determinate laterals simple or with a few ramuli, remaining uncorticated except for a few proximal cells, up to 20 cells long and 50 µm in diameter, tapering towards the apex. Main axis and indeterminate laterals becoming corticated a short distance behind the apices; cortex consisting of short-celled filaments originating from the proximal cells of the laterals; cortex becoming several layers thick, enveloping the proximal cells of the laterals. Tetrasporangia on much-branched determinate laterals in older parts of the plant, terminal or lateral, ovate, up to 75 x 65 µm, tetrahedrally divided. Sexual reproductive structures not seen.

Collections, ecology and regional distribution

Found along the west coast, but just reaching Cape Agulhas (1-22). A subtidal, epilithic species.

World distribution: South African endemic.

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

Note: formerly known as Euptilota pappeana Kützing.

Heteroptilon pappeanum. 1 Detail of main axis with simple and pinnate laterals (note developing cortication). 2 Tetrasporangia. Reproduced from Stegenga et al. 1997 (as Euptilota pappeana).

Order Cermiales

Family Ceramiaceae

Acrothamnion preissii (Sonder) E.M. Wollaston 1968: 323, fig. 24

Plants differentiated into creeping axes of indeterminate nature and determinate axes lying more or less flat against the substratum. Main axis 50-75 µm in diameter, the cells 2.5-3 times as long as broad, ecorticate, as a rule with four determinate branches: two forming branched multicellular attachment filaments, 0-2 forming determinate branches up to 2.5 mm long, the remaining branches considerably shorter and similar to the branchlets of the longer determinate branches. Central axis of determinate branches in diameter differing little from the main axis, with two regular, opposite branchlets per segment (the basal cell with one branchlet), all branchlets perfectly in one plane. The latter up to ca. 200 µm long, consisting of several (5-10) pairs of opposite ramuli (the basal cell without ramification) and a conspicuous terminal gland cell ca. 25 µm in diameter. In some segments of the determinate branches a third, smaller branchlet present, with or without a terminal gland cell. Reproductive structures not seen in our material.

Collections, ecology and regional distribution

In our area only found at Mkambati, growing epiphytically on Spyridia cupressina and Inkyuleea beckeri (47).

World distribution: fairly widespread in tropical and warm temperate localities (Guiry & Guiry 2015).

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

Note: Our material seems to differ from the Australian type in the (relative) size of the central axis of determinate branches, being bigger to almost undistinguishable from the indeterminate main axis (cf. Womersley, 1998).

Acrothamnion preissii. Note terminal gland cells (dark dots). Stained slide material.

Acrothamnion preissii. Detail showing structure and terminal gland cells (dark). Stained slide material.

Order Ceramiales

Family Ceramiaceae

Amoenothamnion lycopodioides Stegenga 1986: 42-44, pl. 10

Plants minute, partly prostrate, the apices ascending; erect parts only a few mm high. Attachment by means of multicellular rhizoids growing from the basal cell of some of the whorl branchlets. Main axis with seemingly dichotomous branching, up to 40(-60) µm in diameter, the cells ca. twice as long as broad. Each axial cell provided with a whorl of four equal branchlets, each c. 80-100 µm long. In a typical form whorl branchlets branched trichotomously from their basal cell: the middle branch directed upward, parallel to the main axis and usually branched once (to twice); the other branches directed outwards and branched twice. The lower branching trichotomous, the upper one dichotomous. Apical cells of the branchlets acute, in the apical parts of the plant sometimes provided with a unicellular hair. Gland cells generally on the subapical cells of the branchlets, semiglobose, ca. 12 µm in diameter. Reproductive structures not observed.

Collections, ecology and regional distribution

Known only from the type collection at Arniston (23).

World distribution: South African endemic.

Type locality: Waenhuiskrans (Arniston) (Stegenga 1986).

Amoenothamnion lycopodioides. Habit. Re-drawn from Stegenga (1986), part of Fig. 10, 2).

Amoenothamnion lycopodioides. Detail of plant showing whorl branchlets. Re-drawn from Stegenga (1986), part of Fig. 10, 3).

Order Ceramiales

Family Ceramiaceae

Antithamnion Nägeli

Plants, filamentous, ecorticate, differentiated into long indeterminate axes and short determinate “whorl branchlets”, the latter in opposite pairs on each main axial cell, whorl branchlets in successive segments distichous or decussate. Gland cells often present, borne by special three- or four-celled ramuli. Carpogonial filaments borne on the basal cell of otherwise little-modified whorl branchlets. About 50 species currently recognised (Guiry & Guiry 2015), of which two are recorded on the South African south coast.

Key to species

1a. Species with gland cells; determinate ramuli branched alternately below the top

Antithamnion
diminuatum

1b. Species without gland cells; determinate ramuli branched only adaxially below the top

Antithamnion
hubbsii

Order Ceramiales

Family Ceramiaceae

Antithamnion diminuatum Wollaston 1968: 293 (incl. var. diminuatum and var. polyglandulum Stegenga 1986: 30)

Plants to a few cm long, partly repent and attached by rhizoids or haptera that develop from the whorl branchlets, the apices usually free from the substratum for some length. Cells of the main axis with two branchlets, decussate. Branchlets with a short basal segment without regular branching, but at a later stage this cell may develop up to three multicellular attachment filaments. Other segments may develop two opposite ramuli (lower segments) or alternating ramuli (upper segments) – the top (ca. 2-5 segments) remaining unbranched. Re-branching of the ramuli rare, except for the formation of more or less abundant (three- or four-celled) branchlets with a gland cell. Gland cells lens-shaped to almost round, ca. 12-35 µm in diameter. Branchlets up to 400 µm or 900 µm (“var. polyglandulum”) long. Main axis up to 75 µm (125 µm in var. polyglandulum) in diameter, the segments up to ca. 3 times al long.

Tetrasporangia borne on the basal cells of the ramuli of the pinnae, ovate, to 75x50 µm, cruciately divided. Spermatangial stands (rare) on the lower (but not the basal) segments of determinate branches, replacing ramuli, with a straight ca. six-celled axis bearing spermatangium mother cells. Carposporophytes (rare) with one hemispherical gonimolobe developed, another much smaller, to ca. 300 µm in diameter, the carpospores within a gonimolobe ripening simultaneously and measuring ca. 45 µm in largest diameter.

In the past this species was split into the typical variety and var. polyglandulum, with A. eliseae Norris as a third entity distinguished from Natal collections. Var. polyglandulum usually does not bear reproductive structures. This species often has strongly swollen gland cells, the cause or function of which is unknown.

Collections, ecology and regional distribution

Recorded from the Cape Peninsula on the west coast , along the whole south coast and into northern KwaZulu-Natal (17-57). A common constituent of algal vegetation at or below low tide level, often epiphytic on larger algae.

World distribution: also recorded from Namibia, southern Australia and some Atlantic Islands.

Type locality: Kangaroo Island, South Australia (Silva et al. 1996).

Antithamnion diminuatum. 1. Habit. 2. Tetrasporangia. 3. Detail of prostrate axis and pinnate branchlets, with numerous gland cells. Reproduced from Stegenga et al. (1997: fig 3 as var. polyglandulum, now subsumed into A. diminuatum).

Antithamnion diminuatum. Tetrasporangial plant, stained slide material.

Antithamnion diminuatum. Vegetative material: slide material, gland cells stained green.

Antithamnion diminuatum. Carposporophytes. Note: The large cells in the centre are part of a Griffithsia thallus.

Antithamnion diminuatum. Fresh material – note transparent gland cells.

Order Ceramiales

Family Ceramiaceae

Antithamnion hubbsii E.Y. Dawson 1962: 16, pl. 5: fig. 2; pl. 6: fig. 3

Plants differentiated into creeping filaments and erect filaments up to 6 mm high, little differing in cell size. Creeping filaments attached by multicellular rhizoids arising from the basal cell of laterals. Erect axes with pairs of branches, neatly in one plane, consisting of a main axis, the basal cell of which remains short and undivided, the next 6-8 segments with two opposite ramuli (often rebranched), the next 1-4 segments with a single abaxial branchlet, the top segments unbranched. Branchlets of limited growth to ca. 500 µm long, about 150 µm wide. Gland cells absent. Tetrasporangia implanted on the basal cell of some second-order ramuli, measuring ca. 75 x 50 µm, as a rule cruciately divided. Other reproductive structures not observed in South Africa.

Collections, ecology and regional distribution

On the African south coast known only from a single collection at the Xora River mouth, Transkei (collected by RJQ Tarr, May 1999).

World distribution: scattered temperate and tropical localities around the world (Guiry & Guiry 2015).

Type locality: Baja California, Mexico (Silva et al. 1996).

Antithamnion hubbsii, single erect axis of stained specimen. Dark ovoid shapes are tetrasporangia.

Antithamnion hubbsii, branches arising from main axis, stained specimen.

Antithamnion hubbsii, part of single erect axis, with tetrasporangia, stained specimen.

Order Ceramiales

Family Ceramiaceae

Antithamnionella Lyle

Plants filamentous, uncorticated, usually partly prostrate, partly erect: thalli differentiated into long indeterminate axes and short determinate whorl-branches. Whorl-branches occurring in numbers from 1 to 6 per segment, the number usually variable within the species. Gland cells more or less abundant, found on unmodified cells of the whorl-branches. Tetrasporangia formed on proximal cells of the whorl-branches, sessile or pedicellate, tetrahedrally divided. Spermatangial heads small, shortly cylindrical, developing on proximal cells of whorl-branches. Procarp formed on the basal cell of a reduced, two-celled whorl-branch, closely below the apex of erect indeterminate axes; main axes discontinuing growth with the production of a carposporophyte. Carposporophytes with a varying number of gonimolobes, without an involucre. Of the 25 currently recognised species (Guiry & Guiry 2015), five are recorded on the south coast.

Key to species

1a. Plants with two (more rarely three) laterals per cell

Antithamnionella
spirographidis

1b. Plants regularly with three or more laterals per cell

2

2a. Determinate laterals within one whorl strongly dissimilar

Antithamnionella
tormentosa

2b. Determinate laterals in a whorl of about similar development.

3

3a. Determinate laterals usually unbranched, or with one (to three) laterals

4

3b. Determinate laterals usually with alternating laterals

Antithamnionella
sp.

4a. Determinate laterals usually with prominent, almost globose gland
cells on the second cell

Antithamnionella
verticillata

4b. Determinate laterals with flattened gland cells higher up

Antithamnionella
ternifolia

Order Ceramiales

Family Ceramiaceae

Antithamnionella sp

Plants mainly creeping, with erect axes up to 2.5 mm tall. Repent axes up to 55 µm in diameter, the cells to ca. 175 µm long, all cells with regularly 4 laterals, indeterminate laterals replacing one of the determinate laterals, in vigorously growing erect axes every third segment, in repent filaments up to every segment. Attachment by haptera, usually one per segment of the prostrate axes, arising from the basal cell of one of the branchlets. Determinate branchlets up to 200 µm long (to 400 µm just below carposporophytes), with the basal cell almost similar to the other cells and unbranched, the next few cells with a branch alternately left and right; the laterals not really distinct from the main axis, but branching only from the second segment. Gland cells variable in number, from virtually none to two (to several) per branchlet, usually on the third or fourth cell from the base (on the branchlets immediately below a carposporophyte, also higher up). Gland cells ovate, ca. 15 (– 25) µm in largest diameter.

Tetrasporangia borne singly on the basal cell of the branchlets, measuring ca. 40-50x35-40 µm, tetrahedrally divided. Male stands on virtually all but the topmost segments of the branchlets, up to 4 stands per cell, consisting of 2(-3) vegetative cells, each bearing a few spermatangia. Female stands (when successful) seem to terminate vegetative development. About three gonimolobes present at the same time, when mature ca. 150 µm in diameter, the individual carpospores ca. 35 µm in largest diameter, in the gonimolobe all spores ripening simultaneously.

This species is rather similar to A. multiramosa Athanasiadis from southern Australia (Womersley, 1998) but A. multiramosa has 5 or 6 branchlets per main axial cell instead of the regular four in our species.

Collections, ecology and regional distribution

Known only from Mbotyi (46).

Note: These Mbotyi specimens are very similar to a few thalli collected from Bird Island (38) and they may represent the same species (see later figures).

Antithamnionella sp, Mbotyi. Tetrasporangial plant, stained slide.

Antithamnionella sp, Mbotyi. Detail of tetrasporangia, stained slide.

Antithamnionella sp, Mbotyi. Sterile plant, showing blue-stained gland cells.

Antithamnionella sp, Mbotyi. Carposporophyte, stained slide.

Antithamnionella, Bird Island. This entity may be the same as our Antithamionella sp. Stained slide.

Antithamnionella, Bird Island. This entity may be the same as our Antithamionella sp. Note the gland cells (stained slide).

Antithamnionella, Bird Island. This entity may be the same as our Antithamionella sp. Apex of one axis (stained slide).

Antithamnionella, carposporophyte, Bird Island. This entity may be the same as our Antithamionella sp. Stained slide.

Order Ceramiales

Family Ceramiaceae

Antithamnionella spirographidis (Schiffner) E.M. Wollaston 1968: 345, fig. 29

Plants with a faint difference between prostrate and erect parts, the latter up to ca. 1 cm high. Basal axes to ca. 75 µm in diameter, the cells to ca. 250 µm long. Majority of the cells with two opposite (sometimes three) branchlets, the latter usually unbranched and up to 15 cells long. Basal cell of the branchlets not significantly shorter than the other cells. Older branchlets often remarkably incurved. Frequently branched axes with alternating indeterminate branches every third segment. Gland cells more of less frequent, usually on the second – sometimes third - cell of the branchlets, ca. 15 µm in largest diameter.

Tetrasporangia singly on the first (and second) cell(s) of the determinate branchlets – occasionally further segments with sporangia, at maturity ca. 60 x 37 µm, tetrahedrally divided. Male stands on a number of consecutive cells of the determinate branchlets, one or two stands per cell, consisting of a central axis of about 3 cells, each bearing a few spermatangia. Female fertile axis two-celled, the carposporophyte developing on the basal cell; although the branch that develops the female structure seems to continue growing, most growth occurs in the indeterminate branch from the segment below. About three gonimolobes of different ages are visible at any time, each with simultaneous ripening of the carpospores. Ripe gonimolobes ca. 200 µm in diameter, carpospores ca. 30 µm in largest diameter.

Collections, ecology and regional distribution

A plant only found: on the south coast in the Kowie estuary, on the west coast at Kraalbaai (Langebaan Lagoon), implying a distribution between these sites (13-39?). In Europe this species is regarded as an (Australian) introduction, and it may have the same status in South Africa.

World distribution: widespread in temperate seas (Guiry & Guiry 2015).

Type locality: Type locality: Trieste, Italy (Womersley 1998).

Antithamnionella spirographidis. 1. Thallus apex. 2. Detail with tetrasporangia. Reproduced from Stegenga et al. (1997).

Antithamnionella spirographidis. Male plant, Kowie (stained slide).

Antithamnionella spirographidis. Female with young carposporophyte, Kowie (stained slide).

Antithamnionella spirographidis. Tetrasporangial plant, Kowie (stained slide).

Order Ceramiales

Family Ceramiaceae

Antithamnionella ternifolia (J.D.Hooker & Harvey) Lyle 1922: 350

Plants with creeping axes and erect apices up to 1.5 mm long (apparently longer in the Western Cape). Each cell of the main axis with 3 (or 4) laterals, the latter usually unbranched and up to ca. 12 cells long, often with a gland cell on the third to fifth cell, the latter ca. 15 µm in largest diameter and strongly flattened (occasionally, laterals have one to three adaxial branches). Indeterminate branches replacing one of the determinate branches, given off every third segment. Cells ca. 40 µm in maximum diameter, 2-3 times as long as broad. Rhizoids present on the basal cell of older branchlets, up to three per segment. The material from the south coast is smaller than reported from the west coast (as A. tasmanica –see Stegenga et al. 1997).

Tetrasporangia on the first (or first two) cells of the determinate branchlets, measuring 40x35 µm, tetrahedrally divided. Male stands not seen in south coast material although Stegenga et al. (1997) state that the species is monoecious (as A. tasmanica). Carposporophytes with up to 4 gonimolobes, at maturity ca. 100 µm in diameter, per lobe ripening simultaneously: carpospores up to 30 µm in diameter.

Collections, ecology and regional distribution

Recorded from False Bay to Port Alfred (17-39). Rare, epilithic or epiphytic/epizoic; most records from material washed ashore on mussel shells, Pyura tests, etc.).

World distribution: Widespread in temperate and tropical waters (Guiry & Guiry 2015).

Type locality: St Martin’s Cove, Cape Horn, Chile (Ricker 1987).

Note: We have included in A. ternifolia the entity previously referred to A. tasmanica.

Antithamnionella ternifolia. 1. Detail of main axis and whorl branches. 2. Tetrasporangia. Reproduced from Stegenga et al. (1997).

Antithamnionella ternifolia. Sterile thallus, Stilbaai. Stained slide.

Antithamnionella ternifolia. Carposporophyte, from subtidal zone, Tsitsikamma. Stained slide.

Order Ceramiales

Family Ceramiaceae

Antithamnionella tormentosa Stegenga 1986: 48, pl. 13

Plants partly creeping, attached by up to three rhizoids from the proximal cells of up to three branchlets or indeterminate laterals, sometimes developed into haptera. Erect parts to 2.5 mm tall (much larger in the type from the Western Cape), with four or five laterals including an indeterminate lateral every second segment (on creeping filaments every segment may bear an indeterminate branch). Determinate laterals variable (within a single whorl), from unbranched to provided with a short series of adaxial branchlets. Main axis to 60 µm in diameter, the cells to 170 µm long. Determinate laterals to 12 cells long, with an acute apex. Gland cells on the fourth to seventh cell, ca. 20 µm in largest diameter. Tetrasporangia sessile or stipitate, on second to fourth cell of the determinate branchlets, 50x30 µm, cruciately to tetrahedrally divided. Spermatangial stands four- or five-celled, rather straight, on all but the terminal 2-4 cells of the determinate branchlets. Up to 3 or 4 spermatangial stands per cell. Female structures not known.

Collections, ecology and regional distribution

Rare on the south coast; recorded from the Cape Peninsula to Tsitsikamma (16-32). In the Western Cape known from a number of algal substrata, and from Pyura stolonifera. The reported larger plants (Stegenga et al. 1997) were apparently only collected by Pocock.

World distribution: A South African endemic.

Type locality: Oudekraal, Cape Peninsula, Western Cape Province, South Africa (Stegenga 1986).

Antithamnionella tormentosa. 1. Part of prostrate axis with determinate branchlets. 2. Detail of erect axis with tetrasporangia. Reproduced from Stegenga et al. (1997).

Antithamnionella tormentosa. Tetrasporangial thallus, Tsitsikamma. Stained slide.

Antithamnionella tormentosa. Male thallus, Tsitsikamma. Stained slide.

Order Ceramiales

Family Ceramiaceae

Antithamnionella verticillata (Suhr) Lyle 1922: 349, figs. 5, 6

Plants partly creeping, attached by rhizoids developed from the basal cells of up to three laterals. Erect parts up to ca. 5 mm, with indeterminate laterals at intervals of 2 to 4 segments. Main axes (creeping) ca. 150 µm in diameter, the segments 2-3 times longer than broad. Segments with 4-6 rather short and more or less upright laterals. Determinate laterals unbranched or with a single branch, about 8(-10) cells long (but sometimes only 4 or 5 cells long), often with a prominent gland cell on the second cell, occasionally a gland cell on the third cell or a second gland cell on the one carrying the first; gland cells only slightly flattened, up to 30 µm in largest diameter.

Tetrasporangia usually borne singly on the basal cell of determinate branchlets, measuring 63x57 µm, tetrahedrally divided. Spermatangia not seen on south coast material; according to Stegenga et al. (1997) not different from A. ternifolia (as A. tasmanica). Carposporophytes with three (to four) gonimolobes, ripening successively. Ripe gonimolobe ca. 175 µm in diameter, carpospores ca. 35-40 µm in cross section. The thallus appears to grow on from one of the branches of the cell bearing the carposporophyte.

