Seaweeds of the South African South Coast

Book 2: Class Phaeophyceae (Brown Seaweeds)

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

2018

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 © 2018 Robert Anderson et al. All rights reserved.

Copyright © 2018 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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INTRODUCTION TO THE PHAEOPHYCEAE

The group commonly known as the brown algae were formerly classified in the phylum Phaeophyta, but this classification has been reconsidered within the last few years. DNA sequencing and cell microstructure places them close to groups of microscopic algae such as diatoms, unrelated to the other two main groups of seaweeds. The similarities between the main groups of seaweeds are related to their habitat and range of forms, rather than evolutionary links.

Unlike red and green algae, there are no known single-celled brown algae; all are multicellular, and the vast majority are seaweeds, with very few freshwater forms. Brown algae include the largest and most complex forms in the algae with, for example, species of Sargassum having differentiated holdfasts, complicated systems of branching, and separate leaf-like blades, easily visible floats (vesicles) and obvious branched reproductive structures (receptacles).

The brown marine macroalgae (seaweeds) occur on all rocky seashores, throughout the world, although there are generally fewer species than red algae except in cooler waters of the northern Hemisphere. In South Africa overall the brown algae represent less than 15% of seaweed species, less than on similar temperate shores on other continents (Bolton 1996). Nevertheless, they are prominent in inshore ecosystems, including the largest individual seaweeds; the longest seaweed measured in South Africa was a west coast kelp (Ecklonia maxima) measuring 17m in total length. On the south coast the largest of the brown algae reach more than 1m in length, and are in two orders: the Laminariales and the Fucales. The Laminariales, often referred to as ‘kelps’, are represented by two species of Ecklonia. The small kelp Ecklonia radiata forms a fringe just below the low tide mark on many south coast shores, and occurs in deeper waters as far north as southern Mozambique. The larger ‘sea bamboo’, Ecklonia maxima, forms large kelp forests on the west coast, but was absent from the south coast until it appeared at De Hoop Nature Reserve in 2006/7 (Bolton et al. 2012). The Fucales include a number of species of the worldwide genus Sargassum, which are often dominant in mid-intertidal rock pools. In addition, there are some interesting single-species genera of Fucales, endemic to Southern Africa, including Bifurcariopsis, Oerstedtia and Anthophycus, which can also dominate the shallow subtidal and large rock pools.

The Dictyotales are a large order of mostly tropical brown algae, which become more dominant on south coast shores moving eastwards. They are generally flattened and branched, are characterised by growth from large cells, singly or in rows, at the apex of the plant, and include multi-species genera such as Dictyota, Dictyopteris,Zonaria, Padina. Some species of Dictyota (e.g. D. naevosa, D. humifusa) are spectacularly colourful in rock pools, due to their refraction of light under water (iridescence). Some smaller brown algae have a fine threadlike growth form, occurring as furry growths on other seaweeds (epiphytes such as Feldmannia, Hinksia), although these are less common than on other seashores around the world. The similarly threadlike genus Ectocarpus can be very abundant in estuarine lagoons. Species of the genera Ralfsia and Zeacarpa occur as ‘crusts’; a thin layer of cells closely adherent to seashore rock.

There is no economic utilisation of brown algae on the South African south coast, with populations of larger species not sufficient to warrant harvesting, unlike the large kelp forests on the west coast.

SYSTEMATIC CLASSIFICATION OF SOUTH COAST PHAEOPHYCEAE

Order Ectocarpales

ACINETOSPORACEAE

Acinetospora crinita
Feldmannia globifera
Feldmannia irregularis
Feldmannia sp. 1
Feldmannia sp. 2
Hincksia granulosa
Hincksia mitchellae
Hincksia sandriana

ASTEROCLADACEAE

Asterocladon rhodochortonoides

BACHELOTIACEAE

Bachelotia antillarum

ECTOCARPACEAE

Ectocarpus fasciculatus
Ectocarpus siliculosus

CHORDARIACEAE

Asperococcus bullosus
Elachista sp.
Elachistiella endarachnae
Leathesia marina
Leptonematella fasciculata
Levringia filiformis
Myriocladia capensis
Myriogloea papenfussii
Stilophora flanaganii
Streblonema codii

CHORDARIOPSIDACEAE

Chordariopsis capensis

SCYTOSIPHONACEAE

Chnoospora minima
Colpomenia sinuosa
Iyengaria stellata
Petalonia binghamiae
Petalonia fascia
Rosenvingea intricata