Collections, ecology and regional distribution

A rather common species along the whole of the Cape south coast, but so far not seen up the South African west coast west of False Bay (18-47). Epilithic, epiphytic or epizoic.

World distribution: Also recorded from Namibia (Rull Lluch 2002).

Type locality: "Kaffernk¾ste", South Africa (Silva et al. 1996).

Antithamnionella verticillata. 1. Detail of main axis and whorl-branches. 2. Tetrasporangia. Reproduced from Stegenga et al. (1997).

Antithamnionella verticillata. Sterile thallus, with gland cells. Stained slide, Mkambathi.

Antithamnionella verticillata. Tetrasporangial thallus, stained slide, Mkambathi.

Antithamnionella verticillata. Female thallus, stained slide, Mkambathi.

Order Ceramiales

Family Ceramiaceae

Bornetia repens Stegenga 1985: 163-168, figs. 1-10

Plant partly creeping, with erect filaments up to 2 cm tall. Apical cells 100-200 µm in diameter, the lower cells up to 700 µm in diameter. Cell length up to 1.5 mm. Branching (outside reproductive structures) rather infrequent, intervals varying from every second segment to several segments. Filaments ecorticate. All reproductive structures in strongly condensed systems. Tetrasporangia sessile, with a maximum of two (- three) per cell in the frequently branched system of up to 800 µm large, ca. 75-90 µm in diameter at maturity, tetrahedrally divided. Spermatangial stichidia cylindrical, with a 5- or 6-celled axis, at maturity about 200 X 80 µm, strictly one stichidum per vegetative cell; the apical (vegetative) cells much longer than in the tetrasporangial stand. Carposporangial stands with strictly a single carposporophyte, the filaments of the involucre arising in three groups, the terminal cells elongate and curving around the developing carposporophyte, the whole structure ca. 1 mm in diameter. Carposporophyte with a massive cell fusion consisting of fertile axis cell, supporting cell, gonimoblast initial and proximal gonimoblast cells. Only the terminal cells in the carposporophyte mature.

Collections, ecology and regional distribution

Recorded from Swartklip, False Bay to northern Transkei (Mkambathi)(18-48). B. repens is found on the whole of the South African south coast and in the northern half of Namibia (Rull Lluch 2002), but is apparently absent from the S. African west coast and the southern half of Namibia. B. repens is usually an epiphyte but can be epilithic.

World distribution: a southern African endemic.

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

Note: The relationship to B. tenuis from the Natal coast (Norris & Aken 1985) remains unclear.

Bornetia repens. 1. Thallus apex with clusters of antheridial heads. 2. Compact branch system with tetrasporangia. Reproduced from Stegenga et al. (1997).

Bornetia repens. Young tetrasporangial stands (stained slide material, Vleesbaai).

Bornetia repens. Tetrasporangial stands (stained slide material, Vleesbaai).

Bornetia repens. Mature carposporophyte (stained slide material, Vleesbaai).

Order Ceramiales

Family Ceramiaceae

Callithamniella Feldmann-Mazoyer

Thalli small (to a few mm tall), ecorticate, monosiphonous, axes unbranched or sparingly branched. Carposporophytes unknown, tetrasporangia pedicellate, cruciately divided. Five species currently recognised worldwide (Guiry & Guiry 2015), two of which occur on the south coast

Key to species

1a Determinate laterals unbranched, varying widely in length

Callithamniella capensis

1b Determinate laterals often with forking from the third (and fourth) cell, with little variation in length, 10 – 14 segments

Callithamniella tingitana

Order Ceramiales

Family Ceramiaceae

Callithamniella capensis Simons 1970: 6, figs 5, 6

Plants mainly creeping, the apices and laterals erect, up to 3 mm tall, often much shorter. Attachment by means of unicellular haptera developing from the first cell of the simple and compound laterals. Laterals polystichously arranged, either unbranched and up to 25 (-45) cells long, or repeating the branching of the main axis. The latter type originating at intervals of 5 of more cells, at shorter intervals when arising (later) from older segments of the already prostrate parts. Prostrate axes up to 50 (- 60) µm thick, the unbranched laterals ca. 25 µm, the cells up to ca. 115 µm long, but young segments about as long as broad or shorter.

Tetrasporangia pedicellate, single or in small clusters, usually additional to a normal lateral (single or compound) sometimes apparently replacing a lateral; sporangia cruciately divided, ca. 40-50 X 25-30 µm. Spermatangial stands additional to the normal lateral or replacing them, only little shorter than a vegetative lateral, with several segments becoming fertile, bearing ca. 5 spermatangium mother cells each with a few spermatangia. Female reproductive structure known only from one collection from East London, the carpogonial filaments formed on the basal cell of a two-celled branchlet. The post-fertilization events were not observed.

Collections, ecology and regional distribution

Found from False Bay to Haga Haga (18-43). Epiphytic and epizoic (limpet shells, Pyura tests).

World distribution: South African endemic.

Type locality: Simons Bay, False Bay, Cape Province, South Africa (Simons 1970).

Note 1. A species mainly from the south coast (the Transkei material is now determined as C. tingitana). It is close to C. flexilis Baardseth, described from Tristan de Cunha, and Athanasiadis (1996) regards the two as a single species.

Note 2. It has been remarked before that the sporangia appear to be larger on the Western Cape coast (i.e. West of Cape Agulhas): 60 X 40 µm (Stegenga 1988).

Callithamniella capensis. 1. Microscopic habit. 2 Detail of prostrate axis with base of determinate lateral, juvenile indeterminate branch, and hapteron. 3. Tetrasporangia. Reproduced from Stegenga et al. (1997).

Callithamniella capensis. Microscopic habit showing tetrasporangia. Stained slide material, Woody Cape.

Callithamniella capensis. Microscopic habit showing tetrasporangia and polystichously arranged laterals. Stained slide material, Woody Cape.

Order Ceramiales

Family Ceramiaceae

Callithamniella tingitana (Schousboe ex Bornet) Feldmann-Mazoyer 1938: 1119

Plants differentiated into a creeping part and erect axes up to 1.5 mm tall. All axes clothed in determinate and indeterminate laterals, one per segment. Determinate laterals of fairly uniform length, about 10-14 cells long, unbranched or with one or two laterals usually given off from the third (and fourth) cell, the indeterminate laterals repeating the branching scheme of the main axis. Main creeping axis about 35 (-40) µm in diameter, the cells ca. 100 µm long; determinate laterals regularly 10 -14 cells long (irrespective of branching), the cells up to 40 µm long and 15 µm in diameter, the apices tapered. Attachment by means of unicellular haptera, developed from the basal cell of both determinate and indeterminate laterals.

Tetrasporangia in (up to three) small clusters on erect parts of the thallus, sporangia with a small stalk cell, measuring ca. 45x30 µm. Spermatangia on branchlets barely smaller than vegetative ones, one or two such branchlets occurring in addition to the vegetative branch of a segment. Only the top two or three cells of a spermatangial branch remaining sterile, the other cells each with ca. 5 spermatangium mother cells. Female structures not known.

Collections, ecology and regional distribution

On our coast known only from Mbotyi and Mkambathi, Eastern Cape (47), in the latter case epizoic on a limpet and a crab shell. C. tingitana was found in the extreme east of the area and may well extend into Kwazulu-Natal.

World distribution: widespread in the Mediterranean and temperate (mainly northern) Atlantic (Guiry & Guiry 2015).

Type locality: Tangier, Morocco (Schneider & Searles 1997, cited in Guiry & Guiry 2015).

Note: Although we have long been aware that the variation in Callithamniella in South Africa warrants the recognition of more than one species, this had so far not been formalized.

Callithamniella tingitana, sterile specimen, Mkambathi (stained slide).

Callithamniella tingitana, apex of sterile specimen, Mkambathi (stained slide).

Callithamniella tingitana, sterile specimen, showing branching (stained slide).

Callithamniella tingitana, tetrasporangial specimen, Mbotyi (stained slide).

Order Ceramiales

Family Ceramiaceae

Carpoblepharis flaccida (J.V.Lamouroux) Kützing 1849: 690

Plants (on the south coast) up to 10 cm high, growing on Ecklonia radiata (on the west coast much larger and growing on Ecklonia maxima (Osbeck) Papenfuss). Basal part endophytic with a bunch of filamentous cells. Several erect axes may arise from the endophytic base. Main axis flattened, to 1(-2) mm broad, the segments consisting of a central cell, two large lateral pericentral cells and four (six in some tetrasporangium-bearing segments) smaller pericentrals in somewhat higher position. Cortication complete and in lateral direction consisting of up four cell layers, in transverse direction of up to two cell layers, exclusively developing in acropetal direction.

Tetrasporangia on all pericentral cells, the latter often increased to 8 in fertile segments. Fertile segments united in many stichidium-like proliferations on the main axes. Mature sporangia measure ca. 50 x 40 µm, tetrahedrally divided. Spermatangia on virtually all cells of proliferations of male plants being formed latest on the margins. Spermatangia ca. 10 X 5 µm. Carposporophytes lateral on proliferations (fewer on female plants than on male or tetrasporangial plants). Mature carposporophytes with several roundish gonimolobes up to 400 µm in diameter, surrounded by ca. 7 involucral filaments, the latter roundish in section, built up of central cells, (per segment 3) pericentral cells and epidermal cell layers.

Collections, ecology and regional distribution

Common from the Northern Cape through the range of Ecklonia maxima (to De Hoop), but an infrequent species on the south coast, dependent on the occurrence of Ecklonia radiata. The extension of C. flaccida is at the moment to the Transkei border (1-47), but as Ecklonia has deep-water populations to Sodwana in northern Kwazulu-Natal (De Clerck et al. 2005), an eastward extension is not improbable.

World distribution: Also recorded from Fuegia, Chile (Ramírez & Santelices 1991) and Namibia (Rull Lluch 2002).

Note: Seagrief (1988) lists only C. minima Barton for the Eastern Cape Coast. Although the size of the plants is much smaller than on the west coast, we believe that other characteristics, for instance the increase in pericentral cell number in tetrasporangial segments is closer to C. flaccida.

Carpoblepharis flaccida attached to Ecklonia frond, De Hoop (Ecklonia frond about 2 cm wide).

Carpoblepharis flaccida, De Hoop, showing stichidium-like tetrasporangial proliferations.

Carpoblepharis flaccida tip of frond, probably an immature tetrasporophyte.

Carpoblepharis flaccida, tetrasporangial (Morgan Bay, on Ecklonia radiata, stained slide).

Carpoblepharis flaccida, carposporophyte. Stained slide material.

Carpoblepharis flaccida, carposporophytes. Stained slide material.

Carpoblepharis flaccida 1. Detail of thallus with tetrasporangial proliferations. 2. Cross section of main axis. Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Ceramiaceae

Centroceras Kützing

Thallus with conspicuous large-celled central filament, each cell cutting off a ring of periaxial cells at the apical face, subsequently developing a complete cortication. Cortex consisting of remarkably straight rows of rectangular cells, developing almost exclusively in basipetal direction. In most species spines and/or gland cells developing along the apical margins of the cortical bands. Tetrasporangia borne on periaxial or (less usually) on other cortical cells, immersed or exserted, tetrahedrally divided. Spermatangia cut off from cortical cells over large parts of the thallus. Carposporophytes with an involucre of cortical filaments. (Description based on Stegenga et al. 1997).

Distinctions between species are largely based on the morphology of cortical filaments, including shape and number of acropetal cortical cells and the shape of gland cells and spines (See Won et al. 2009, 2010). Seventeen species are currently recognized (Guiry & Guiry 2015), among which five are recorded from South Africa, but the number on the south coast is unknown (see note below).

Note: Previously, Centroceras clavulatum (C. Agardh) Montagne was considered to occur throughout South Africa (Stegenga et al. 1997). This species, the type of which comes from Peru, was “often cited as being a prime example of a cosmopolitan red algal species” (Won et al. 2009). However, these authors used morphological and molecular methods to show that C. clavulatum comprises nine species, among which they recorded four (but not C. clavulatum) in South Africa. Two of the South African species were described from the west coast by Won et al. (2009): Centroceras tetrachotomum sp. nov. and C. gasparrinii (Meneghini) Kützing. Two more were described from KwaZulu-Natal by Won et al. (2010): C. hommersandii sp. nov. and C. natalensis sp. nov. A fifth species, C. distichum Okamura, was previously recorded from one subtidal locality in the Western Cape (Jackelman et al. 1991).

Both Won et al. (2009) and Won et al. (2010) based their descriptions of South African records on specimens from very few localities (usually one). Furthermore, almost all existing South African specimens were previously identified as C. clavulatum. The result is that without a detailed re-examination of existing collections (and new collections), we do not know the distribution ranges of these species, or which of them might occur on the south coast (only one south coast locality is cited for one species: C. gasparrinii, from Mzamba). Until Centroceras on the South Coast can be examined further, we provide only a description and illustrations of typical C. “clavulatum” as we previously recognized it from this region. For proper identification of South African Centroceras species, refer to Won et al. (2009) and Won et al. (2010), and particularly to the key to South African species in the latter publication.

Order Ceramiales

Family Ceramiaceae

Centroceras spp (ex “clavulatum”)

For reasons explained below (see note) we describe only specimens that were previously identified in South Africa as C. clavulatum. This description is based on Stegenga et al. (1997).

Plants up to 10 cm tall, usually smaller, bushy, dark red to almost black, consisting of many erect or partly creeping filaments, attached by several multicellular rhizoids from periaxial cells of lower segments. Plants almost dichotomously branched, with (8-)10-14(-18) segments between ramifications. Apices strongly incurved, at first the segments shorter than broad, in mature sections the segments longer than broad. Segments consisting of one big cylindrical central cell, an apical ring of 14-18(-20) periaxial cells, each of which produces three initials: 1 apical, remaining very limited in development, 1 basal, developing a cell row in basal direction, and 1 lateral, developing both a short acropetal and a long basipetal cell row. Long cell rows covering the whole of the underlying cell. Spine cells present in varying numbers, from none in plants from sheltered environment (Knysna Lagoon) to one per periaxial cell in more exposed specimens, originating from the acropetal filaments. Segments up to ca. 200 µm, up to 5 times as long as broad.

Tetrasporangia singly on the periaxial cells, at first on the “outside” of branches, later on virtually every periaxial cell per segment, completely exposed. Sporangia on the apical parts of the filaments, but also frequently on (two) adventitious branchlets, in the axils of normal branches (or rather at right angles to them). Tetrasporangia measuring ca. 70 x 55 µm at maturity, tetrahedrally divided. Spermatangia in whorls on the top of young segments, forming a closed ring ca. 25-30 µm high, individual spermatangia very small, ca. 3 µm tall. Carposporophytes with a few corticated involucral filaments, but not completely enclosed. Description based on numerous collections, covering the south coast between Still Bay and Mkambathi. See note below.

Collections, ecology and regional distribution

A common species (complex?) over the whole South African coast, from the lower intertidal to the sublittoral.

Note: Five species are now known to occur in South Africa (see Won et al. 2009, Won et al. 2010), but their distributions (other than type localities) are unknown (see note under genus Centroceras). For proper identification of South African Centroceras species, refer to Won et al. (2009) and Won et al. (2010), and particularly to the key to South African species in the latter publication.

Centroceras sp. Habit, male plant. (Stained slide, Goukamma).

Centroceras sp. Tetrasporangial. Stained slide, Kei Mouth.

Centroceras sp. Male plant. (Stained slide, Goukamma).

Centroceras sp. Detail of spermatangial stands on male plant. (Stained slide, Goukamma).

Centroceras sp. Apex of male plant. (Stained slide, Goukamma).

Centroceras sp. Tetrasporangial plant. (Stained slide, Goukamma).

Centroceras sp. Detail of tetrasporangia. (Stained slide, Goukamma).

Order Ceramiales

Family Ceramiaceae

Ceramium Roth

Plants erect or prostrate, thalli with conspicuous central filaments of globose, ellipsoid, biconical or cylindrical cells, each cutting off a ring of periaxial cells at the apical face; degree of subsequent development of cortication very variable within the genus. Number of periaxial cells 4-10. Main branching pattern varying from regularly pinnate to dichotomous, adventitious branchlets often present. Thallus apices incurved or straight. Tetrasporangia inserted on periaxial cells, less frequently also on other cortical cells. Sporangia immersed or exserted, tetrahedrally divided. Spermatangia cut off from cortical cells over large parts of the thallus. Female fertile filaments producing carpogonial filaments on several segments; carposporophytes with an involucre of corticated filaments. (Description from Stegenga et al. 1997).

Ceramium is a common genus (207 species are flagged as currently accepted taxonomically by Guiry & Guiry 2015), found in almost all marine floras. We record at least 14 species on the South African south coast, excluding those that should be assigned to Gayliella (see later). The main characters used to separate species are the pattern of nodal cortication, habit and branching pattern, incurvature of thallus apices, and tetrasporangial characters.

Note: The genus Gayliella was erected on molecular and morphological grounds (Cho et al. 2008) to include mostly former Ceramium species of the C. flaccidum complex. The main difference between the genera is that in Gayliella the cortical bands show a clear division between acropetal and basipetal cortication, with the pericentral cells giving off two acropetal and one basipetal derivatives, whereas in Ceramium the cortical bands lack a clear division between acropetal and basipetal cortication, and the pericentral cells usually give off two acropetal and two (or three) basipetal derivatives, although sometimes basipetal cortication is absent. Three former south coast Ceramium species are affected (see key below): only one, G. tranversalis, was formally transferred by Cho et al. (2008). We have placed the other two in Gayliella. The key contains both the genera Ceramium and Gayliella, but the descriptions of these three species are under Gayliella, for which we also provide a separate key.

Ceramium and Gayliella – key to species

1a. Cortical bands with a clear division between acropetal and basipetal cortication, the pericentral cells
giving off two acropetal and one basipetal derivatives (genus Gayliella)

2

1b. Cortical bands without a clear division between acropetal and basipetal cortication, the pericentral cells
usually giving off two acropetal and two (or three) basipetal derivatives, sometimes however basipetal
cortication absent

4

2a. Axes to about 50 μm in diameter, with four periaxial cells

Gayliella tranversalis

2b. Axes to 100 μm or more in diameter, with five or more periaxials

3

3a. Axes to 120 μm in diameter, segments with 5 or 6 periaxials

Gayliella dawsonii
ex
Ceramium dawsonii

3b. Axes to over 200 μm in diameter, segments with 7 (or 8) periaxials

Gayliella papenfussiana
ex
Ceramium papenfussianum

4a. Species with very conspicuous multicellular spines

Ceramium juliae

4b. Species without spines

5

5a. Cortication continuous

6

5b. Cortication discontinuous

10

6a. Main axes prostrate, mainly growing on corallines

Ceramium poeppigianum

6b. Main axes erect

7

7a. Cortication in fairly regular vertical rows

Ceramium centroceratiforme

7b. Cortication not in regular vertical rows

8

8a. Tetrasporangia completely exserted

Ceramium planum

8b. Tetrasporangia immersed

9

9a. Tetrasporangia often in short stichidium-like branchlets

Ceramium obsoletum

9b. Tetrasporangia in the apical parts of the thallus

Ceramium graecum/lenticulare

10a. Cortication in fairly regular vertical rows

Ceramium centroceratiforme

10b. Cortication not in regular vertical rows

11

11a. Each segment with a ring of very prominent gland cells

Ceramium glanduliferum

11b. Gland cells, when present, not much larger than other cortical cells

12

12a. Branching of the main axes every second segment

Ceramium callipterum

12b. Branching of the main axes at longer intervals

13

13a. Branching at intervals of 3 (occasionally 4) segments

14

13b. Branching at longer intervals

16

14a. Thallus mainly creeping, with massive rhizoid bundles

C. sp. 2

14b. Thallus (mainly) upright

15

15a. Cortication limited to 1 or 2 rows of cells, tetrasporangia completely exserted

Ceramium aff. callipterum

15b. Cortical bands broader, tetrasporangia immersed

C. sp. 3

16a. Apices of actively growing plants strongly incurved

17

16b. Apices of actively growing plants only moderately incurved or not at all

18

17a. Cortication developing in acropetal and basipetal direction to about the same extent

Ceramium arenarium

17b. Cortication developing almost exclusively in acropetal direction

Ceramium tenerrimum

18a. Apices straight, branching at intervals of 4-6(-7) segments

Ceramium graecum/lenticulare

18b. Apices moderately of slightly incurved. Branching at intervals of usually more than 6 segments

19

19a. Plants lax, winding between various seaweeds and inanimate substrata; tetrasporangia immersed.

Ceramium camoui

19b. Plants bushy, with a short (3-5 mm) apical part free from the substratum; tetrasporangia completely exserted

C. sp.1

Note: In addition to the species described here, below is a list of limited or uncertain records of species that we have not yet included, but which need further examination.

Ceramium codii (H. Richards) Feldmann-Mazoyer, Bird Island, 19-26 Aug. 1987.

Ceramium comptum Børgesen, Bird Island, 19-26 Aug. 1987.

Ceramium miniatum C. Agardh is recorded by Seagrief (1988) but we have not recognized it in the area.

Ceramium callipterum Mazoyer , Bird Island, 19-26 Aug. 198. Material probably identical to C. callipterum, not C. aff. callipterum in Stegenga et al. (1997) This specimen is branched every second segment (see Anderson & Stegenga 1989).

Ceramium fastigiatum (Roth) Harvey f. flaccidum H.E. Petersen, one specimen from Port Elizabth, one from Three Sisters.

Order Ceramiales

Family Ceramiaceae

Ceramium aff. callipterum Mazoyer 1938: 14-18, figs. 1, 2, pl. 1

Plants with a single holdfast, up to 5 mm tall, Thallus complanate, filaments branched every three (to four) segments. Main axis clear, branching to 5 orders. Cortication developing from 5 periaxial cells. Cortication in the upper section of the plants virtually absent or restricted to a few acropetal cells, later (two) basipetal cells may be cut off, or one of these is in the position of a pseudo-periaxial cell (material from the west coast, being larger, apparently shows a further development of cortication). Terminal branchlets little incurved. Internodes clear from the top of the plant, but not extending much, usually shorter than broad in all parts of the plant.

Tetrasporangia rarely more than two per segment, developing in the plane of branching, completely naked, measuring up to 62x50 µm, tetrahedrally divided. Spermatangia developing on a number of subapical segments, most abundant in the plane of branching. Carposporophytes only seen in an immature state, surrounded by three involucral filaments.

Collections, ecology and regional distribution

Epiphytic and epizoic. On the south coast only found in a deep sample off the shore of Tsitsikamma (16-32?), on Epymenia. Material from the west side of the Cape Peninsula was bigger (to 3 cm.) and had more extensively developed cortication in the older segments (Stegenga et al. 1997).

World distribution: Morocco, France Portugal, Spain (see references in Guiry & Guiry 2015).

Type locality: Mazagan (Al Kadoda), Morocco (Silva et al. 1996).

Ceramium aff. callipterum. 1-2 Thallus apex. 3-4 Older segments. 5 Tetrasporangia. Reproduced from Stegenga et al. (1997).

Ceramium aff. Callipterum, with tetrasporangia. Stained slide, specimen from 24m depth, Tsitsikamma.

Ceramium aff. Callipterum, detail of central and pericentral cells. Stained slide, specimen from 24m depth, Tsitsikamma.

Order Ceramiales

Family Ceramiaceae

Ceramium arenarium Simons 1966: 159, fig. 1:2, pl. 1:4

Plants (on the south coast) up to ca. 5 mm tall, in epilithic algal turfs, with extensive basal creeping axes. Cortication discontinuous, in apical parts with a very narrow space between cortical bands, in the creeping parts this space growing (much) longer. Cortical bands with the central cells about in the middle, upper and lower edge straight. Apices strongly incurved. Thallus dichotomously or subdichotomously branched at intervals of 6-10 cells. Attachment with several rhizoids from segments in the creeping part. Segments with 7 or 8 periaxial cells, each forming first two acropetal corticating group initials, then two basipetal corticating group initials. Periaxial cells remaining partly exposed. Axes to ca. 250 µm in diameter.

Tetrasporangia, when fully developed, in a whorl on subapical segments, remaining largely immersed, ovate, measuring ca. 65 x 45 µm at maturity, often two sporangia together on a periaxial cell. Other reproductive structures uncertain, but see Rull Lluch (2002).

Collections, ecology and regional distribution

Along the whole west coast (Stegenga et al. 1997) and the south coast as far as the East London area (1-41). A common constiutent of low, sand-binding turfs.

World distribution: Southern African endemic (also found to northern Namibia (Rull Lluch, 2002).

Type locality: Port Nolloth, Northern Cape Province, South Africa (Silva et al. 1996).

Ceramium arenarium. 1. Thallus apex. 2. Cortication in older segment. 3. Tetrasporangia. Reproduced from Stegenga et al. (1997).

Ceramium arenarium. Thallus apex. Stained slide, Woody Cape.

Ceramium arenarium. Older part with attachment filaments, stained slide.

Order Ceramiales

Family Ceramiaceae

Ceramium camoui Dawson E.Y.Dawson 1944: 319, 320, 400, 401,pl. 51: figs. 2, 3

Plants lax, creeping between other plants and inanimate substrata. Branching dichotomous at long intervals of up to 30 segments. Cortical bands distinct with straight upper and lower margins, the naked part of the central cells up to two and a half times as long as broad, in young parts often about as long as broad or slightly shorter. Plants may be attached by single rhizoids from almost any part of the plant except the very tips. Segments up to 120 µm in diameter. Apices moderately or only slightly incurved. Cortical bands with four to six or seven periaxial cells, each forming two acropetal and two basipetal cells and rarely a complete cortical tier on either side, the periaxial cells remaining visible. The west coast flora (Stegenga et al. 1997) mentions 4(-5) periaxial cells; the higher numbers were found in fertile material. In sterile specimens the diameter of the filaments often does not exceed 70 µm.

Reproductive structures seen rarely, in the present material only once (tetrasporangia). Tetrasporangia in whorls on a number of segments in rather short (adventitious) branches. Sporangia up to ca. 50x37 um, remaining inside the cortical band, causing considerable swelling of the band.

Collections, ecology and regional distribution

Occurs along the whole south coast from the Cape Peninsula to Transkei (17-47). Epilithic, epiphytic or epizoic.

World distribution: scattered warm temperate and tropical localities, including Kenya, Tanzania, Baja California, China, Queensland (Guiry & Guiry 2015).

Type locality: Isla Turners, Baja California, Mexico (Silva et al. 1996).

Ceramium camoui. 1-2 Thallus apex. 3-4 Cortication in older parts. Reproduced from Stegenga et al. (1997).

Ceramium camoui. Long sections without branching, stained slide, Mbotyi.

Ceramium camoui. Short laterals. Stained slide, Mbotyi.

Ceramium camoui. Tetrasporangia. Stained slide, Mbotyi.

Ceramium camoui. Young tetrasporangial lateral. Stained slide, Mbotyi.

Order Ceramiales

Family Ceramiaceae

Ceramium centroceratiforme Simons 1966: 164, fig. 3:3, pl. 2:3

Plants forming dense turfs throughout the littoral zone. Basal parts of the filaments attached by many rhizoids, these at first originating from the periaxial cells, later also from adjacent cells. Erect parts up to 1(-2) cm tall, maximum diameter of axis 200 (-300) µm. Thallus apices hardly incurved. Ramification subdichotomous about every 5-10 segments, few adventitious branchlets present. Cortication continuous in the apical parts, although segments remain easily distinguishable; in more basal parts cortication becoming discontinuous. Segments from shorter than broad in apical sections to a little longer than broad in more basal parts. Segments with 6 (or 7) periaxial cells, each producing two acropetal and two basipetal corticating group initials. Periaxial cells becoming completely covered. Corticating cells in fairly straight rows, in older segments basipetal cortication more extensive than acropetal cortication. Several rather inconspicuous gland cells scattered over the middle section of the cortex.

Tetrasporangia formed on the periaxial cells in subapical parts of the plants, remaining completely covered and producing no notable swelling of the individual segments, although the axis is somewhat bigger than the vegetative parts. Sporangia up to ca. 50 µm, tetrahedrally divided. Spermatangia in a continuous layer on several subapical segments, ca. 2 µm in diameter, spermatangium mother cells elongate. Carposporophytes often two on successive segments, the one or two segments below producing one or two involucral filaments. Gonimolobes rounded, to ca. 250 µm in diameter, individual carpospores ca. 15-20 µm in diameter.

Collections, ecology and regional distribution

Reasonably common, occurring between Cape Hangklip and Kei Mouth (19-43). Plants forming dense turfs in the intertidal up to high littoral (for instance, found mixed with Bostrychia intricata).

World distribution: South African endemic.

Type locality: Hermanus, Western Cape Province, South Africa (Silva et al. 1996).

Ceramium centroceratiforme. 1-2 Thallus apex. 3-5 Development of cortication. Reproduced from Stegenga et al. (1997).

Ceramium centroceratiforme. Regular cortical structure, with tetrasporangium. Stained slide, Kei Mouth.

Ceramium centroceratiforme. Stained slide, Goukamma.

Ceramium centroceratiforme. Rhizoids on lower ends of filaments. Stained slide, Goukamma.

Ceramium centroceratiforme. Carposporophyte with a few involucral filaments. Stained slide, Goukamma.

Order Ceramiales

Family Ceramiaceae

Ceramium glanduliferum Kylin 1938: 14

Plants mainly creeping, the apices up to 5 mm free from the substrate; more basal parts attached by several rhizoids per segment. Apices strongly incurved, thalli slightly unequally pseudodichotomous, main axis not distinguishable. Branching at intervals of 6-20 segments, sometimes an extra lateral given off at the first segment after a branching. Segments with 8 or 9 periaxial cells, each producing two acropetal and two basipetal cortication initials, the first acropetal one often remaining undivided and developing into a very prominent gland cell (in the rare male plants apparently absent). In mature segments the central cells completely hidden. Diameter of the filaments from 15 µm (apical cells) to 180 µm in creeping axes, the segments from much shorter than broad in the apical parts to somewhat longer, cortication incomplete, in older parts the uncorticated area increasing, both edges of the cortication fairly straight.

Tetrasporangia on a few subapical sections of the thallus, up to about four sporangia per segment, situated on the inside of forks. Sporangia completely exposed, roundish or somewhat lacrimate, measuring about 50-60 µm. Spermatangia mainly on the inside of ramifications, for several subapical sectors of the thallus, but in optima forma covering the whole segment. (Male plants doubtfully the same species, no gland cells, periaxial cells reaching the lower limit of the cortical band).

Collections, ecology and regional distribution

Occurring from Sea Point (Western Cape) into KwaZulu-Natal (16-51). Forming low turfs in the lower to mid-intertidal, often sand-binding (Stegenga et al. 1997).

World distribution: South African endemic.

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

Ceramium glanduliferum. 1-2 Thallus apex. 3. Cortication in older segments (note large gland cells). Reproduced from Stegenga et al. (1997).

Ceramium glanduliferum. Thallus apex, with gland cells, Tsitsikamma. Stained slide.

Ceramium glanduliferum. Thallus apex, with tetrasporangia, Tsitsikamma. Stained slide.

Ceramium glanduliferum (cf?). Male plant with spermatangia. Stained slide.

Ceramium glanduliferum, gland cells. Stained slide.

Order Ceramiales

Family Ceramiaceae

Ceramium graecum/lenticulare complex

Plant with a single attachment consisting of many multicellular filaments. Erect part ca. 7 mm tall, branched every 4-6(7) cells under a very narrow angle, axes more or less complanate. Apices not incurved, diameter of the thallus varying from 18 (apical cells) to over 200 µm, the segments much shorter than broad near the apices to about isodiametric in more basal parts. Segments with a prominent central cell, 7 or 8 periaxial cells, each with (up to) 2 acropetal and 2 basipetal corticating initials, often with very limited development of further cortication. Cortical bands often touching each other in the plane of branching of the plant, but leaving a large part of the central cell exposed in the plane perpendicular to it. Tetrasporangia in a number of subterminal segments, only developing in the plane of branching, remaining enclosed in cortical tissue, final size probably some 50 µm in diameter (empty sporangia).

Collections, ecology and regional distribution

Only recorded from a collection at Xora River, Transkei, at 16-20 m depth.

Note: this is one of several Ceramium entities for which we have very limited material, and the affinities of which are unclear.

Ceramiun graecum/lenticulare complex, with tetrasporangia. Stained slide.

Ceramiun graecum/lenticulare complex, showing cell arrangement at nodes. Stained slide.

Ceramiun graecum/lenticulare complex, showing detail of cell arrangement at nodes. Stained slide.

Order Ceramiales

Family Ceramiaceae

Ceramium juliae A.J.K.Millar 2002

Plants small, specimens found not over 5 mm, completely pressed against the substratum. Thalli subdichotomously branched at intervals of 4-6(-8) segments, attached by bundles of rhizoids from the segments producing a lateral, although in older parts other segments may produce a few rhizoids too. Apices strongly incurved, the outer “wings” already developing before the opposite periaxial cells even are formed. Segments with six periaxial cells (8 when producing a lateral), the two lateral periaxial cells being much larger than the ones in cross positions. On all periaxials a spine is produced, the two in the plane parallel to the substrate terminal on a massive “wing”, the four others a much smaller uniseriate spine ca. 3 or 4 cells long. All spines with a sharp-pointed apex, the large wings usually with a few spines (often two or three-celled) on the acropetal surface too. All periaxial cells produce three derivatives, the ones in lateral position one on either side, the massive wing being the third one; the ones across in positions straight above and below and one lateral, the latter producing an upward and downward derivative and developing into a pseudo-periaxial cell; the spines from these corticating groups are produced from the apical corticating initial. Fertile material not seen.

Collections, ecology and regional distribution

Recorded from Stilbaai to Trafalgar on the southern KwaZulu-Natal coast (26-48). Subtidal and intertidal, sometimes washed ashore attached to deeper subtidal seaweeds (Stirk & Aken 1993).

World distribution: the only other records are from eastern Australia (Millar 2002).

Type locality: eastern Australia (Millar 2002).

Note: Fairly recently described from Australia (Millar, 2002); South African specimens show no difference in structure. The species was mentioned but not formally described by Stirk & Aken (1993) and has been known from South Africa since the mid 1980’s.

Ceramium juliae, Tsitsikamma.

Ceramium juliae, Tsitsikamma, detail of cell structure.

Order Ceramiales

Family Ceramiaceae

Ceramium obsoletum C. Agardh 1828: 145

Plants on the south coast usually a few cm tall, on the west coast to 20 cm (Stegenga et al. 1997). Usually epiphytic, sometimes the base endophytic, but no creeping parts present. Thallus branched in one plane, number of segments between ramifications varying between 6 and 20, angle between ramifications apparently increasing with age, branches growing together for a segment (and a half). Apices tapering strongly, slightly or not incurved or even bent outward (tetrasporiferous branchlets). Axes up to 700 µm in diameter, the segments slightly shorter than broad. ca. 9 or 10 periaxial cells, producing a small-celled cortex; different cortical bands not discernable. Periaxials producing 2 acropetal and 3 basipetal corticating initials.

Reproductive structures of any kind often on numerous small (ramified) branchlets in unilateral series on the main axes. Fertile branchlets more frequently branched, often at intervals of 4 segments. Tetrasporangia in whorls on the small branchlets, remaining completely covered by the epidermis, up to 80 x 62 µm, sometimes in more elaborate branched systems near the apices of the plant, with the sporangia mainly in opposite positions in the plane of branching. Spermatangia covering all but the apical-most segments of small branchlets. Carposporophytes in low numbers on female branchlets, with ca. two or three gonimolobes and ca. seven involucral filaments; carpospores ca. 45 µm in cross section, in perfectly round carposporophyte of about 250 µm diameter.

Collections, ecology and regional distribution

Occurring over the whole south coast, although significantly smaller than on the west coast. Extending as far eastwards as the Durban area of KwaZulu-Natal (1-51).Usually epiphytic on larger seaweeds.

World distribution: also recorded from Namibia and Brazil (Guiry & Guiry 2015).

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

Ceramium obsoletum. 1 Thallus detail with tetrasporangial “stichidia”. 2 Thallus apex. 3 Cross section of mature segment (through periaxial cells). 4 Tetrasporangia. Reproduced from Stegenga et al. (1997). 

Ceramium obsoletum. Carposporophyte, stained slide material, Dome Bluff, Transkei.

Ceramium obsoletum. Tetrasporophyte, stained slide material, Dome Bluff, Transkei.

Ceramium obsoletum. Detail of tetrasporangia, stained slide material, Dome Bluff, Transkei.

Ceramium obsoletum. Fresh specimen, Tsitisikamma.

Order Ceramiales

Family Ceramiaceae

Ceramium planum Kützing 1849: 687

Plants on the south coast at the most a few cm tall (on the west coast up to 20 cm: Stegenga et al. 1997). Plants with a percurrent main axis, giving off laterals at intervals of 3 or 4 segments, strictly alternating and in one plane, re-branching several times; adventitious branchlets frequent. Plants without creeping parts. Thallus apices only slightly incurved. Main axis up to 400 µm in diameter (up to 1 mm on the west coast). Segments with on average six periaxial cells, each forming four or five derivatives, developing a full cortication (except for leaving a bare spot on the non-branching sides), about the same in acropetal and in basipetal direction. Central cells at maturity about twice as long as broad, somewhat constricted in the middle. Tetrasporangia completely exerted, mainly developing in the plane of branching of the plant, but at maximum development in a full circle. Tetrasporangia at maturity ca. 50 x 42 µm, tetrahedrally divided. Spermatangia developing on several sub-ultimate branches, mainly in the plane of branching.

Collections, ecology and regional distribution
C.planum is primarily a west coast species extending into, but seen only rarely on the south coast Our (rare) records extend as far east as Bird Island (1-38). An epiphyte on larger seaweeds in the subtidal.

World distribution: Also recorded from Namibia (Rull Lluch 2002) and Antarctica (Papenfuss 1964). The alleged occurrence in Mozambique (Silva et al. 1996) is to be regarded with caution.

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

Ceramium planum. 1-2 Thallus apex. 3-4 Cross section of mature segments (in 3 showing periaxial cells). 5 Tetrasporangia. Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Ceramiaceae

Ceramium poeppigianum Grunow 1868 '1867': 64, pl. VIII: fig. 2

Plant creeping on the host species (usually Amphiroa spp.), main axes up to a few cm long with one or two more or less regular rows of laterals of limited development. Axes attached to the substratum by massive bundles of rhizoids given off by the epidermis at intervals of 5-10 segments (sometimes on a few contiguous segments), usually from the main axes, but occasionally also from some proximal segments of the laterals. Apices straight. Usually cells of the main axis with eight periaxial cells, the two lateral ones giving off a side branch and then larger than the other periaxial cells. Cortication developing from two acropetal and three basipetal cells per periaxial cell, the acropetal cortication developing first. Cortication complete, with little variation of cells size, the periaxial cells completely covered. Main axes to ca. 200 µm in diameter.

All reproductive organs developing only on the laterals. Tetrasporangia completely immersed, often two sporangia of different age on one periaxial cell, up to twelve per segment. Sporangia measuring ca. 60 x 45 µm at maturity and more or less cruciately divided. Spermatangia covering the top half of the laterals. Carposporophytes seemingly apical on laterals, covered by ca. seven involucral filaments. Gonimoblasts up to three per carpopsporophyte, with spores to 40 µm in diameter.

Collections, ecology and regional distribution

A fairly common species, especially in the eastern half of the area; records extend from Still Bay to Mission Rocks/Cape Vidal in KwaZulu-Natal (26-56). An epiphyte of Amphiroa bowerbankii and A. ephedraea

World distribution: Outside South Africa, known from the Cape Verde Islands (Price et al. 1986).