Order Nemodermatales

ZEACARPACEAE

Zeacarpa leiomorpha

Order Chordariales

NEORALFSIACEAE

Neoralfsia expansa

RALFSIACEAE

Ralfsia verrucosa

Order Scytothamnales

SPLACHNIDIACEAE

Splachnidium rugosum

Order Sphacelariales

SPHACELARIACEAE

Sphacelaria brachygonia
Sphacelaria rigidula
Sphacelaria tribuloides

STYPOCAULACEAE

Halopteris filicina
Halopteris funicularis
Phloiocaulon suhrii

Order Dictyotales

DICTYOTACEAE

Dictyopteris ligulata
Dictyopteris macrocarpa
Dictyopteris serrata
Dictyota dichotoma
Dictyota liturata
Dictyota naevosa
Dictyota sp.
Exallosorus harveyanus
Lobophora variegata
Padina boryana
Rugulopteryx suhrii
Stypopodium multipartitum
Zonaria subarticulata
Zonaria tournefortii

Order Cutleriales

CUTLERIACEAE

Aglaozonia (see Cutleria)
Cutleria multifida

Order Sporochnales

SPOROCHNACEAE

Carpomitra costata
Carpomitra longicarpa

Order Laminariales

LESSONIACEAE

Ecklonia maxima
Ecklonia radiata

Order Fucales

BIFURCARIOPSIDACEAE

Bifurcariopsis capensis

SARGASSACEAE

Anthophycus longifolius
Brassicophycus brassicaeformis
Cystophora fibrosa
Oerstedtia scalaris
Sargassum elegans
Sargassum incisifolium
Sargassum cymosum var scabriusculum

Note: names were checked and updated on AlgaeBase (Guiry & Guiry 2017) on 19 October 2017. Any subsequent changes will not be reflected here unless noted under a particular species.

CLASS PHAEOPHYCEAE – KEY TO THE SOUTH COAST GENERA

1a. Thallus largely endophytic in bigger algae

Streblonema

1b. Thallus epilithic, epizoic or epiphytic, sometimes with an endophytic base

2

2a. Thallus prostrate or crustose, without free erect parts

3

2b. Thallus with free erect parts

6

3a. Thallus prostrate, not strongly adherent to substratum, elevated by multicellular rhizoids

Cutleria (Aglaozonia phase)

3b. Thallus crustose, strongly adherent to substratum, with or without rhizoids

4

4a. Unilocular sporangia borne laterally in clusters on free paraphyses

Zeacarpa

4b. Unilocular sporangia borne terminally , immersed in a solid layer of paraphyses

5

5a. Anatomy of upward-curving filaments with no distinct cortical zone, unilocular sporangia sessile or on single-celled pedicel

Ralfsia

5b. Distinct cortex of vertical filaments above upward-curving medullary filaments, unilocular sporangia on pedicles of 3-6 cells

Neoralfsia

6a. Erect thallus consisting of uniseriate filaments

7

6b. Erect thallus of more complex morphology and anatomy

15

7a. Thallus of pseudoparenchymatous basal cushion bearing loose erect filaments, erect filaments uniseriate but plurilocular sporangia divided longitudinally (multiseriate)

8

7b. Thallus entirely uniseriate filamentous)

10

8a. Plurilocular sporangia terminal or lateral, never intercalary

Elachista

8b. Plurilocular sporangia intercalary or terminal and intercalary on same thallus

9

9a. Thallus tiny (to 0.5mm tall), basal cushion of well-developed medulla, cortex of upright assimilatory filaments

Elachistiella

9b. Thalli to 2.5 mm tall, basal disc of branched radial filaments bearing erect assimilatory filaments that are simple or branched basally

10

10a. Sporangia intercalary, sometimes divided longitudinally

Bachelotia

10b. Sporangia terminal or lateral, never intercalary

11

11a. Chloroplasts one or a few per cell, ribbon-shaped

Ectocarpus

11b. Chloroplasts discoid or stellate, several per cell

12

12a. Chloroplasts stellate, thallus comprising creeping basal filaments bearing erect filaments

Asterocladon

12b. Chloroplasts discoid, numerous

13

13a. Lateral branches inserted at almost right angles, sporangia with relatively large loculi (10-15 µm diameter)

Acinetospora

13b. Lateral branches inserted at relatively acute angles, sporangia with relatively small loculi (ca 5 µm diameter or less)

14

14a. Erect filaments profusely branched, meristematic zones at bases of each lateral, sporangia above and below meristems

Hincksia

14b. Erect filaments sparsely branched (near bases), meristematic zones at bases of erect filaments, sporangia borne near bases of filaments below meristems

Feldmannia

15a. Thallus a more or less globose mass, solid or hollow

16

15b. Thallus of a different shape

18

16a. Thallus clearly pseudoparenchymatous in structure

Leathesia

16b. Thallus parenchymatous in structure

17

17a. Thallus hollow, thin-walled (ca 6-7 cell layers)

Colpomenia

17b. thallus solid, thick-walled (at least 10 cell layers)

Iyengaria

18a. Thallus tubular, unbranched, like hollow skin

Asperococcus

18b. Thallus of a different shape

19

19a. Thallus forming tangles or tangled cushions of terete to slightly flattened, branched axes

20

19b. Thallus of a different shape

22

20a. Thallus solid, medulla of large cells, cortex of small pigmented cells

Chnoospora (in part)

20b. Thallus hollow

21

21a. Thallus very flaccid, forming loose tangles on estuarine vegetation, assimilatory filaments present on surfaces of apical branches

Stilophora

21b. Thallus forming fairly compact cushions, no assimilatory filaments present

Rosenvingea

22a. Thallus solid, branched, terete, up to 1 mm diameter and to 50 cm tall, with conspicuous terminal tufts of assimilatory filaments

Carpomitra

22b. Thallus without terminal tufts of assimilatory filaments

23

23a. Thallus without distinctly flattened parts of blades

24

23b. Thallus with either flattened axes or blades

37

24a. Ultimate branches clearly polysiphonous

25

24b. Ultimate branches not polysiphonous

29

25a. Branching regular, either opposite or alternate

26

25b. Branching more irregular

28

26a. Branching regularly opposite, pinnate

Battersia

26b. Branching regularly alternate, distichous

27

27a. Plants to 30 cm tall, main axes terete, ca. 1 m diameter, with uncorticated determinate laterals3-4 mm long in feather-like tufts

Phloiocaulon

27b. Plants to 3 cm tall, main axis ca. 100 µm diameter, whole thallus feather-like

Halopteris (in part)

28a. Plants (local species) rarely longer than 2 cm, lateral branches originating from sub-apical segments

Sphacelaria

28b. Plants to 10 cm or longer, lateral branches originating from lenticular cells cut off from the apical cell

Halopteris (in part)

29a. Thalli with a soft central core and mantle of free assimilatory filaments

30

29b. Plants solid, without free assimilatory filaments

32

30a. Axes 4-6 mm in diameter, central core rather loose

Myriogloea

30b. Axes 2-4 mm in diameter, central core fairly firm

31

31a. Thallus profusely branched in three orders, branches of third order fairly short (a few to 20 mm)

Myriocladia

31b. Thallus sparsely branched, branches arising near base

Levringia

32a. Main axes up to 0.5 mm thick, with many unbranched laterals

Chordariopsis

32b. Main axes 1mm thick or thicker, laterals not plentiful or crowded

33

33a. Axes and laterals up to ca. 1 cm thick, with leathery skin, mucilaginous core

Splachnidium

33b. Axes between 1 and 5 mm thick

34

34a. Axes 1-2 mm thick, fairly lax

35

34b. Axes more than 2 mm thick, tough

36

35a. Thalli up to 8 cm tall, terete to compressed, holdfast rhizoidal, fertile portions not visible to naked eye

Chnoospora (in part)

35b. Thalli up to 50 cm tall, fibrous, terete, holdfast conical, fertile thalli with obvious swollen receptacles in apical portions

Cystophora

36a. Holdfast branched, rhizomatous, axes fairly lax, to 2-3 mm diameter

Brassicophycus

36b. Holdfast conical, axes stiff, main axes to 5 mm diameter

Bifurcariopsis

37a. Plants consisting of short, simple blades, lanceolate to strap-shaped

Petalonia

37b. Plants with more complex external differentiation

38

38a. Plants (sub) dichotomously branched, fan shaped and variously cleft, or funnel-shaped

39

38b. Plants of a different branching type

45

39a. Plants with a broad apical meristematic zone

40

39b. Meristem of a single large apical cell or small apical region

44

40a. Fronds funnel-shaped, up to 2 cm diameter, with distinct concentric lines and whitish calcified upper layer

Padina

40b. Fronds (sub) dichotomously branched or fan-shaped

41

41a. Fronds strap-shaped, 2-5 mm wide and to 30 cm long, repeatedly branched

Zonaria

41b. Fronds fan-shaped, erect or decumbent

42

42a. Plants erect, to 30 cm tall, fronds broad fan-shaped, cleft, often with bluish iridescence, hair cells forming distinct concentric bands