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

Note: The species has been studied in detail by Hommersand (1963).

Ceramium poeppigianum. Tetrasporophyte (on Amphiroa ephedraea), stained slide material, Double Mouth.

Ceramium poeppigianum. Detail of tetraspororagia, stained slide material, Double Mouth.

Ceramium poeppigianum. Male plant, seen from below, with regularly-spaced rhizoidal bundles. Stained slide material, Double Mouth.

Ceramium poeppigianum. Carposporophytes. Stained slide material, Double Mouth.

Order Ceramiales

Family Ceramiaceae

Ceramium sp 1

Plants caespitose, the apices for 3-5 mm erect and free from the substrate. Filaments dichotomously branched ca. every 12-15 segments, the apices moderately incurved. Cortical bands with straight upper and lower margin, usually not wider than 5 cell rows. Inter-cortical spaces stretching to three times their diameter in the horizontal parts of the thallus. Filaments becoming 120 (-150) µm in diameter. Segments with 6-7 pericentral cells remaining largely exposed and cutting off two acropetal corticating initials and two basipetal ones. Several prominent gland cells in the acropetal cortex, measuring up to 20x12 µm. Rhizoids originating from the pericentral cells, becoming multicellular. Tetrasporangia completely exserted, mainly on the inside of forkings in the subapical regions, sporangia nearly globose, measuring ca. 50x45 µm at maturity, with a tetrahedral division.

This species seems to be related to C. glanduliferum, but is smaller, has fewer pericentral cells, more modest incurvature of the apices and less extensive development of cortex.

Collections, ecology and regional distribution

Only known from Mkambathi (47).

World distribution: unknown.

Ceramium sp. 1. Stained slide material.

Order Ceramiales

Family Ceramiaceae

Ceramium sp 2

Plants largely creeping, attached by massive bundles of rhizoids emitted every third node of the main axis, only the top part for ca. 2 mm free from the substrate. Thallus largely complanate, branched every third segment, the laterals regularly alternating. Apices hardly incurved, older branches rather pointed. Axes ca. 100 µm in diameter, broader when tetrasporangia are present. Segments with six periaxial cells, these at first forming two acropetal cells and a further row of corticating cells, before forming an additional two basipetal corticating cells. Older segments with several corticating rows, both acropetal and basipetal, the cortical bands with straight upper and lower border, the uncovered part of the central cells in the creeping main axis longer than broad. Rhizoids formed every third segment of the main axis, virtually each cell of the cortex directed towards the substratum, cutting off a rhizoid. Mature rhizoids in tight bundles, with a broad cell cut off at the apex of each rhizoid. Tetrasporangia mainly formed in the plane of branching, measuring ca. 62x42 µm, cruciately divided, remaining covered by corticating cells. Spermatangia covering a number of subapical segments. Carposporophytes with 2-3 round gonimolobes of various ages, the largest ca. 150 µ in diameter, individual carpospores ca. 25 µm across. On average six involucral filaments present.

Collections, ecology and regional distribution

Found as an epiphyte on Ecklonia radiata and Anthophycus longifolius, so far only found in the Kei region and Mkambati (43-47).

World distribution: unknown.

Ceramium sp. 2, bearing carposporophytes. Stained slide material, Mkambathi.

Ceramium sp. 2. Creeping basal axis with uprights and attachment rhizoid bundles. Stained slide material, Mkambathi.

Ceramium sp. 2, tetrasporangia, Kei Mouth.

Ceramium sp. 2, detail of tetrasporangia. Stained slide material, Mkambathi.

Ceramium sp. 2, male thallus. Stained slide material, Mkambathi.

Ceramium sp. 2. Detail of a rhizoidal bundle on a basal axis (centre), Kei Mouth.

Order Ceramiales

Family Ceramiaceae

Ceramium sp 3

Plants to (2 cm) tall, with only basal attachment, no creeping filaments present. Thallus largely complanate, branching every third segment, the laterals regularly alternating. Axes up to 300 µm in diameter, segments with six periaxial cells present, at first with two acropetal cells cut off, the periaxial cells staying in basal position in the cortical band for some time. Finally three basipetal cells are cut off and the periaxial cells appear to move to a deeper level, although they remain perfectly visible. Cortical bands with straight upper and lower border, inter-cortical spaces remaining shorter than broad. Only tetrasporangia found as reproductive structures, in whorls on several subapical segments. Sporangia measuring ca. 45x37 µm, cruciately divided, remaining covered by corticating cells.

Collections, ecology and regional distribution

Material epiphytic on Plocamium corallorhiza, only found at Mkambati (47).

World distribution: unknown.

Ceramium sp. 3, tetrasporangial. Stained slide material, Mkambathi.

Ceramium sp. 3, detail of tetrasporangia. Stained slide material, Mkambathi.

Order Ceramiales

Family Ceramiaceae

Ceramium tenerrimum (G. Martens) Okamura 1921: 112, pl. CLXXIX: figs 1-7

Plants to a few cm tall, partly creeping and attached by one to several rhizoids per segment, these unicellular and derived from the periaxial cells. Apices strongly incurved. Segments with six or seven periaxial cells that produce two acropetal derivatives and one (or two) to the side, the cortication remaining of limited development and the periaxial cells reaching the lower limit of the cortical band even in mature segments. In older segments the uncorticated part longer than the cortical band. Axes up to 500(-750) µm in diameter, the segments up to twice as long. No percurrent main axis present, the branching subdichotomous at intervals of 8 to 20 segments. Rather small and inconspicuous gland cells present in a subapical zone of the cortex.

Tetrasporangia in whorls on many segments from the upright parts, causing considerable swelling of the segment but remaining largely covered by the epidermis. Sporangia measure up to 75 x 50 µm, and are cruciately to tetrahedrally divided. Spermatangia covering mainly the inside of branches of many subapical segments. Female structures not seen.

Collections, ecology and regional distribution

Found along the whole west coast, but recorded only as far as Tsitisikamma on the south coast (1-32). A reasonably rare species in the western half of the south coast, epilithic in algal turfs.

World distribution: also recorded from Taiwan but believed to be widespread in tropical areas (Stegenga et al. 1997).

Type locality: Nagasaki, Japan (Martens 1866).

Ceramium tenerrimum. 1-2 Thallus apex. 3 Cortication in older segment. Reproduced from Stegenga et al. (1997).

Ceramium tenerrimum. Tetrasporangial specimen, Walker Point (Goukamma). Stained slide material.

Ceramium tenerrimum. Sterile specimen, Walker Point (Goukamma). Stained slide material.

Ceramium tenerrimum. Detail of tetrasporangial specimen, Walker Point (Goukamma). Stained slide material.

Order Ceramiales

Family Ceramiaceae

Compsothamnionella sciadophila Stegenga 1990: 94-98, figs. 1, 2

Plants up to a few cm tall, with in principle one erect axis, but basal-most segments often with a number of indeterminate laterals. Holdfast consisting of many multicellular rhizoids. ‘Erect’ axes spreading more or less parallel to the substrate. Main axis up to 200 µm in diameter, tapering to ca. 15 µm in the apical cells, branching alternately, strictly in one plane; ramification to the fifth order, in principle from every cell. Cells throughout the plant about as long as broad. The older segments of the main axis develop an incomplete cortication as a rhizoidal branch from the basal cell of a lateral connects with the (higher-order) lateral from two segments below.

Tetrasporangia develop on one side (the upper side) of the erect axes, on the final ramifications; they measure up to 45 µm in diameter, being perfectly globular and tetrahedrally divided. Occasionally a (slightly larger) octosporangium is found. Male stands conical, with a 5-10-celled central axis, on the terminal or subterminal-order branchlets. Female stand developing subterminally on third and fourth order branchlets, the procarp situated on the second to fifth cell below the apex. Carposporophyte several subglobose gonimolobes, surrounded by a number of branched involucral filaments originating from the cells below the fertile axial cell.

Collections, ecology and regional distribution

Recorded from False Bay to the East London area (17-41). An inconspicuous, though not uncommon member of (shaded) algal communities in lower intertidal rock pools. Grows as an epiphyte on a variety of algae, but apparently can occur also on lifeless substrata.

World distribution: South African endemic.

Type locality: Three Sisters, Eastern Cape, South Africa (Stegenga 1990).

Compsothamnionella sciadophila 1.Thallus apex. 2 Tetrasporangia. Reproduced from Stegenga et al. (1997).

Compsothamnionella sciadophila , thallus with tetrasporangia. Stained slide specimen, Walker Point (near Goukamma).

Compsothamnionella sciadophila , tetrasporangia. Stained slide specimen, Walker Point (near Goukamma).

Compsothamnionella sciadophila , older axes with “cortical filaments” connecting laterals. Stained slide specimen, Walker Point (near Goukamma).

Order Cermiales

Family Ceramiaceae

Episporium centroceratis Möbius 1885: 77-80, pl. 7

Thalli parasitic on Centroceras; visible when mature as colourless pustules up to 500 µm in diameter, usually just above nodal rings on host axes. Mature thalli roughly hemispherical, cushion-like, comprising repeatedly-branching rows of cells radiating from a central cell that is attached to the host. Base of central cell penetrating cortex of host and attaching to axial cell of host. Reproductive structures arising in outer layers of pustule. Tetrasporangia cruciately divided, prolifically scattered over surface. Sexual pustules monoecious or dioecious; spermatangia covering surface or mixed in patches with cystocarps. Cystocarps roughly hemispherical, with numerous trichogynes when young, scattered over surface of pustule. For a detailed description and illustrations see Pocock (1956).

Collections, ecology and regional distribution

Pocock recorded this species from localities between Port Elizabeth and Isipingo, south of Durban (36-51). It is an obligate parasite on Centroceras, but not common, and generally found on older (short, stunted) specimens of the host (Pocock 1956: “when found on a single tuft of the host usually present in fair numbers...”).

World distribution: Otherwise recorded only from the type locality in Western Australia.

Type locality: Dirk Hartog Island, Western Australia (Pocock 1956).

Note: In her detailed study of this species, Pocock (1956) expressed some doubt that it belongs to the Ceramiales and discusses its possible affinities with other red algal orders.

Episporium centroceratis. 1 Young pustule with numerous trichogynes in various stages of development. Note narrow band of spermatangia low on the cushion. 2 Mature pustule with developing cystocarps, trichogynes and spermatangial areas. Re-drawn from Pocock 1956, Fig 2 e and f).

Episporium centroceratis. 1 Part of section of pustule showing developing tetrasporangia and two empty sporangial walls. Tetrasporangia illustrated on right. 2 Developing pustule showing attachment organ at base, and numerous nuclei in central cell. Re-drawn from Pocock 1956, Figure 2 a and b and Figure 1n.

Order Ceramiales

Family Ceramiaceae

Gayliella T.O.Cho, L.J.McIvor & S.M.Boo 2008

Plants epiphytic, with prostrate and erect portions, attached by rhizoids, corticated only at nodes, alternately branched, apices claw-like. Three cortical initials produced per pericentral cell, two directed towards the apex and one towards the base. Corticating rhizoids unicellular, arising from pericentral cells and ending in a digitate tip. Cystocarps near apices, with surrounding involucral branches; tetraporangia single, arising only from pericentral cell; antheridia arising from cortical cells.

Most species of Gayliella were formerly ascribed to Ceramium (C. flaccidum complex), but were separated on molecular and morphological grounds (Cho et al. 2008). The main difference between the genera is that in Gayliella the cortical bands show a clear division between acropetal and basipetal cortication, with the pericentral cells giving off two acropetal and one basipetal derivatives, whereas in Ceramium the cortical bands lack a clear division between acropetal and basipetal cortication, and the pericentral cells usually give off two acropetal and two (or three) basipetal derivatives, although sometimes basipetal cortication is absent.

Key to species

1a. Axes to about 50 μm in diameter, with four pericentral cells

Gayliella transversalis

1b. Axes to 100 μm or more in diameter, with five or more pericentrals

2

2a. Axes to 120 μm in diameter, segments with 5 or 6 pericentrals

Gayliella dawsonii

2b. Axes to over 200 μm in diameter, segments with 7 (or 8) pericentrals

Gayliella papenfussiana

Order Ceramiales

Family Ceramiaceae

Gayliella dawsonii = Ceramium dawsonii A.B. Joly 1957: 150-152, pl. XIX: figs. 1, 1a, 1b, 1c, 1d ('dawsoni')

According to the morphological criteria of Cho et al. (2008), this species should belong to Gayliella, but no formal transfer has been made.

Plants partly creeping, with erect part up to 2 cm but often smaller, the creeping parts attached by up to three rhizoids per segment, arising from the periaxial cells. Apices moderately to little incurved. Thallus alternately branched at intervals of 3-6 segments, diameter varying for 20 µm (apex) to 120 µm. Segments with 5-6(-7) periaxial cells, each producing two acropetal and one basipetal corticating group initials, periaxial cells remaining partly exposed. Cortication usually limited to two (horizontal) rows basipetally and three rows acropetally, the two separated strictly. Cortication incomplete, the uncorticated part of the central cells shorter than broad in young parts of the thallus, much longer in basal (creeping) parts. Acropetal cell groups sometimes with a few gland cells.

Tetrasporangia borne by periaxial cells, ca. 45 µm in length, tetrahedrally divided, largely immersed in the cortex, causing considerable swelling of the segment. Spermatangia on subapical sections of the thallus. Carposporophytes small, consisting of one or two gonimoblasts with few (about 10) spores up to 40 µm in diameter. Involucral filaments about six.

Collections, ecology and regional distribution

A very common species over the whole of the south coast from False Bay eastward (17-56 ) as well as from Namibia and Natal (as Ceramium flaccidum – Rull Lluch 2002, De Clerck et al. 2005 – see note below). The material is known from a wide variety of substrata, mostly other algae.

World distribution: Caribbean, Atlantic South America (references cited in Guiry & Guiry, Nov 2015), but see note below.

Type locality: Paranapoan, Brazil (Silva et al. 1996).

Note: The precise relationship of C. flaccidum to the present species (and C. papenfussianum from the west coast) remains to be established. C. flaccidum is typified by a specimen from south-west England and grows up to 12 cm tall and has internodes 8-12 times as long as broad (Maggs & Hommersand 1993). Descriptions of southern African material agree on a maximum size of 2 cm of the upright parts (De Clerck et al. 2005, Rull Lluch 2002), the maximum observed length of the internodes is 5 times the diameter.

Gayliella dawsonii (= Ceramium dawsonii, see note). 1. Microscopic habit. 2. Detail of older segments. 3. Thallus apex. Reproduced from Stegenga et al. (1997), as Ceramium dawsonii).

Order Ceramiales

Family Ceramiaceae

Gayliella papenfussiana ( = Ceramium papenfussianum Simons 1966: 159, fig. 2; pl. 2:1)

According to the morphological criteria of Cho et al. (2008), this species should belong to Gayliella, but no formal transfer has been made.

Plants up to at least 1.5 cm tall, with a strongly percurrent main axis, giving off laterals at intervals of 4-5 segments. Thallus apices only little incurved. Diameter of main axis to over 200 µm, the segments in mature parts stretching to ca. 600 µm, or 4 times the diameter, mainly naked, the corticating bands remaining relatively narrow, with straight upper and lower limit. Segments with 7(-8) periaxial cells, each producing two acropetal and one basipetal corticating initial, with a fairly strict separation of acropetal and basipetal cortication, the periaxial cells remaining partly exposed. Acropetal cortication about three cell layers, usually with a number of prominent gland cells (about one for each periaxial cell). Basipetal cortication about two cell layers.

Tetrasporangia in a number of subapical segments, in optimal development one per periaxial cell, completely immersed, tetrahedrally divided, measuring ca. 50x40 µm, causing considerable swelling of the segment. Tetrasporiferous segments hardly develop the basipetal cortication.

Collections, ecology and regional distribution

Gayliella/Ceramium papenfussianum is primarily a west coast species and appears rare on the south coast (1-48). It differs from the partly overlapping G. dawsonii by the larger diameter of the main axis and the higher number of periaxial cells. (Both species have not formally been transferred to the genus Gayliella).

World distribution: South African endemic.

Type locality: Sea Point, Cape Town, South Africa (Silva et al. 1996).

Gayliella papenfussiana. 1. Microscopic habit (tetrasporangial). 2. Older segments (note gland cells). 3.Tetrasporangia. reproduced from Stegenga et al. (1997) (as Ceramium papenfussianum).

Gayliella papenfussiana ( = Ceramium papenfussianum)  with tetrasporangia. Stained slide material, Tsitsikamma.

Gayliella papenfussiana (= Ceramium papenfussianum),  cortex in older segments. Stained slide material, Tsitsikamma.

Gayliella papenfussiana (= Ceramium papenfussianum),  cortex in older segments, different level. Stained slide material, Tsitsikamma.

Order Ceramiales

Family Ceramiaceae

Gayliella transversalis (Collins et Hervey) T.O. Cho et Fredericq in Cho et al. 2008: 727, figs 5, a-n; 6, a-e

Plants minute, partly creeping, with erect parts to a few mm tall, the creeping part longer. Thallus branched alternately every 5-10 segments. Apices little incurved. Segments with four pericentral cells, each producing two upward-corticating initials, one basipetal initial. Cortication remaining very limited, with usually two acropetal layers and two basipetal layers, with a clear separation. The central cells stretching to several times their diameter. Axis to about 50 µm thick, segments at first a little shorter than broad, later to 500 µm long or 10 times as long as broad. Rhizoids one or two per segment, unicellular, arising directly from the periaxial cells. Tetrasporangia up to two (to three) per segment, largely covered by corticating filaments, roundish, measuring ca. 40 µm. Other reproductive material not seen.

Collections, ecology and regional distribution

On the south coast found only in eastern Transkei (47), epiphytic on Amphiroa ephedraea; other species of the genus Gayliella have a more western distribution.

World distribution: scattered records from warm temperate and tropical locations.

Type locality: Spanish Rock, Bermuda (Silva et al. 1996).

Material (HS): Mkambati, 7-10-2002: EC1712 (on Amphiroa ephedraea).

Note: . Formerly known as Ceramium byssoideum, a name no longer available for this entity (Silva et al. 1996).

Gayliella transversalis, Mkambathi. Stained slide material.

Gayliella transversalis, cell detail, Mkambathi. Stained slide material.

Gayliella transversalis, Mkambathi, creeping filament with attachment rhizoids. Stained slide material.

Order Ceramiales

Family Ceramiaceae

Laurenciophila minima Stegenga 1986: 130, pl. 47

Plants semi-endophytic in various Laurencia spp., the basal cell strongly enlarged to ca. 300 X 200 µm, together with a second (much smaller) cell forming the endophytic base. The emergent part of the plant up to ca. 1 mm tall, filamentous, ecorticate, irregularly branched with one to three laterals per cell. Cells up to 40 µm in diameter, once to twice as long, apical cells 7-8 µm broad. The branches somewhat incurved.

Tetrasporangia in small clusters, developing on a single cell near the base of branches; sporangia almost spherical, ca. 45 µm in diameter at maximum. Male plants, according to earlier description (Stegenga et al. 1997) with male stands very small and of simple construction. Carposporophytes with a number of short but clear filaments of carpospores, individual spores measuring up to ca. 30 µm in diameter. The sexual reproduction of this small semi-endophyte has been described in more detail (Stegenga, 1988). Infection of the host apparently takes place right at the apex of the plant where spores enter through the gaps in the epidermis where trichoblasts emerge.

Collections, ecology and regional distribution

Recorded from False Bay to Port Alfred (17-39). Endophytic in Laurencia spp.

World distribution: South African endemic.

Type locality: Cape Infanta, Western Cape Province, South Africa (Stegenga 1986).

Laurenciophila minima. 1 Habit, showing large endophytic base cell. 2 Tetrasporangia. Reproduced from Stegenga et al. (1997).