Stypopodium

42b. Fronds a few to 6 cm long, lobed, fan-shaped, erect or decumbent

43

43a. Fronds without hair tufts, medulla of four cell layers, cortex of single cell layer on each surface

Exallosorus

43b. Fronds with hair-tufts in concentric zones, medulla a single layer of large cells, cortex of 2-4 cell layers on each surface, upper cortical cells forming visible longitudinal lines

Lobophora

44a. Plans with prominent midrib

Dictyopteris

44b. Plants without midrib

Dictyota

45a. Plants with holdfast of branched haptera and single stipe bearing large flat blade, sori visible as pale slightly raised areas

Ecklonia

45b. Plants with discoid/conical holdfast bearing one to several branched upright axes with many blades, reproductive structures (receptacles) on specialised branches

46

46a. Thalli strongly compressed in almost all parts, primary laterals in alternate, distichous arrangement imparting a zig-zag appearance to thallus

Oerstedtia

46b. Plants with branched upright axes bearing many flat leaf-like blades, flotation vesicles present

47

47a. Axes cylindrical or triangular in section, leaves a few to about 7 cm long

Sargassum

47b. Axes flattened in cross-section, leaves strap-shaped and to 20 cm long

Anthophycus

Order Ectocarpales

Family Acinetosporaceae

Acinetospora crinita (Carmichael) Sauvageau 1899: 118

Plants comprising a tangled mass of fairly sparsely branched uniseriate filaments up to 25 mm long. Cells of main axis ca. 30-60 µm long x 15-25 (-40) µm broad: main axis bearing slightly incurved shorter laterals centrally on the parent cell. Growth of main axis generally diffuse, with meristematic regions towards the base of shorter laterals. Cells of laterals to 20 µm long x 15 µm maximum diameter, tapering to a false hair ca. 10 µm in diameter composed of 3-5 elongated cells. Numerous discoid plastids per cell.

Plurilocular sporangia sessile or with a one-or two-celled stalk, produced from centre of parent cell, occasionally terminal, 80-100 µm long, 25-35 µm diameter, with few (to ca. 20) loculi, tapering. No other reproductive structures seen.

Collections, ecology and regional distribution

Found in mixed turfs on intertidal algae. Recorded from False Bay (Western Cape) to the East London area (17-41).

World distribution: widespread in tropical and temperate Atlantic, Mediterranean, also Australia, New Zealand, Japan (Guiry & Guiry 2017).

Type locality: Scotland (Womersley 1987).

Note: Stegenga et al (1997) point out that this could be a phase in the life history of another ectocarpoid.

Acinetospora crinita, general view, stained slide material

Acinetospora crinita, detail showing plurilocular sporangium (stained slide material)

Acinetospora crinita. Top – microscopic habit; middle - detail of subapical (hairlike) part of erect filament; below – plurilocular sporangia (reproduced from Stegenga et al. 1997).

Order Fucales

Family Sargassaceae

Anthophycus longifolius (Turner) Kützing 1849: 605

Plants dark brown to yellowish-brown, up to about 1 m long, comprising conical holdfast to 2 cm wide that bears one to several perennial main axes up to 18 cm long, foliose when young, somewhat condensed compared to upper branches. Primary laterals branching distichously from margins of main axes, but main axes often becoming terete and appearing to bear branches radially (Jensen 1974). Main axis bearing several primary laterals annually that drop off leaving stumps up to 2 mm long. Primary laterals up to 60 cm long and varying in width from 0.5 – 4.5 cm, irregularly or regularly serrated, foliose, strongly compressed with obvious midrib.

Fertile secondary laterals bearing many branched narrow (up to maximum ca. 1 mm diameter) terete axes bearing clusters of short (to ca. 1mm) terete elongate receptacles. These receptacular branchlets arise in the axils of subtending leaves, with several of them bearing a single ovoid vesicle proximally. Each vesicle often bearing a single leaflet apically.

Collections, ecology and regional distribution

Recorded from Platboombaai, just west of Cape Point, eastwards along the entire coast and into Mozambique (17-58). A subtidal species that can form large beds at depths from a few to at least 10 m, sometimes found in rock pools and the lower eulittoral.

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

Type locality: In the Indian Ocean (Silva et al. 1996).

Note: formerly known as Sargassum longifolium (Turner) C. Agardh, Anthophycus was re-instated as separate from Sargassum by Jensen (1974), a conclusion borne out by the molecular study of Draisma et al. (2010).

Anthophycus longifolius, rather yellow plants in a rock pool, Double Mouth near Morgan Bay.

Anthophycus longifolius, whole plant, in a rock pool, Double Mouth near Morgan Bay.