Laurenciophila minima. Habit, on Laurencia flexuosa. Tsitsikamma, stained slide.

Laurenciophila minima. Detail with tetrasporangia. Tsitsikamma, stained slide.

Laurenciophila minima. Large endophytic basal cell and emergent main axis. On Laurencia flexuosa, Tsitsikamma. Stained slide.

Order Ceramiales

Family Ceramiaceae

Microcladia Greville

Thalli erect, terete to compressed, corticated, branched in alternate to pectinate pattern, branch apices forcipate. Gland cells present in south coast species. Tetrasporangia exserted in south coast species, tetrahedrally divided. Carposporophytes surrounded by involucral filaments.

Ten species are currently recognised worldwide (Guiry & Guiry 2015), of which two occur on the south coast.

Key to species

1a. Species growing mostly on Corallines; main axis up to 500 µm thick, appressed against the substratum

Microcladia exserta

1b. Species growing mostly on Gelidium; main axis up to 1 mm thick, erect

Microcladia gelidii

Order Ceramiales

Family Ceramiaceae

Microcladia exserta M.J.Wynne 1985: 1930199, figs. 1-23

Plants up to a few cm long, epiphytic on and flat against the substratum (as a rule articulated Corallines, especially Amphiroa species). Axis regularly alternately branched every three of four segments, the apices of main axes and laterals moderately incurved. Axis completely corticated, separate cortical band hardly distinguishable, but growing in acropetal direction, becoming more than one cell layer thick. Gland cells in the epidermis very numerous, roughly in a band per main axis cell, but sometimes much more abundant. Main axes up to 500 µm broad, central cells up to 200 µm.

Tetrasporangia completely exserted, on the apical sections of the laterals, abundant in the plane of branching, several per segment being present. Sporangia measuring ca. 60 x 21 µm and tetrahedrally divided. Male plants not seen. Carposporophytes developing close to the apices of laterals, at maturity with one or two roundish gonimoblasts ca. 250 µm in diameter, the individual carpospores ca. 35 µm in largest diameter. Carpospopophyte surrounded by about six involucral filaments of the same structure as young vegetative branches.

Collections, ecology and regional distribution

Found between Stilbaai and central KwaZulu-Natal (26-51). Epiphytic on larger seaweeds, usually articulated corallines (e.g. Amphiroa ephedraea).

World distribution: South African endemic.

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

Note: this species was described from KwaZulu-Natal (Wynne, 1985).

Microcladia exserta, on Amphiroa ephedraea, Dome Bluff (herbarium specimen).

Microcladia exserta, thallus detail. Specimen from Dome Bluff (stained slide).

Microcladia exserta, with tetrasporangia. Specimen from Dome Bluff (stained slide).

Microcladia exserta, detail showing central cells. Specimen from Dome Bluff (stained slide).

Order Ceramiales

Family Ceramiaceae

Microcladia gelidii R.H.Simons 1967: 352, fig. 1; pls 1, 2

Plants epiphytic on a variety of larger seaweeds (usually Gelidium spp), up to 7 cm tall, axes strictly branched in one plane, about every 5-7 segments, laterals usually of limited growth. Young apices somewhat curved inward. Main axis to over 1 mm broad, the central axis up to 400 µm broad, with (in the plane of branching) up to 4 layers of cortication. Separate cortical bands indistinguishable, growing in acropetal direction. Gland cells not as numerous and not as striking as in M. exserta, still may be amply present in roughly one girdle per central cell.

Tetrasporangia on side branches and on numerous proliferous branchlets present in the axils between main axis and branches, mainly on the “inside” of the moderately bent branchlets. Sporangia completely exserted, measuring ca. 50 x 45 µm, tetrahedrally divided. Spermatangia on a number of subapical segments of the side branches and adventitious branchlets, mainly covering the “inside” of the branchlets. Spermatangia formed terminalyl on elongate spermatangium mother cells. Carposporophytes on subapical segments of side branches, consisting of two or three roundish gonimolobes, at maturity ca. 200 µm in diameter, the carpospores ca. 35 µm broad. Carposporophytes surrounded by ca. seven involucral filaments.

Collections, ecology and regional distribution

Recorded from Woody Cape to the east of Transkei (31-48). The species does not seem to overlap with M. gloria-spei Stegenga, which grows on the west coast and in Namibia and attains much larger dimensions (Rull Lluch 2002).

World distribution: South African endemic.

Type locality: Port St. Johns, Transkei, South Africa (Silva et al. 1996).

Microcladia gelidii, on Zonaria subarticulata, Morgan Bay (herbarium specimen).

Microcladia gelidii, thallus detail with carposporophytes, Mkambathi (stained slide).

Microcladia gelidii, thallus detail with tetrasporangia, note central cells (stained slide).

Microcladia gelidii, with tetrasporangia (stained slide).

Order Ceramiales

Family Ceramiaceae

Perischelia glomulifera (J.Agardh) J.Agardh ex Kylin 1956: 397, fig. 311B

Thallus red, stringy and flaccid, up to 30 cm long, branched, heavily corticated, with branches (usually) beset with short glomuliferous tufts. Tufts on short lateral branches, bearing a few to many determinate, alternately pinnate branchlets, 1-2 mm wide and long, borne on short stalks. Holdfast a disc. One specimen in BOL appears devoid of glomuliferous tufts, a condition seen is some branches of another more typical specimen. Reproduction unknown.

For further details see Womersley (1998).

Collections ecology and regional distribution

Recorded from Struisbaai to Morgan Bay (23-43). Rarely found, apparently in drift, and it may be a deeper-water species.

World distribution: First described from Australia (see Womersley 1998).

Type locality: Port Phillip Heads, Victoria (Womersley 1998).

Perischelia glomulifera, drift specimen from Struisbaai (herbarium specimen).

Perischelia glomulifera, detail of drift specimen from Struisbaai (herbarium specimen).

Perischelia glomulifera, drift specimen from Riet River, near Port Alfred (herbarium specimen). Note absence of glomuliferous tufts.

Order Ceramiales

Family Ceramiaceae

Pterothamnion Nägeli

Thallus erect, filamentous, (generally) ecorticate, with main axis of relatively large cells giving rise to determinate laterals and lateral axes of indeterminate growth. Each axial cell bearing two opposite branches, or with one or two additional branches in a whorl. Branches simple or re-branched up to the fourth order. Gland cells may be present. For a detailed description, see Athanasiadis & Kraft (1994). Worldwide, 28 species are currently recognized (Guiry & Guiry 2015). We tentatively recognize two species on the south coast, but the genus is rare here and we have few specimens. 

Note: the genus Pterothamnion now includes the former genera Platythamnion and Glandothamnus (see Athanasiadis & Kraft 1994). The species of Platythamnion that we had recorded on our west coast (Stegenga et al. 1997) and south coast are therefore now placed in Pterothamnion.

Key to species

1a. The (proximal) cells of the whorl branchlets each with one ramulus

Pterothamnion sp.

1b. The (proximal) cells of the whorl branchlets each with two ramuli

Pterothamnion recurvatum

Order Ceramiales

Family Ceramiaceae

Pterothamnion recurvatum (Wollaston) Athanasiadis & Kraft 1994: 130

Plants up to 2 cm tall, alternately branched at intervals of 3-5 segments; indeterminate laterals replacing a major whorl branchlet. Main axis up to 250 µm in diameter, the cells 1-2 times as long as broad. Major whorl branchlets up to 500 µm long, the proximal cells each with two dorsal pinnules, the latter re-branched adaxially. Branchlets strongly recurved; apices of all ramuli acuminate. Minor whorl branchlets smaller, about equivalent to a pinnule of a major branchlet. Gland cells numerous and rather prominent, usually on the fourth or fifth cell from the apex of the ultimate ramuli. Tetrasporangia singly sessile or in small pedicellate clusters, adaxial on whorl branchlets and pinnules. Sporangia ovate, ca. 45 x 35 µm, cruciately divided. Spermatangial heads paniculate, in general replacing first or second order pinnules on both major and minor branchlets. Female structures not seen. Description from Stegenga et al. (1997): based on west coast material, as Platythamnion recurvatum.

Collections, ecology and regional distribution

Recorded from Paternoster and a few other sites on the west coast, with the most easterly south coast site being Port Alfred (11-39). An infrequent species, only found in drift; epiphytic or epizoic.

World distribution: Apparently only otherwise known from California, USA.

Type locality: Moss Beach, Monterey Co., California, USA (Silva et al. 1996).

Note: 1. The genus Pterothamnion now includes the former genera Platythamnion and Glandothamnus (see Athanasiadis & Kraft 1994). The species of Platythamnion that we had recorded on our west coast (Stegenga et al. 1997) and south coast are therefore now placed in Pterothamnion.

Pterothamnion recurvatum. 1 Whorl branchlets with spermatangial heads. 2 Tetrasporangia. Reproduced from Stegenga et al. (1997) (as Platythamnion recurvatum).

Order Ceramiales

Family Ceramiaceae

Pterothamnion sp.

Plant (fragment) only 2 mm long, with a prominent main axis and two opposite rows of branchlets. Main axial cells up to 100 µm in diameter and about as long. Laterals much narrower, to 400 µm long, branched at the adaxial side for a number of segments. Apical cells of branchlets and ramuli with a sharp spike. Second order branchlets often with two ramuli on the basal segments, otherwise with one ramulus per segment, mainly adaxially. Gland cells present in various positions on second and third order ramuli, prominent, measuring up to 25 µm across. Material not fertile, hence we have not been able to identify this specimen.

Only found at Xora River, May 1999 (slide X001).

Note: Note: the genus Pterothamnion now includes the former genera Platythamnion and Glandothamnus (see Athanasiadis & Kraft 1994).

Pterothamnion species. Note opposite rows of branchlets.

Order Ceramiales

Family Ceramiaceae

Ptilothamnion Thuret

Thallus filamentous, endo/epiphytic, minute (to ca. 15 mm tall but often much smaller), comprising prostrate axes bearing erect, sparsely branched or pinnate axes. Cells multinucleate. Gametophytes monoecious or dioecious. Tetraporangia or polysporangia sessile or pedicellate, borne on emergent erect filaments. Worldwide, 13 species are currently recognized (Guiry & Guiry 2015), of which three are found on the south coast.

Note: Ptilothamion subsimplex Gordon-Mills: There is not enough evidence to record this species for Transkei as done by Bolton & Stegenga (1987).

Key to species

1a. Growing in the felty foot of Zonaria, emergent parts up to 1(-1,5) mm tall, consisting of cells little longer than broad

Ptilothamnion
codicolum

1b. Usually on other substrata, emergent parts larger, with longer cells

2

2a. Plants growing on Dichotomaria and Galaxaura, emergent filaments 25-35 µm thick; sporophytic plants with tetrasporangia, carposporophytes with enveloping filaments from hypogenous and subhypogenous cells

Ptilothamnion
goukammae

2b. Plants growing on a wide variety of algae (including Zonaria, Dichotomaria and Galaxaura), emergent filaments to 50-60 µm in diameter thick; sporophytic plants with polysporangia, carposporphytes with enveloping filaments from the hypogenous cell only

Ptilothamnion
polysporum

Order Ceramiales

Family Ceramiaceae

Ptilothamnion codicola (E.Y.Dawson) I.A. Abbott 1971: 355, no fig. (as 'codicolum' )

Plants semi-endophytic in the felty foot of Zonaria subarticulata, endophytic part frequently branching; emergent filaments up to 0.5 (-1) mm long, only branched at the foot, ca. 25 µm in diameter, the cells little longer than broad.

Polysporangia terminal on short filaments from the base of the emergent filaments, measuring ca. 62 µm in diameter, with 16 spores measuring ca. 25 µm across at maturity. Spermatangial heads terminal on short erect filaments that originate in the endophytic part or from the base of the erect filaments, with a three-celled axis, almost globular at maturity, ca. 50 x 45 µm. Female fertile filaments two-celled, terminal on short filaments from the bases of emergent filaments. The subapical cell of the fertile filaments bears two pericentral cells, one becoming the supporting cell and bearing a sterile cell and a 4-celled carpogonial filament. The trichogyne is long and thick (12 µm). Post-fertilization structures have not been observed in our material. If involucral filaments are present, then they develop only after fertilization.

Collections, ecology and regional distribution

In South Africa only known from the south coast, collected between Stilbaai and Morgan Bay (25-43).

World distribution: recorded elsewhere only from Pacific North-America and Portugal.

Type locality: Isla Guadalupe, Baja California, Mexico (Dawson 1962).

Note: There remains some doubt as to the identity of this species in comparison with material described from California (Abbott 1971).

Ptilothamnion codicola, habit, in rhizoidal part of Zonaria.subarticulata, Jongensfontein. Stained slide.

Ptilothamnion codicola, habit. Stained slide.

Order Ceramiales

Family Ceramiaceae

Ptilothamnion goukammae Stegenga, Bolton & R.J. Anderson 2002: 583, figs 2, 3

Plants caespitose, partly endophytic, emergent filaments numerous, up to 2.5 mm tall. Filaments throughout the plant 25-35 µm, not notably tapering toward the apices. Cell length varying a great deal, up to 300 µm in the endophytic part, down to 37.5 µm in apical parts bearing reproductive structures. Branching rather irregular, becoming more intensive in the apices as reproductive structures emerge.

Tetrasporangia mainly in adaxial rows on the proximal parts of the branches, measuring 50-62.5 x 40-50 µm, tetrahedrally divided. Spermatangial heads terminal on branches, ovoid to short cylindrical, with a 3(-4)-celled axis, measuring 75-87.5 x 52.5-62.5 µm. Female fertile filaments two-celled, the second cell with three pericentrals, two remaining sterile. The fertile pericentral cell with a four-celled carpogonial filament and a sterile cell. The mature carposporophyte with two or three gonimolobes, roundish, up to 180 µm in diameter, carpospores ca. 25 µm in diameter, in a gonimolobe showing simultaneous development. Prior to fertilization, single involucral filaments develop from hypogenous and subhypogenous cell and sometimes from the cell below as well.

Collections, ecology and reginal distribution

This species is known from Goukamma only (29). With its substratum species (Dichotomaria obtusata and Dichotomaria diessingiana) , it grows in deep intertidal pools with much influence of sand. It grows on subterminal sections of the substratum, while lower down another species of the genus, Ptilothamnion polysporum, may be found.

World distribution: South African endemic.

Type locality: Oesterbank (oyster beds) of the Goukamma Nature Reserve, Western Cape Province, South Africa (Stegenga et al. 2002).

Ptilothamnion goukammae, male stands, Goukamma oyster beds, growing on Dichotomaria diessingiana and Dichotomaria obtusata. Stained slide.

Ptilothamnion goukammae, female fertile filaments (unfertilized), Goukamma oyster beds, growing on Dichotomaria diessingiana and Dichotomaria obtusata. Stained slide.

Order Ceramiales

Family Ceramiaceae

Ptilothamnion polysporum Gordon-Mills & Wollaston in Wollaston 1984: 293, figs. 2-6, 9-11

Plants epilithic or epiphytic on a variety of other algae, not developing an endophytic system, but creeping filaments attached by unicellular haptera. Erect filaments up to 15 mm tall, but as a rule much shorter in epiphytic plants. Filaments in basal areas usually little branched, ca. 50-60 µm in cross section, cells about 3-5(-7) times as long, in the fertile tips thallus branched, the cells much shorter, the apical cells not much narrower.

Polysporangia in branched thallus apices on the adaxial sides of branches, mostly containing 8-12 spores, measuring 85-110 x 75-100 µm. Spermatangial stands sessile, more or less alternating on several subapical cells of erect axes, with a 3-celled axis, measuring ca. 100 x 60 µm at maturity. Female fertile filament two-celled, developed in apical position, but overtopped by two involucral filaments from the hypogenous cell that may develop new female stands, even if the first-formed carpogonium is successfully fertilised. Mature carposporophytes ca. 180 µm in diameter, containing relatively few spores of ca. 50 µm; they show successive development.

Collections, ecology and regional distribution

Found from Swartklip in False Bay along the whole south and east coasts (18-58) into Mozambique (Stegenga et al. 1997).

World distribution : Also in Northern Namibia, but probably absent on the South African west coast and southern Namibia. Australian material was included tentatively in this species as reproductive structures were absent (Wollaston 1984).

Type locality: St. Michaels-on-the-Sea, Natal, South Africa (Wollaston 1984).

Ptilothamnion polysporum. 1 Habit. 2 Polysporangia. Reproduced from Stegenga et al. (1997).

Ptilothamnion polysporum. Polysporangia, Goukamma oyster beds, stained slide.

Ptilothamnion polysporum. Male stands, Goukamma oyster beds, stained slide.

Ptilothamnion polysporum. Carposporophyte, Goukamma oyster beds east, stained slide.

Ptilothamnion polysporum. Female fertile filament, Goukamma oyster beds, stained slide.

Ptilothamnion polysporum. Repeated branching and formation of female fertile filaments, Goukamma oyster beds, stained slide.

Order Ceramiales

Family Ceramiaceae

Scageliopsis tsitsikammae Stegenga, R.J. Anderson & J.J. Bolton 2000: 485, figs 5-12

Plants without a rigid distinction between creeping and upright filaments. Creeping filaments ca. 20 µm in diameter, cells up to 50 µm long. Erect axes to 1 mm tall, 15(-20) µm in diameter basally, decreasing to 5 µm apically, cells (much) shorter than in the basal filaments, especially near the apices. Each segment with two or three branchlets, these up to 100 µm long, a few times forked. Indeterminate branches few, developing from determinate branchlets. Gland cells varying in number and position, abutted by a single vegetative cell.

Tetrasporangia not seen or at least only seen in an early (undivided) stage. Spermatangial clusters on a number of proximal cells of the branchlets, usually replacing a vegetative lateral. Carpogonial filament developing on the basal cell of ordinary branchlets. This cell cuts of an auxiliary cell, which after fertilization cuts off or functions immediately as a gonimoblast initial, producing a number of gonimolobes in succession. Gonimolobes up to 100 µm in diameter, carpospores produced simultaneously; ripe carpospores ca. 25 µm in cross section. Special involucral filaments lacking. (Description according to Stegenga et al. 2000).

Collections, ecology and regional distribution

Known only from the type locality, Tsitsikamma (32), where it grew on sponge at ca. 24 m depth.

World distribution: South African endemic.

Type locality: Middlebank, ca. 1.5 km offshore near Storms River Tsitsikamma Coastal National South Africa (Stegenga et al. 2000).

Note: see Stegenga et al. (2000) for further details and illustrations.

Scageliopsis tsitsikammae, vegetative thallus. Stained slide.

Scageliopsis tsitsikammae, vegetative thallus showing main axis. Stained slide.

Scageliopsis tsitsikammae, vegetative thallus showing gland cells (dark blue). Stained slide.

Order Ceramiales

Family Ceramiaceae

Syringocolax macroblepharis Reinsch 1875: 66, Rhodophyceae pl. IV, pl. LVII: fig. 2

Plants parasitic, forming whitish pustules a few mm in diameter on the main axes of the host (Gelidium spp.). centre of the pustule pseudo-parenchymatous, a more or less compact “stalk” penetrating the host tissue; pustule on the periphery covered with unbranched filaments up to 1.5 mm long bearing the reproductive structures. Filaments slightly curved at the apex, uniaxial, each cell of the central filament with a ring of periaxial cells; number of periaxial cells varying from 3 in the proximal parts to 7 (-8) in the more distal and fertile parts; some secondary cortication usually developing, almost exclusively in acropetal direction ; downward-growing rhizoids formed in the proximal part of the axes, contributing to the formation of the pseudo-parenchymatous core of the plant.

Tetrasporangia formed in whorls of up to seven per segment, cut off from the periaxial cells, immersed in the cortex, but exposed in the periphery; sporangia measuring up to 30 x 25 µm, tetrahedrally divided. Sexual plants dioecious. Spermatangia formed on the surface of most of the male axes. Carpogonial filaments in a secund series on the convex side of apical sections of the axes, periaxial cells functioning as supporting cells; usually a row of sterile hairs running parallel to the row of carpogonial filaments. Only one carposporophyte maturing per erect axis, consisting of 2-4 globose stalked gonimolobes, surrounded by up to 8 involucral filaments originating from one or two segments below the fertile segment.

Collections, ecology and regional distribution

We have not found this species in the area, but Martin & Pocock (1953) record it between Cape Agulhas and Morgan Bay (22-43), as a parasite on Gelidium spp.

World distribution: South African endemic.

Type locality: Cape Agulhas, Cape Province, South Africa (Martin & Pocock 1953).

Syringocolax macroblepharis. 1 Habit of female plant (on Gelidium sp. sectioned). 2 Apex of tetrasporiferous axis. 3 Male axis with spermatangia, juvenile. 4 Cortication pattern: older axis, proximal part. 5 Top of female fertile axis. 6 Carposporophyte. Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Ceramiaceae

Zonariophila semiendophytica Stegenga et Kemperman 1996

Plants semi-endophytic in Zonaria subarticulata, the (single) endophytic cell large, up to ca. 1 mm long, 250 µm high and at maximum100 µm broad. Endophytic cell running perfectly parallel to the cell rows of Zonaria, piercing the substratum on both sides and producing numerous (up to 25) short erect filaments, from dorsal as well as ventral side. Emergent filaments rarely more than 6 (-10) cells long, moderately incurved, branched a few times from the lower segments. Emergent filaments to ca. 1.5 mm long, the diameter varying from 60 µm basally to 130 µm (sub)apically; cell length to 300 µm.

Tetrasporangia in repeatedly branched clusters on the lower cells of the erect branches, measuring up to 85 x 70 µm. Spermatangial clusters more or less cylindrical, with a 4-5-celled axis, one cluster per cell of the erect axes. Male stichidia ca. 175 x 100 µm.

Female fertile filament two-celled, the second cell with one fertile and two sterile cells. Carposporophyte to ca. 500 µm in diameter, with up to four involucral filaments from the hypogenous cell. All cells of a gonimoblast maturing at the same time, measuring about 60 µm in diameter at the time of release.

Collections, ecology and regional distribution

Collected between Cannon Rocks and Kei Mouth (39-43). Not found very frequently, but where it occurs the host may be heavily infested.

World distribution: South African endemic.

Type locality: Shark Bay, Port Alfred (Stegenga & Kemperman 1996).

Zonariophila semiendophytica. Young plants in Zonaria subarticulata, Cannon Rocks (stained slide).

Zonariophila semiendophytica. Microscopic habit (stained slide).

Order Ceramiales

Family Dasyaceae

Dasya C. Agardh

Thallus erect, bottlebrush-like or bushy. Development sympodial, with irregular, opposite or alternate branching. Indeterminate axes producing determinate monosiphonous pseudolaterals from each polysiphonous segment. Spermatangia similarly borne in heads on pseudolaterals. Carposporophytes, where known, enclosed in a sterile pericarp. This genus on the south coast needs taxonomic attention: we appear to have at least three undescribed species.

Key to species

1a. Branching angle in distal dichotomies about 90o; ultimate ramuli relatively short, straight

D. echinata

1b. Branching angle in distal dichotomies narrow or at least less than 60o; ultimate ramuli relatively long

2

2a. Thallus with extensive, fully corticated creeping axes; main erect axes incompletely corticated

Dasya sp III

2b. Thallus mainly erect with no or short creeping axes; main erect axes fully corticated

3

3a. Main axes prominent and thickly corticated, up to 1 mm in diameter, thickly clothed with pseudolaterals

Dasya scoparia

3b. Main axes corticated but less than 250 µm in diameter

4

4a. Thallus with short creeping system bearing more than one erect axis; pseudolaterals branched up to 5 times; tetrasporangial stichidia ca 800 µm X 125 µm

Dasya sp II

4b. Thallus erect with no creeping system; pseudolaterals branched 2-3 times; tetrasporangial stichidia ca 350 µm X 100 µm

Dasya sp I

Order Ceramiales

Family Dasyaceae

Dasya echinata Stegenga, Bolton & Anderson 1997: 498

Plants erect, with irregularly branched main axis, up to 10 cm tall. Axes clothed with fairly stiff pseudolaterals, forming bottlebrush-like apices on the plant, older parts of the axes denuded. Main axis with 5 pericentral cells and thick cortication; rhizoidal filaments penetrating between central and pericentral cells; older axes up to 1 mm in diameter. Pseudolaterals monosiphonous, dichotomously branched every second or third segment, angle of dichotomies about 90o. Ultimate ramuli 4-8 cells long, straight, almost spine-like. Pseudolaterals proximally ca. 90 µm in diameter, tapering to acute, the cells about as long as broad. Tetrasporangial stichidia conical to cylindrical, forming one arm of a dichotomy of a pseudolateral. Stichidia ca. 600 x 150 µm, the segments with five or six pericentral cells and tetrasporangia. Sporangia globose, ca. 45 µm in diameter, tetrahedrally divided. Tetrasporiferous pericentral cells with three cover cells in a horizontal row. Sexual reproductive structures unknown.

Collections, ecology and regional distribution

Recorded from Strandfontein, False Bay to Waterloo Bay (18-40). Found in the sublittoral fringe.

World distribution: South African endemic.

Type locality: Brandfontein, just west of Cape Agulhas (Stegenga et al. 1997).

Dasya echinata, type specimen (BOL), collected just west of Cape Agulhas.

Dasya echinata, detail of type specimen (BOL). Stained slide material.

Dasya echinata, tetrasporangial stichidia.

Dasya echinata. 1. Habit. 2. Pseudolateral. 3. Cross section of main axis. 4. Tetrasporangial stichidium. Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Dasyaceae

Dasya scoparia Harvey ex J. Agardh 1841: 34-35

Plants erect, up to ca. 10 cm tall. Axes irregularly branched, thickly clothed with pseudolaterals, giving rather shaggy appearance. Principal axis with 5 pericentral cells and thick cortex, up to 1 mm in diameter. Pseudolaterals monosiphonous, arising one per segment in spiral pattern, in proximal parts three or four times dichotomously branched, ca. 70 µm in diameter, tapering distally; ultimate ramuli up to ca. 15 cells long, incurved, the cells 2-3 times longer than broad. Tetrasporangial stichidia conical to cylindrical, forming one arm of an ultimate or penultimate dichotomy of a pseudolateral. Stichidia up to 600 µm long, 150 µm in diameter; segments with four pericentral cells and tetrasporangia. Sporangia globose, ca. 40 µm in diameter, tetrahedrally divided. Tetrasporiferous pericentral cells with three cover cells in a horizontal row. Sexual structures not found.

Collections, ecology and regional distribution

Recorded from Lamberts Bay on the west coast to northern Kwazulu-Natal (9-58). Found in rock pools and from the sublittoral fringe to shallow sublittoral.

World distribution: Africa: Namibia, Mozambique, Kenya and Mauritius, Reunion Island. Asia: China and Japan. (Guiry & Guiry 2010).

Type locality: Cape of Good Hope, South Africa (Agardh 1841).

Dasya scoparia, Arniston.

Dasya scoparia, Goukamma, pressed specimen (BOL).

Dasya scoparia, fresh material (Arniston) under dissecting microscope.

Dasya scoparia. 1. Habit. 2. Pseudolateral with tetrasporangial stichidia. 3. Tetrasporangial stichidium in detail. Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Dasyaceae

Dasya sp 1

Main axes corticated, in distal regions densely covered by pseudolaterals; pseudolaterals monosiphonous, arising from each segment in spiral pattern, cells 35-60 µm wide at base, about 35 µm wide in mid-regions and 3-4 times longer than broad, branched 2-3 times, terminal unbranched portions up to 9 cells long. Tetrasporangial stichidia attenuated cone-shaped, about 350 µm long and 100 µm wide; tetrasporangia about 30 µm in diameter, with three cover cells in a horizontal row.

Collections, ecology and regional distribution

Collected from Keurboomstrand to Hluleka, Transkei (31-45).

Note: this entity is rather similar to, but has pseudolaterals with smaller cell dimensions than, D. scoparia. There are also specimens that are similar to this entity but have rather sparse pseudolaterals (but one per segment): it is clear that Dasya species on the south coast are in need of further study.

Dasya sp I (EC 288, Keurboomstrand), stained slide.

Dasya sp I (EC 477, Kenton on Sea), stained slide.

Dasya sp I detail (EC 477, Kenton on Sea), stained slide.

Order Ceramiales

Family Dasyaceae

Dasya sp 2

Plants erect, but possessing more than one erect axis from a short creeping system; up to 1.5 cm tall. Very few indeterminate laterals present. Principal axes with 5 pericentral cells, from an early stage covered by a cortex; main axes to 200 µm in diameter, the segments to 250 µm long. Pseudolaterals monosiphonous, up to ca. 2 mm long, arising one per segment in a spiral pattern; no adventitious laterals present. Pseudolaterals branched up to 5 times, with intervals of usually 2 cells (sometimes 3 or 4 cells in the higher dichotomies), diameter from 75 µm basally to 15-22 µm apically. Ultimate ramuli to 17 cells long, nearly straight, the cells cylindrical and up to 4 times longer than broad. Tetrasporangial stichidia usually one per pseudolateral, on the 2nd to 4th ramification, cylindrical with attenuated top, up to 800 X 125 µm. 5 sporangia per verticel, at maturity to 50 µm in diameter, each with 3 short cover cells. Sexual reproductive structures not seen.

Collections, ecology and regional distribution

Only found in the Kowie estuary (39), and therefore apparently able to survive temporarily reduced salinity of the water. Attached to floating buoys on jetty.

World distribution: unknown.

Dasya sp II with tetrasporangial stichidia (stained slide).

Dasya sp II sparse indeterminate laterals and tetrasporangial stichidia (stained slide).

Dasya sp II detail of tetrasporangial stichidia (stained slide).

Order Ceramiales

Family Dasyaceae

Dasya sp 3

Plants with relatively large repent parts, attached by many multicellular rhizoids originating from the outer cortical cells of the main axes. Several erect axes arising from the prostrate part, up to ca. 1.5 cm tall. Apical sections of erect axes for some distance uncorticated, with 5 pericentral cells, cortication becoming complete only in the repent axes. Repent axes to 500 µm in diameter, erect axes rarely more than 250µm in diameter. Each segment with a single pseudolateral; pseudolaterals monosiphonous, up to 2 (-2,5) mm long, branched once from the second or third (fourth) cell, occasionally forming a second lateral two cells higher up; unbranched end of ramuli up to 20 cells long. Pseudolaterals up to ca. 50 µm in diameter at the base, only little incurved, the cells up to 200 µm long; young branchlets tapering to a triangular apical cell, in older branchlets the apical cell becoming rounded, often shorter than broad. Tetrasporangial stichidia up to 700 X 150 µm, often formed instead of the first branch of a pseudolateral, sometimes a second stichidium two cells higher up. When bearing stichidia the proximal cells of the pseudolateral remaining shorter than broad. Fertile segments with 6 tetrasporangia up to 50 µm in diameter, each with 3 comparatively long cover cells. Sexual reproduction not seen.

Collections, ecology and regional distribution

Found in the lower intertidal and sublittoral fringe at Preekstoel, Stilbaai (28) and Mkambati (47), implying a distribution along coastal sections 28-47.

World distribution: unknown.

Dasya sp III, partly corticated main axis and monosiphonous pseudolaterals (stained slide).

Dasya sp III, partly corticated main axis and monosiphonous pseudolaterals (stained slide).

Dasya sp III, corticated repent axis with attaching rhizoids and erect axes (stained slide).

Dasya sp III, apical portion of thallus (stained slide).

Dasya sp III, tetrasporangial stichidia (stained slide).

Dasya sp III, detail of tetrasporangial stichidium (stained slide).

Order Ceramiales

Family Dasyaceae

Dipterocladia pinnatifolia (Suhr) Y.S.M. De Jong 1997

Thallus pinkish-red, complanate, to about 10 cm tall, axes up to four times alternately pinnately branched; main axes up to 5 mm wide, compressed, tapering towards apices, which bear monosiphonous pseudolaterals except older branches where these have been shed; main axes basally corticated, rather rigid, becoming delicate near apices, structure of central cell surrounded by 4 periaxial cells (5th periaxial cell absent or reduced), layer of subcortical cells and cortex of rhizoidal filaments; each axial segment bearing two laterals (one uncorticated monosiphonous pseudolateral and one determinate sympodial lateral) arranged in alternating distichous pairs. Tetrasporangia in stichidia that replace determinate sympodial laterals, borne on short polysiphonous corticated pedicels, lanceolate to sickle-shaped, about 400 (-700) µm long, with 6 periaxial cells and 6 tetrasporangia per segment, each eventually partially covered by 6 sterile cover cells. Gametophytes unknown.

Collections, ecology and regional distribution

Known from Algoa Bay to Scottburgh in southern Kwazulu-Natal (36-50). Apparently rather rare, collected mainly in drift but also known from Southern Kwazulu-Natal reefs down to 35 m depth.

World distribution: South African endemic

Note: this species was known earlier as Eupogodon pinnatifolius (Suhr) Silva, then stated by Millar (1996) to be synonymous with Mediterranean Eupogodon planus, (C.Agardh) Kützing, but described as a new genus by De Jong et al. (1997).

Dipterocladia pinnatifolia, herbarium specimen from Woody Cape (BOL 16395).

Dipterocladia pinnatifolia, tetrasporangial stichidia (stained slide).

Dipterocladia pinnatifolia, single tetrasporangial stichidium (stained slide).

Dipterocladia pinnatifolia, cross section of thallus (stained slide).

Order Ceramiales

Family Dasyaceae

Heterosiphonia Montagne

Thallus erect or partly prostrate, feather-like or bushy, dorsiventrally organised; branching sympodial, distichous pseudolaterals arising at intervals of every two or more segments, branching irregular, subdichotomous or alternate. Axial cell surrounded by 4-12 periaxials; mature axes with or without rhizoidal cortication. Plants dioecious, carposporophytes with prominent corticated pericarps, ostiolate; spermatangia in whorls in linear to lanceolate stichidia.

In addition to the three species below (descriptions from Stegenga et al. 1997), we recorded an entity similar to H. arenaria but with a thicker main axis and some cortication (see illustrations under H. arenaria), which may represent an undescribed species.

Key to species

1a. Segments of main axes with 4 pericentral cells

H. crispa

1b. Segments of main axes with more than 4 pericentral cells

2

2a. Pseudolaterals arising at intervals of every second segment

H. dubia

2b. Pseudolaterals arising at intervals of every third to fourth segment

H. arenaria

Order Ceramiales

Family Dasyaceae

Heterosiphonia arenaria Kylin 1938: 17, pl. 6: fig. 17

Plants partly prostrate, entangled with other algae; attached by rhizoids developing on modified pseudolaterals. Erect parts up to 5 cm tall, pinnate; segments of main axis uncorticated, with 8-10 pericentral cells surrounding central cell. Pseudolaterals alternate, arising at intervals of 3-4 segments, several times distichously branched at intervals of 2 or 3 segments; proximal segments of pseudoaterals polysiphonous, ultimate ramifications monosiphonous, apical ramuli ca. 10-15 cells long, more or less incurved. Tetrasporangial stichidia borne on polysiphonous part of the pseudolaterals; stichidia conical, up to 800 x 250 µm; segments with (in general) six pericentral cells and tetrasporangia; sporangia globose, ca. 70 µm in diameter, tetrahedrally divided, pericentral cells with two groups of two cover cells. Sexual reproductive structures not seen.

Collections, ecology and regional distribution

Recorded from Swartklip in False Bay to Cape Vidal area in KwaZulu-Natal (18-56). Found in algal turfs in the sublittoral fringe.

World distribution: South African endemic.

Type locality: Humewood Beach, Port Elizabeth (Silva et al. 1996).

Note: Stegenga et al. (1997) record the occurrence (De Hoop and the Eastern Cape) of a similar entity with “a thicker main axis with some development of cortication”. A De Hoop specimen is illustrated here (as Heterosiphonia sp. De Hoop D163).

Heterosiphonia arenaria, dissecting microscope photograph, scale bar ca. 500 µm.

Heterosiphonia arenaria, branch detail.

Heterosiphonia arenaria, tetrasporangial stichidium (stained slide).

Heterosiphonia arenaria. 1. Detail of main axis and pseudolaterals. 2. Immature tetrasporangial stichidium. 3. Pseudolaterals with tetrasporangial stichidia. Reproduced from Stegenga et al. (1997).

Heterosiphonia sp De Hoop (D 163), dissecting microscope photograph.

Heterosiphonia sp (De Hoop specimen D 163).

Heterosiphonia sp branch detail (De Hoop specimen D 163).

Heterosiphonia sp, transverse section of distal axis, showing axial cell and pericentral cells (De Hoop specimen).

Order Ceramiales

Family Dasyaceae

Heterosiphonia crispa (Suhr) Falkenberg 1901: 642-643

Plants largely prostrate, often entwined among other algae in turfs. Main prostrate axes attached by branched multicellular haptera developing from modified pseudolaterals. Main axis up to 200 µm in diameter; pseudolaterals alternate, distichous, arising from every second segment. Segments with four pericentral cells, cortication absent. Pseudolaterals, with exception of the basal segment, monisiphonous, subdichotomously branched every second segment; terminal ramuli 5-10 cells long with acute apices. Tetrasporangial stichidia borne on pseudolaterals, replacing one of the branches of an ultimate pseudodichotomy. Stichidia conical to cylindrical, up to 750 µm long and 150 µm in diameter; segments usually with four pericentral cells and tetrasporangia. Sporangia globose, ca. 50 µm in diameter, tetrahedrally divided, pericentral cells with two groups of two cover cells. Cystocarps up to 1 mm long, urn-shaped, with rather long neck and wide ostiole.

Collections, ecology and regional distribution

Recorded from Lamberts Bay on the west coast to Sodwana Bay in Kwazulu-Natal (9-57). Common in turfs of mixed algae and mussel beds in the lower eulittoral.

World distribution: Also recorded from Namibia (Rull Lluch 2002) and from Mozambique (as H. capensis Falkenberg: Silva et al. 1996).

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

Note: We follow Stegenga et al. (1997) in including H. capensis Falkenberg in H. crispa.

Heterosiphonia crispa, fresh specimen, Nature’s Valley.

Heterosiphonia crispa, tetrasporangial stichidium, stained slide.

Heterosiphonia crispa. 1. Detail of main axis with pseudolaterals. 2. Prostrate axis, showing attachment structure. 3-4. Tetrasporangial stichidia. 5. Cystocarp. Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Dasyaceae

Heterosiphonia dubia (Suhr) Falkenberg 1901: 639-642

Plants up to several cm long, often partly or largely prostrate, axes attached by modified proximal ramuli of the pseudolaterals. Main axis up to 200 µm in diameter; pseudolaterals alternate, distichous, arising from every second segment. Segments of main axis with 7 or 8 pericentral cells, cortication absent. Pseudolaterals several times subdichotomously branched every other segment; only ultimate 2-3 ramifications monosiphonous, 2-4 cells long with blunt apices; other segments polysiphonous but often with reduced number of pericentral cells (usually 6). Tetrasporangial stichidia developing as one arm of an ultimate or penultimate dichotomy of a pseudolateral. Stichidia conical to cylindrical, up to 1300 µm long and 200 µm in diameter, segments with 5 pericentral cells and tetrasporangia. Sporangia globose, ca. 50 µm in diameter, tetrahedrally divided, pericentral cell with two groups of two cover cells. Cystocarps urn-shaped, ca 1 mm long.

Collections, ecology and regional distribution

Recorded from Paternoster on the west coast to the Scottburgh area of the Kwazulu-Natal coast (11-50). Fairly common in the lower eullitoral zone, usually as a component of mixed algal turfs.

World distribution: also recorded from Namibia (Rull Lluch 2002).

Type locality: Either False Bay (Western Cape Province) or Algoa Bay (see note in Silva et al. 1996).

Heterosiphonia dubia with tetrasporangial stichidia, dissecting microscope photograph of fresh specimen, Port St Johns. Scale bar 1 mm.

Heterosiphonia dubia with tetrasporangial stichidia, stained slide.

Heterosiphonia dubia, showing pseudolateral with developing attachment structure (stained slide).

Heterosiphonia dubia. 1. Thallus apex. 2. Pseudolateral with developing attachment structure. 3. Tetrasporangial stichidium. 4. Cystocarp. Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Delesseriaceae

Acrosorium Zanardini ex Kützing

Plants of various shapes, mainly monostromatic but polystromatic on older (basal) parts and sometimes along (microscopic) veins; microscopic veins comprising elongated cells; branching where present from margins of blades. Growth from cells in thallus margin.

Tetrasporangia and spermatangia in sori below the edges of blades; cystocarps scattered in blades.

Key to Acrosorium species

Key to species

1 a. Blades narrow, strap-like (to 3 mm wide), some apices forming hooks or sickle-like hamifera

A. ciliolatum

1 b. Blades wider, without terminal hooks or hamifera

2

2 a. Blades with scattered, pale to yellowish spots

A. maculatum

2 b. Blades without pale spots

A. acrospermum

Notes:

1. Two Acrosorium species recorded from this coast are not described here:

 Acrosorium deformatum (Suhr) Papenfuss 1943: 90-91

This small (to 5mm high) species is recorded from the Eastern Cape (type locality Algoa Bay) as an epiphyte on an unidentified Gelidium species, and was earlier included as a possible synonym of A. acrospermum by J. Agardh (see Papenfuss 1943: 90). We have neither collected nor seen specimens of this entity, but have seen several specimens of small A. acrospermum, A. maculatum and A. ciliolatum that grow as epiphytes on various larger algae, often partly wound around and adherent on the thallus.

Acrosorium amphiroae Jaasund 1976: 119 fig 241 (nom. inval.)

Two specimens are ascribed to this species from Hluleka in Transkei (Bolton and Stegenga 1987). The specimens are epiphytic on Amphiroa bowerbankii and Amphiroa ephedraea, growing as a thin tube that surrounds the thallus of the coralline alga, but with upright portions. However, the presence of pale spots in some of these indicates that they may be Acrosorium maculatum.

2. Examination of many BOL specimens suggests that all these species need to be re-examined. For example, there are some that are small, linear, have hooked tips but have pale spots (A. ciliolatum or A. maculatum?). Also, Stegenga et al. (1997) point out that A. maculatum and A. acrospermum seem to differ only in the former having pale spots.

Order Ceramiales

Family Delesseriaceae

Acrosorium acrospermum (J. Agardh) Kylin 1924: 78

Plants bright red, up to 5 cm tall, fan-shaped, rather delicate. Blades variously incised, lobed, rather contorted, monostromatic except at the base and in veins. Tetrasporangia in patches of sori near the edges of blades; cystocarps scattered on blades, distinctly swollen, with single prominent ostiole.

Collections, ecology and regional distribution

Found from the southern Cape Peninsula to Cape Vidal area in northern Kwazulu-Natal (17-56). Epilithic or often epiphytic in rock pools, lower eulittoral and shallow sublittoral zones.

World distribution: Also recorded from Namibia (Rull Lluch 2002) and St Paul Island (Silva et al. 1996).

Type locality: “In mari Capense” (South Africa) (Silva et al. 1996).

Notes:

Papenfuss (1939) described the reproductive morphology of this species in detail.

Stegenga et al. (1997) point out that this species is strikingly similar to A. maculatum except for the occurrence of pale spots in blades of the latter.

South coast specimens are in general smaller than some of the large specimens collected from the west coast.

Acrosorium acrospermum, well-developed thalli on sandy worm tube. Cystocarps arrowed.

Acrosorium acrospermum, detail of cells and vein (surface view).

Acrosorium acrospermum, habit, tetrasporangial. Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Delesseriaceae

Acrosorium ciliolatum (Harvey) Kylin 1924: 78

Plants creeping, red, delicate, up to 5 cm long. Blades ribbon-like, up to 3 mm wide, usually pointed at tips, attached by rhizoids (often near margins). Branching from margins (irregular to pinnate), branches sometimes ending in hooked or sickle-shaped tips (hamifera). Thallus monostromatic except at microscopic veins and inner curves of hooked apices, where there may be up to 3 cell layers. In surface view cells polygonal, 40-60 µm diameter in central parts of thallus. Tetrasporangial sori circular, sub-marginal; sexual structures not seen.

Collections, ecology and regional distribution

Found from the southern Cape Peninsula to northern Kwazulu-Natal (16-49). Common from the sublittoral fringe to at least 35 m depth. Often epiphytic or entangled with other algae.

World distribution: widespread in temperate and tropical seas.

Type locality: King George Sound, Western Australia (Womersley 2003).

Note: A. ciliolatum includes two species previously recognized from South Africa: A. uncinatum and A. venulosum (see Womersley 2003). Essentially, this species includes all of those with hooked apices (De Clerck et al. 2005).

Acrosorium ciliolatum, showing hooked tips.

Acrosorium ciliolatum, habit, lower plant tetrasporangial. Reproduced from Stegenga et al. (1997)( as A. venulosum).

Order Ceramiales

Family Delesseriaceae

Acrosorium maculatum (Sonder ex Kützing) Papenfuss 1940a: 224

Plants bright red, up to 5 cm tall, with scattered pale/yellow patches and sometimes areas of iridescence. Fronds very variable in size (from 10-15 mm tall and 2 mm wide to 5 cm tall and 10 mm wide) , narrowly wedge-shaped, linear, irregularly lobed or incised; numerous microscopic veins present; blades monostromatic except for microscopic veins. Tetrasporangia in sori, one per apical thallus lobe; cystocarps scattered in blades, projecting from both sides but with single ostiole.

Collections, ecology and regional distribution

Recorded from Cape Peninsula to northern Kwazulu-Natal (17-58). Epilithic or commonly epiphytic; frequent in rock pools, lower eulittoral and sublittoral (to at least 12 m).

World distribution: Angola, Namibia, South Africa, Mozambique and also recorded from Sri Lanka (Silva et al. 1996).

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

Note: This species differs little from A. acrospermum. Specimens of A. maculatum from the south coast appear to be slightly smaller than the largest specimens from the west coast, which may grow to 10 cm.

Acrosorium maculatum growing on axes of Phloiocaulon suhrii, De Hoop.

Acrosorium maculatum with pale yellowish spots and tetrasporic sori.

Acrosorium maculatum highly magnified view of thallus surface showing veins and yellow areas.

Acrosorium maculatum. 1. Habit, tetrasporangial. 2. Apical region. 3. Surface view of cell arrangement. 4. Cystocarp in cross section. 5. Tetrasporangial sorus in crosss section. Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Delesseriaceae

Genus Apoglossum

Thalli small, delicate, comprising stipitate blades with branching from the midrib; tetrasporangia in sori on blades. Growth from single apical cell, blades of one cell layer except at midrib. Seven species are currently recognized worldwide (Guiry & Guiry 2013), of which two are found on the south coast. See Wynne (1984) for a discussion of South African Apoglossum species.

Key to species

1a. Thalli up to 25 mm tall, blades to 5 mm wide, tetraporangial sori linear,
parallel and adjacent to midrib

Apoglossum ruscifolium

1b. Thalli up to ca 12 mm tall, blades to 1.8 mm wide, tetrasporangial sori
circular, distal on blades

Apoglossum spathulatum

Order Ceramiales

Family Delesseriaceae

Apoglossum ruscifolium (Turner) J. Agardh 1898: 194

Plants bright red, to 4 cm tall, comprising several membranous, ovate-lanceolate blades with short stipes arising from a discoid holdfast. Blades up to 3 cm long and 5 mm wide with slightly wavy margins, rounded to slightly depressed apices, prominent midrib and numerous microscopic lateral veins; branching from midrib. Growth from single apical cell; primary cell row and four pericentral cells without intercalary cell divisions; subsequent orders of cell rows arising from lateral pericentral cells; not all tertiary cell rows reaching thallus margin. In cross-section, blades mostly monostromatic, midrib polystromatic; midrib shows single layer of large primary cells with small cortical cells restricted to dorsal and ventral surfaces. Tetrasporangia in linear sori on each side of midrib. Cystocarps on midrib, globose. Spermatangial sori in series of narrow strips running from midrib towards both blade margins.

Collections, ecology and regional distribution

Recorded from the west coast of the southern Cape Peninsula to the Port Shepstone area in southern Kwazulu-Natal (16-49). Found in the sublittoral fringe and below.

World Distribution: Widespread in the eastern North Atlantic and in the Mediterranean; also recorded from North Carolina to the Caribbean, Atlantic North Africa, St Paul Island in the Indian Ocean (Guiry & Guiry 2013, Silva et al. 1996).

Type locality: Norfolk, England (Guiry & Guiry 2013).

Note. See Wynne (1984) for a discussion of this species and A. spathulatum.

Apoglossum ruscifolium (length ca 30 mm).

Apoglossum ruscifolium. 1. Habit. 2. Thallus apex. 3. Cell arrangement at edge of mature blade. 4 Anatomy of midrib and adjacent area, in upper half superficial cell layers left out (central pericentral cells and lateral pericentral cells dotted). 5. Blade with spermatangial sori. Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Delesseriaceae

Apoglossum spathulatum (Sonder) Womersley and Shepley 1982: 329

Plants red, small (to 12 mm tall). Blades membranous, 5-11 mm long and 1.1-1.8 mm wide, linear-spatulate, substipitate, apices rounded to slightly obtuse, margins entire, microscopic veins present; branching from midrib, usually alternately from either side of the blade, rarely from margin; blades capable of secondary (rhizoidal) attachment to substratum. Growth from single apical cell; blade monostromatic except in midrib. Tetrasporangial sori discrete, circular to oval, near distal ends of blades, mature tetrasporangia 24-28 µm in diameter; cystocarps formed on most orders of branches, singly or in a pair on the midrib of each branch. Male thalli not observed.

Collections, ecology and regional distribution

Found from Wilderness to just north of Durban (29-51).

World distribution: fairly widespread in tropical and warm temperate water (Guiry & Guiry 2013).

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

Note: Wynne (1984) describes this species in detail.

Apoglossum spathulatum, re-drawn from Wynne (1984). A- cystocarpic plant, B – tetrasporic plant.

Order Ceramiales

Family Delesseriaceae

Bartoniella crenata Kylin 1924: 11

Plants erect, bright red, complanate, up to 8 (-12) cm tall. Fronds ribbon-like, 1.5-3 (-4) mm wide, with unevenly serrated edges, irregularly constricted, with distinct midrib in proximal regions, but no lateral veins, branched from edges and midrib (especially when fertile). Growth from prominent apical cell, producing axial filaments with 4 pericentral cells; lateral pericentrals giving rise to secondary and tertiary cell rows that reach thallus margin; central cell row and lateral pericentrals without intercalary divisions; thallus corticated towards base; central cell row and pericentrals clearly visible in cross-sections, surrounded by small cells in polystromatic parts of thallus. Reproductive structures on small leaflets arising from midrib or blade margins; tetrasporangia and spermatangia in paired oval sori on either side of midrib; cystocarps hemispherical, on midrib.

Collections, ecology and regional distribution

Found from Muizenberg (Stegenga et al. 1997) along south coast to Mission Rocks in northern KwaZulu-Natal (De Clerck et al. 2005) (17-57). Subtidal, attached to rock down to at least 35 m.

World distribution: although considered to be a South African endemic, this species was recorded once from Kenya (De Clerck et al. 2005).

Type locality: Kowie (Port Alfred) (De Clerck et al. 2005).

Note: this species is described in detail by Wagner (1954).

Bartoniella crenata, Kenton-on –Sea.

Bartoniella crenata, branches arising from margins and midrib.

Bartoniella crenata, tetrasporic marginal branch.

Bartoniella crenata, frond apex.

Bartoniella crenata, cross section through midrib area of blade.

Bartoniella crenata. 1. Detail of thallus with tetrasporiferous proliferations. 2. Thallus apex. 3. Cross section of blade (cc – central cell). Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Delesseriaceae

Caloglossa leprieurii (Montagne) G. Martens 1869: 234, 237

Plants forming violet to blackish tufts of ribbon-like fronds a few cm long. Fronds narrowly lanceolate, regularly constricted, branches and tufts of attaching rhizoids arising at constrictions; individual frond-sections between constrictions up to 3.5 mm long and 1100 µm wide. Small branches may occasionally arise from surfaces of the midrib. Growth from a prominent dome-shaped apical cell; transverse division produces a primary cell row, each cell of which produces two transverse and two lateral pericentral cells; lateral pericentrals give rise to secondary cell rows up to 20 cells long; tertiary cell rows develop on the abaxial side of proximal cells of the secondary cell rows and reach to thallus margin. Blades monostromatic except at midrib where they are normally 3 cells thick. Rows of tetrasporangia develop on the adaxial side of secondary cell rows, tetrasporangial areas extend from adjacent to midrib to submargins (at maturity at least 4 rows of cells remaining sterile); tetrasporangia roundish, to 50 µm in diameter, tetrahedrally divided. Spermatangia formed in sori on wings of thallus. Cystocarps globose, formed on midrib, up to 600 µm in diameter, at maturity with a short neck; carpospores ripening simultaneously, at maturity about 40 µm in diameter.

Collections, ecology and regional distribution

Recorded from as far west as the Berg River estuary on the SA west coast, and from a number of estuaries along the south and Kwazulu-Natal coasts (11-58). Restricted to estuarine environments, salt marshes and mangroves, often growing together with Bostrychia species

World distribution: worldwide in temperate to tropical localities (Guiry & Guiry 2013).

Type locality: French Guiana (Lipkin & Silva 2002).

Note 1: The development and reproduction of C. leprieurii  is described in detail by Papenfuss (1961).

Note 2: Caloglossa ogasawaraensis Okamura was reported from Hluleka, Transkei (Bolton and Stegenga (1987), and we have found one plant that resembles this species at Goukou Estuary, Stilbaai (see second figure). This species is smaller and narrower than C. leprieurii and has frond lobes about 300 um wide and up to about 3 mm long. However, the dimensions of some of our C. lepriuerii specimens overlap with the above, and in the absence of comprehensive collections we are uncertain as to whether C. ogasawaraensis occurs here.

Caloglossa leprieurii ( length ca 8 mm).

A narrow Caloglossa that closely resembles C. ogasawarensis (Goukou estuary, Stilbaai).

Caloglossa leprieurii. 1. Habit. 2. Thallus apex. 3. Wing of single segment in mature thallus (note secondary pit connection). 4. Tetrasporangia. Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Delesseriaceae

Gonimophyllum africanum Martin and Pocock 1953: 54-55, figs 2d,e

Plants parasitic on species of Delesseriaceae, forming pale pustules a few mm in diameter with cluster of minute blades emerging from the host frond. Endophytic part comprises monosiphonous filaments interspersed among host cells, cells of parasite and host becoming almost indistinguishable. Emergent part of thallus comprising a central pustule up to a few mm in size, bearing several minute blades on the periphery. Blades up to 2 mm long, with short stipes, cuneate or semicircular, with lobed margins. Blades succulent in appearance and almost completely polystromatic; single layer of medullary cells of up to 150 µm diameter, cortex of smaller cells; veins absent. Tetrasporangia scattered in cortex over both surfaces of blades, tetrahedrally divided, 40-50 µm long. Gametophytes dioecious. Spermatangia cut off from outer cortical cells over most of blade. Cystocarps one to several per blade, to 700 µm in diameter, hemispherical and projecting from surface, apparently without ostiole.

Collections, ecology and regional distribution

Recorded from Table Bay to the Kei River (Martin & Pocock 1953) (15-43). Parasitic on several species of Delesseriaceae, especially Acrosorium.

World distribution: Also reported from Uruguay (Coll & Oliveira 1999).

Type locality: Cove Rock, East London, South Africa (Silva et al. 1996).

Gonimophyllum africanum. Habit (white) on Botryoglossum platycarpum (a west coast species). Reproduced from Stegenga et al. (1997).

Gonimophyllum africanum. Section of margin of thallus (cells of substratum dotted). Reproduced from Stegenga et al. (1997).

Gonimophyllum africanum. 1. Male bladelet in longitudinal section. 2. Tetrasporangia. Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Delesseriaceae

Holmesia capensis J Agardh 1890: 39, pl. I: fig 4.

Plants dark red, fairly robust, comprising a few strap-shaped to lanceolate blades up to 30 cm long arising from a common, rather rhizomatous holdfast; some plants with flattened stipe-like, and occasionally branched basal axes, these apparently formed from persistent midribs where alae have eroded. Blades about 1 cm wide (rarely to 2-3 cm), with midrib but no lateral veins, branched irregularly from the midrib. Growth from apical cell, with development of primary, secondary and tertiary cell rows, cortication starting near apex. Thallus polystromatic; medulla of mixed larger and smaller cells, with indistinct central filament, cortex of small cells. Reproductive structures in small foliaceous rosettes, scattered over blades on either side of midrib.

Collections, ecology and regional distribution

Recorded from Brandfontein, just west of Cape Agulhas (Stegenga et al. 1997) to Kei Mouth area (22-43). Subtidal and epilithic.

World distribution: South African endemic.

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

Holmesia capensis, Port Alfred (lens cap = 50 mm diameter).

Holmesia capensis. 1. Habit. 2. Apex (of male proliferation). 3. Cross section. Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Delesseriaceae

Hypoglossum imperfectum Stegenga, Anderson and Bolton 2001: 157

Plants red, minute (to about 5 mm), comprising creeping blades bearing slightly larger lateral to upright blades. Creeping axes foliar, comprising lanceolate to ovate sections up to 1.2 mm long and 0.5 mm wide, separated by regular constrictions where tufts of multicellular rhizoids arise ventrally (mainly from the blade wings) and attach thallus to the substratum. Lateral blades arising endogenously at constrictions from dorsal sides of the midrib, usually in slightly to very unequal pairs. Laterals either developing into new creeping blades or into upright blades that remaining unbranched and becoming fertile. Fertile blades generally larger (to 3.3 mm long and 1.6 mm wide) than creeping blades, and with blunt to slightly depressed apices. Blades monostromatic except for midrib and reproductive sori.

Tetrasporangia about 45 µm in diameter, tetrahedrally divided, arranged in single elongate sorus per blade, covering most of blade length and about one third of width. Mature cystocarps not seen.

Collections, ecology and regional distribution

Known only from a single collection growing on a Bryozoan at 24 m depth in Tsitsikamma National Park (32).

Type locality: Middelbank reef, Tsitsikamma National Park (Stegenga et al. 2001).

Hypoglossum imperfectum (stained, slide-mounted).

Hypoglossum imperfectum, detail of cells.

Hypoglossum imperfectum blade apex.

Hypoglossum imperfectum with tetrasporangial sorus.

Order Ceramiales

Family Delesseriaceae

Martensia elegans Hering 1841: 92

Plants pink to violet, often iridescent, comprising numerous fan-shaped, wavy upright blades a few cm high. Individual thalli comprise inconspicuous disc-like holdfast, short cylindrical stalk and expanded, fan-shaped blade up to 3 cm long and 5 cm wide; blade with membranous distal and basal zones and usually a median part forming a net-like mesh with square to rectangular holes; blade margins smooth to slightly uneven or dentate.

Collections, ecology and regional distribution

Recorded from Dwesa in Transkei and throughout Kwazulu-Natal (44-58). Found in intertidal pools and in the sublittoral fringe.

World distribution: East coast of Africa up to Ethiopia, also various warm temperate and tropical localities in the Indian and Pacific Oceans (Guiry & Guiry 2010).

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

Martensia elegans, Hluleka, plant at bottom left with globose cystocarps.

Martensia elegans, Hluleka, detail of cystocarps showing ostiole.

Order Ceramiales

Family Delesseriaceae

Neoholmesia natalensis M. J. Wynne 1985: 122, figs 1-13

Plants red, small (to about 4 cm high) comprising terete cartilaginous axes bearing clusters of delicate blades. Terete axes 2-4 mm diameter; medulla of un-pigmented mixed small and large cells and cortex of small pigmented cells. Blades to 1.3 cm long and 0.8 cm wide, membranous, ovate to elongate-ovate, margins entire or dentate; polystromatic except near apex and margins, about 125-135 µm thick except near margins and midline; thickened near midline but no conspicuous midrib present. Wings of blade eroding with age, thickened midline persisting as a cartilaginous axis. Tetrasporangia tetrahedrally divided, up to 50 µm diameter, arranged in sori on adaxial sides of blades that arise from thickened axes; sori palisade-like on account of elongate cells that bear the tetrasporangia. Gametophytes unknown.

Collections, ecology and regional distribution

Recorded from Stilbaai area to Park Rynie in southern Kwazulu-Natal (26-48). Epilithic, found in lower eulittoral and sublittoral fringe.

World distribution: South African endemic.

Type locality: Palm Beach near Port Edward, Kwazulu-Natal (Wynne 1985).

Note: see Wynne (1985) for detailed description and illustrations of structure.

Neoholmesia natalensis, tip of blade of fresh specimen (Palm beach, KZN). Width at base ca 12 mm.

Neoholmesia natalensis, A – plant with young blades regenerating on terete basal axes; B – blades growing from midrib of damaged blades; C- blades with tetrasporangia (re-drawn from Wynne 1985).

Neoholmesia natalensis, cross section of part of blade (re-drawn from Wynne 1985).

Order Ceramiales

Family Delesseriaceae

Genus Nienburgia Kylin

Stipitate membranous blades; blades strap-like with faint to distinct midrib, growth from single apical cell, thallus corticated, branching from margins or midrib, margins dentate.

Key to species

1a. Fronds strap-like, dentation simple, branching mainly from frond margins

N. serrata

1b. Fronds feathery, dentation compound to fimbriate, branching
mainly from midrib

N. pinnatifida

Note 1: Our deep-water specimens may represent a third species of Nienburgia. See note under Nienburgia serrata.

Note 2. N. serrata resembles Bartoniella crenata - for a comparison between the two, see Note 2 under N. serrata.

Order Ceramiales

Family Delesseriaceae

Nienburgia pinnatifida (Suhr) Papenfuss 1968: 275

Plants bright red, to 5 (-8) cm tall, complanate, soft, membranous, with distinct, sparsely branched main axes lined with profuse short branchlets; main axes 2-3 mm wide except where flattened alae missing, with very prominent midrib, ovate in cross section, margins compoundly dentate and elaborate, marginal teeth often fimbriate and sometimes hooked. Axes flat, irregularly dichotomously branched and with distinct midrib; overlapping, regularly alternate side branches bearing finely-feathered, short (generally 1-1.5 cm long) branches usually arising from midrib.

Ecology, collections and regional distribution

Recorded from Algoa Bay to Kowie (36-39) but probably more widespread. Epilithic in shallow sublittoral and lower eulittoral zones.

Type locality Algoa Bay (Port Elizabeth area) (Papenfuss 1968).

Note: Papenfuss (1968: 275) made the combination Nienburgia pinnatifida based on Nitophyllum pinnatifidum Suhr . He noted that Nitophyllum kowiensis Schmitz material “present in Tyson’s and Becker’s collections in the Bolus Herbarium” are the same species. Our description above is largely based on a number of Becker’s BOL specimens annotated by Papenfuss.

Nienburgia pinnatifida, Kowie.

Nienburgia pinnatifida, Kowie, showing compound dentation. Scale divisions = 1mm.

Nienburgia pinnatifida, fresh material from Port Alfred, showing detail of compound/fimbriate dentation and distinct midrib.

Order Ceramiales

Family Delesseriaceae

Nienburgia serrata (Suhr) Papenfuss 1956: 73

Plants erect, pink to red, complanate, up to 7 (-8) cm tall, with discoid or partly rhizomatous holdfast. Fronds ribbon-like, 2-3 (-4) mm wide, with faint midrib and pinnate to irregular branching from margins; margins regularly alternately dentate; dentation simple; blades often with pale blotches. Growth from a single apical cell, producing axial cell row by transverse divisions; axial cells cutting off two lateral pericentral cells; secondary cell rows developing asymmetrically and leading to alternate dentation on margins. Thallus corticated with central medulla of large cells and cortical layer(s) of small cells (single layer in wings of frond, several layers in midrib). Tetrasporangial sori on either side of midrib or covering midrib as well in a subapical sorus, mature tetrasporangia about 50 µm diameter, tetrahedrally divided. Male sori covering blade in subapical portions; cystocarps scattered on blades.

Collections, ecology and regional distribution

Recorded from Cape Hangklip to just north of Durban (19-51). Found in lower eulittoral pools and the sublitoral possibly to at least 25m (but see note 1 below).

World distribution: South African endemic.

Type locality: Algoa Bay (Port Elizabeth) (Papenfuss 1956).

Note1: Our deep-water specimens may represent a third species of Nienburgia. This entity appears to be similar to N. serrata, but smaller (up to about 2 cm tall?); blades up to 6 mm long and 3 mm wide, dentation simple, teeth smaller than in N. serrata and often rather irregular, primary midrib and side veins distinct. Tetrasporangia arranged in half-circle at top of blade, also covering axial region of blade and almost filling small proliferations, ca. 50 µm in diameter, tetrahedrally divided. Males not seen. Carposporophytes (only two seen) scattered on the blade (not on the midrib), protruding from one side, 700 µm in diameter, ostiolate, carpospores in terminal rows of 2‑4, measuring ca. 25 µm in diameter.This possible entity seems to include our few deep-water records of N. serrata (Tsitsikamma, 24 m depth and Stilbaai, 23 m depth) as well as some from the sublittoral fringe/lower eulittoral (a few sites between Jongensfontein and Xora River). The relationship between this entity and N. serrata needs further study.

Note 2: N. serrata resembles Bartoniella crenata, but does not have branches arising from the midrib. Also, in B. crenata the teeth are small (up to 20/cm), the midrib is distinct, the thallus irregularly constricted, often branchlets arise from the midrib, and the secondary and tertiary cell rows reach the margin of the blade. In Nienburgia serrata the teeth are larger (5-10/cm), the midrib indistinct/faint, there are no constrictions in the thallus, and only the secondary cell rows reach the margin of the blade.

Nienburgia serrata, Three Sisters (BOL).

Nienburgia serrata, Nature’s Valley (BOL), showing typical simple dentation.

Nienburgia serrata. 1. Habit. 2. Cross section. 3. Thallus apex. Reproduced from Stegenga et al. (1997).

Nienburgia sp? Specimens from 24m depth, Tsitsikamma. See note 1 under N. serrata.

Nienburgia sp? Detail of irregular dentation. Tsitsikamma, 24 m (BOL). See note 1 under N. serrata.

Order Ceramiales

Family Delesseriaceae

Papenfussia  Kylin

Plants foliaceous, growing from transversely divided apical cells; primary cell row with intercalary divisions. Thallus becoming polystromatic, in section showing regular horizontal and vertical cell rows; veins absent. Tetrasporangial sori and cystocarps scattered over the submarginal part of the thallus; carposporophytes with terminal carposporangia. This genus includes the South African species previously ascribed to Pollexfenia : for nomenclatural reasons they must be assigned to Papenfussia (Womersley 2003).

Key to species

1a. Plants elongate, flabellate, up to 15 cm long

P. laciniata

1b. Plants with more or less circular outline, more or less incised, up to 3 cm tall

P. minuta

Order Ceramiales

Family Delesseriaceae

Papenfussia laciniata (Harvey) Kylin 1956: 444

Plants dark red, often with pale spots near apices, up to 15 cm tall, when fresh often strikingly marked with patterns of pale bluish to silvery iridescence; thallus comprising small prostrate basal part bearing irregularly branched fan-shaped blades; blades up to 1 cm wide, without veins or midrib, apical margins dentate. Growth by transverse divisions from an apical cell; primary cell rows with intercalary divisions that become obscured. Thallus polystromatic except near apices; in cross-section showing regular horizontal rows of uniform cells up to about 50 µm long; outer layer of smaller (to 35 µm long) vertically-orientated cells. Tetrasporangia in elongated sori along margins of blades. Cystocarps scattered over surface of blades.

Collections, ecology and regional distribution

Recorded from the southern Cape Peninsula to the Kei Mouth area (16-43). Epilithic in the lower eulittoral.

World distribution: South African endemic.

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

Note: According to Stegenga et al. (1997) (as Pollexfenia laciniata), and from our observations, this species is often very similar to P. minuta, and they may be conspecific.

Papenfussia laciniata, Natures Valley.

Papenfussia laciniata, frond shape.

Papenfussia laciniata, cystocarps (round, dark areas).

Papenfussia laciniata, tetrasporangial sori (dark spotted areas around some blade edges).

Papenfussia laciniata. Habit, tetrasporangial. 2. Thallus margin near apex. 3. Cross section. Reproduced from Stegenga et al. (1997)(as Pollexfenia laciniata).

Order Ceramiales

Family Delesseriaceae

Papenfussia minuta Kylin 1938: 17, pl. 5: fig. 15

Plants bright red, often with pale spots, up to 3 cm tall, comprising small prostrate basal part, sometimes short stipe, and almost circular blades a few to 7 (-8) mm in diameter. Blades incised and with dentate margins from which proliferations sometimes arise. Anatomy and mode of growth as in P. laciniata. Tetrasporangia in circular sori in subapical areas of blade. Cystocarps not seen.

Collections, ecology and regional distribution

Recorded from Hangklip (120 km west of Cape Agulhas) to about 40 km north of Durban (19-52). Epilithic or epiphytic in lower eulittoral, in pools and algal turfs.

World distribution: South African endemic.

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

Note: may be conspecific with P. laciniata (Stegenga et al. 1997, as Pollexfenia ).

Papenfussia minuta. Habit of small plants: tetrasporangial (on left) and male (on right). Margin of plants with spermatangial sorus (below). Reproduced from Stegenga et al. (1997) (as Pollexfenia minuta).

Order Ceramiales

Family Delesseriaceae

Platysiphonia delicata (Clemente y Rubio) Cremades 1990: 492

Plants lax, delicate, red, comprising horizontal basal axes bearing soft, compressed upright axes to several cm high, forming short turfs. Horizontal basal axes terete, up to 200 µm diameter, attached by unicellular rhizoids. Upright axes flattened, up to 100 µm wide, laxly branched from midrib; composed of central axial filament with two transverse and two lateral pericentral cells, the latter each forming two flanking cells; cortication present only in most proximal parts and then poorly developed. Tetrasporangia borne in stichidia up to 1 mm long and 170 µm wide, arranged distichously in up to 20 fertile segments, cut off from lateral pericentrals and covered by 2 cover cells and 4 flanking cells. Spermatia borne in stichidia similar to those bearing tetrasporangia. Cystocarps without stalk, flask-shaped when mature, to 800 µm long and 550 µm diameter, with single prominent ostiole.

Collections, ecology and regional distribution

Recorded from De Hoop along the south and east coasts to northern Kwazulu-Natal (24-58). A common component of algal turfs or epiphytic on other seaweeds, in lower eulittoral pools, sublittoral fringe and down to at least 10 m depth.

World distribution: widespread in the warm temperate eastern Atlantic, along the African east coast to Kenya. Also in India, Oman, Iran, Australia and Brazil (Guiry & Guiry 2013).

Type locality: Cadiz, Spain (Silva et al. 1996).

Note: This species, which was previously called P. miniata (C. Agardh) Børgesen, is distinguished from the larger west coast Platysiphonia intermedia (Grunow) Wynne which has 2 rather than 4 flanking cells in tetrasporangial stichidia. (see Stegenga et al. 1997).

Platysiphonia delicata, attached to Corallina sp. In tide pool, Kenton on Sea.

Platysiphonia delicata, horizontal axis with rhizoids (underneath), bearing erect axes.

Platysiphonia delicata, detail of erect axes.

Platysiphonia delicata, tetrasporangia (Nature’s Valley).

Platysiphonia delicata, with developing flask-shaped cystocarps.

Order Ceramiales

Family Delesseriaceae

Taenioma perpusillum (J. Agardh) J. Agardh 1863: 1257

Plants dark brown to blackish, minute (to a few mm tall), with prostrate and erect portions. Main axes terete, with central filament and 4 pericentral cells per segment. Prostrate axes terete, 120-140 µm in diameter, attached by unicellular rhizoids or haptera arising from pericentral cells. Erect axes with alternately arranged determinate laterals that are compressed and about 120 µm wide, the lateral pericentral cells each bearing two flanking cells, the transverse pericentrals remaining undivided; the apex of each branch bearing three conspicuous multicellular hairs, each composed of one to several elongated cells. Reproductive structures not seen.

Collections, ecology and regional distribution

Recorded from the relatively warm waters of Langebaan Lagoon in the Western Cape, and then from De Hoop along the south and east coasts to northern Kwazulu-Natal (23-58). Found in algal turfs in the lower eulittoral.

World distribution: worldwide in warm temperate and tropical seas. Fertile material seems to be rare worldwide (Stegenga et al. 1997).

Type locality: Oaxaca, Mexico (Silva et al. 1996).

Note: This species should not be confused with vegetative plants of Platysiphonia delicata, which lack the three uniseriate hairs on each upright axis.

Taenioma perpusillum. 1. Microscopic habit. 2. Apex of branchlets, showing terminal hairs. Reproduced from Stegenga et al. (1997).

Order Ceramiales

Family Delesseriaceae

Valeriemaya seagriefii De Clerck, Wynne and Stegenga 2002: 199-204

Plants bright red, to 16 (-35) mm tall, with well-developed rhizomatous basal system and stipitate upright blades. Rhizomatous stolons branched, 500-700 µm diameter; blades ovate to oblong, simple or sometimes bifurcate, 2-4 (-6) mm wide, 8-20 (-30) mm long; blades arising from basal system or stipes or from blade margins, monostromatic and 70-85 µm thick except for indistinct midrib region which is up to 300 µm thick, blade apices broadly rounded, margins entire. Tetrasporangial sori paired on each side of midrib, or single large ovate sorus varying in position on blade; tetrasporangia tetrahedrally divided; cystocarps scattered over surface of blade.

Collections, ecology and regional distribution

Recorded from Glencairn in False Bay to Hluleka, Transkei (17-45). Found from intertidal pools to the shallow sublittoral, but most common as a turf component on vertical surfaces in the lower eulittoral (De Clerck et al. 2002).

World distribution: South African endemic (De Clerck et al. 2002).

Notes: 1. This species is named after the late Professor S. C. Seagrief, who made important contributions to our knowledge of South African seaweeds.

2. V. seagriefii was previously recorded from Hluleka, Transkei as “Delesseriaceae indet. (Bolton & Stegenga 1987), as Erythroglossum sp. from the Eastern Cape (Seagrief 1988) and as Erythroglossum sp. indet. from the Western Cape (Stegenga et al. 1997).

Valeriemaya seagreafii, isotype specimens (BOL), from Bat’s Cave, East London.

Valeriemaya seagreafii, isotype specimens (BOL), Bat’s Cave, East London.

Valeriemaya seagriefii. 1. Habit. 2. Detail of thallus margin. 3. Cross section. 4 Thallus apex. Reproduced from Stegenga et al. (1997) (as Erythroglossum sp. indet.).

Order Ceramiales

Family Inkyuleeaceae

Inkyuleea beckeri (F.Schmitz ex Mazza) H.-G.Choi, Kraft & G.W.Saunders 2000: 285

Plants up to 10 cm tall, dark red, more or less spreading horizontally, though not frequently secondarily attached. Thallus with strong main axes, regularly three determinate branchlets per segment and infrequent indeterminate axes. Determinate branchlets dimorphic: one large branchlet and two smaller branchlets, the occasional indeterminate branch replacing the large determinate branchlet. Main axis up to 250 µm broad, naked apart from the occasional filaments that grow downwards from the basal cells of all three laterals. All three branchlets with a short basal cell, the other cells about twice as long as broad. The basal cell with one or a few small ramuli, the other cells in the large branchlet with three laterals basally – one or two strictly pinnately branched, the other(s) simple or little branched; two laterals more toward the apex. The two smaller branchlets usually with two simple, occasionally re-branched, laterals. Especially the large branchlets strongly incurved. Tetrasporangia mainly in branched clusters on proximal segments of the ramuli of large branchlets, but also in similar clusters on the basal segments of smaller branchlets. Tetrasporangia oval, ca. 35 x 30 µm, cruciately divided, the first division being horizontal. Other reproductive specimens not seen.

Collections, ecology and regional distribution

Recorded from Port Alfred to northern KwaZulu-Natal (39-56). On the south coast very common only at Mzamba, where most material was attached in the lower intertidal. Otherwise mainly found in drift in the east of the area (see also De Clerck et al. 2005).

World distribution: South African endemic.

Type locality: Mouth of Kowie River, Port Alfred, South Africa (Silva et al. 1996).

Inkyuleea beckeri (photo H. Verbruggen, from De Clerck et al. 2005).

Inkyuleea beckeri, part of thallus showing feathery appearance.

Inkyuleea beckeri, detail of sterile thallus, Mzamba (Stained slide).

Inkyuleea beckeri, detail of branchlets. Mzamba specimens, stained slide.

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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 CALLITHAMNIACEAE

Callithamnion collabens

Callithamnion cordatum

Callithamnion granulatum

Callithamnion hookeri

Callithamnion stuposum

Callithamnion tripinnatum

Callithamnion sp.1

Callithamnion sp.2

Crouania attenuata

Crouania francescoi

Euptilota mollis

Heteroptilon pappeanum

FAMILY CERAMIACEAE

Acrothamnion preissii

Amoenothamnion lycopodioides

Antithamnion diminuatum

Antithamnion hubbsii

Antithamnionella spirographidis

Antithamnionella ternifolia

Antithamnionella tormentosa

Antithamnionella verticillata

Antithamnionella sp.

Bornetia repens

Callithamniella capensis

Callithamniella tingitana

Carpoblepharis flaccida

Centroceras genus

Centroceras spp. (ex “clavulatum”)

Ceramium aff. callipterum

Ceramium arenarium

Ceramium camoui

Ceramium centroceratiforme

Ceramium glanduliferum

Ceramium graecum-lenticulare

Ceramium juliae

Ceramium obsoletum

Ceramium planum

Ceramium poeppigianum

Ceramium tenerrimum

Ceramium sp.1

Ceramium sp.2

Ceramium sp.3

Compsothamnionella sciadophila

Episporium centroceratis

Gayliella dawsonii (= Ceramium dawsonii)

Gayliella papenfussiana (= Ceramium papenfussianum)

Gayliella transversalis

Laurenciophila minima

Microcladia exserta

Microcladia gelidii

Perischelia glomulifera

Pterothamnion recurvatum

Pterothamnion sp.

Ptilothamnion codicola

Ptilothamnion goukammae

Ptilothamnion polysporum

Scageliopsis tsitsikammae

Syringocolax macroblepharis

Zonariophila semiendophytica

FAMILY DASYACEAE

Dasya echinata

Dasya scoparia

Dasya sp.1

Dasya sp.2

Dasya sp.3

Dipterocladia pinnatifolia

Heterosiphonia arenaria

Heterosiphonia crispa

Heterosiphonia dubia

FAMILY DELESSERIACEAE

Acrosorium acrospermum

Acrosorium ciliolatum

Acrosorium maculatum

Apoglossum ruscifolium

Apoglossum spathulatum

Bartoniella crenata

Caloglossa leprieurii

Gonimophyllum africanum

Holmesia capensis

Hypoglossum imperfectum

Martensia elegans

Neoholmesia natalensis

Nienburgia pinnatifida

Nienburgia serrata

Papenfussia laciniata

Papenfussia minuta

Platysiphonia delicata

Taenioma perpusillum

Valeriemaya seagriefii

FAMILY INKYULEEACEAE

Inkyuleea beckeri

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.