Anthophycus longifolius, a stand of battered plants on intertidal platforms, Double Mouth near Morgan Bay.

Anthophycus longifolius, part of a thallus showing detail of receptacular branchlets and vesicles.

Anthophycus longifolius. 1. Fertile branch of mature plant. 2. Habit of juvenile plant. Reproduced from Stegenga et al. (1997).

Order Ectocarpales

Family Chordariaceae

Asperococcus bullosus J.V.Lamouroux 1813: 277, pl. 12: fig. 5

Plants brown to yellow-brown, membranous, hollow, resembling empty sausage skins, up to 30 cm long and 2-3 (-5) cm in diameter, with very short stipe and small holdfast. Membranous 'skin' comprising 3-5 cell layers; a cortex of 1-2 layers of small pigmented cells overlying a medulla of larger cells that increase in size towards the inside; phaeophycean hairs present. Cortical cells isodiametric in XS, 20-30 µm in size, each containing several discoid plastids with 1-2 pyrenoids.

Reproductive structures not seen in our material. Unilocular sporangia reported as scattered in sori, rounded to clavate, 30-40 µm long; plurilocular sporangia 40-60 µm long.

Collections, Ecology and regional distribution

Estuarine on our coast, usually attached to sand grains and pieces of shell, but also loose. Recorded from Nature's Valley Estuary to Double Mouth, near Morgan Bay (31-43).

World distribution

Widespread in sheltered tropical and warm temperate localities (Guiry & Guiry 2011).

Type locality: Mediterranean coast of France (Silva et al. 1996).

Note: See Womersley (1987) for a detailed description and illustrations of this species.

Asperococcus bullosus, Double Mouth Estuary, largest specimen ca. 20 cm long.

Asperococcus bullosus, cross section showing cortex and medulla.

Order Asterocladales

Family Asterocladaceae

Asterocladon rhodochortonoides (Børgesen) Uwai, Nagasato, Motomura & Kogame 2005: 193

Plants tiny, up to several mm long, epiphytic on various algae; filamentous, uniseriate, comprising creeping and upright filaments. Growth apical and diffuse; Cells 7-13 µm in diameter, 2-3 (-4) times as long as broad; branching sparse. Several chloroplasts per cell, in stellate arrangement, with central pyrenoid. Plurilocular sporangia terminal, elongated ovate to clavate, 65-100 µm long and about 20 µm in diameter at widest. Unilocular sporangia unknown.

Collections, ecology and regional distribution

Epiphytic on various large algae, especially Sargassum species. Recorded from the Plettenberg Bay area to Durban (31-51).

World distribution: scattered temperate and tropical localities almost worldwide (Guiry & Guiry 2011).

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

Note: Previously referred to as Asteronema rhodochortonoides (Børgesen) D.G.Müller & E.R.Parodi. Details of chloroplasts of cultured material from Port Elizabeth described by Müller and Parodi (1994). A specimen from Hluleka with a terminal plurilocular sporangium (as Ectocarpus rhodochortonoides), is illustrated in Bolton and Stegenga (1987).

Asterocladon rhodochortonoides, Tanzanian specimen re-drawn from Jaasund (1976, Fig. 74).

Order Scytothamnales

Family Bachelotiaceae

Bachelotia antillarum (Grunow) Gerloff 1959: 38

Plants brown, 1-2 cm tall, filamentous, uniseriate; tangled mass of branched basal filaments giving rise to straight, usually unbranched erect filaments 30-40 µm in diameter, tapering slightly towards apex. Meristematic zones reasonably distinct. In west coast specimens, cells of erect filaments rectangular, 50 – 100 µm long, containing two distinctive stellate plastids, but in Eastern Cape material the cells are often shorter and have single plastids. Unilocular sporangia in intercalary series, occasionally with longitudinal divisions into two sporangia side-by-side. Sporangia barrel-shaped. Filaments in fertile sections up to 50 µm thick.

Collections, ecology and regional distribution

Common in rock pools higher on the shore, and supralittoral rocks in splash zone, often forming a loose sand-binding turf . Recorded from False Bay to northern Kwazulu-Natal (17-58).

World distribution: Widespread in temperate and tropical waters (Guiry & Guiry 2011).

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

Bachelotia antillarum, Double Mouth, fresh material.

Bachelotia antillarum, filament with unilocular sporangia, Nature's Valley, high intertidal pool.

Bachelotia antillarum, filaments with meristematic zones (very short, dividing cells), Nature's Valley, high intertidal pool.

Bachelotia antillarum, . 1. Microscopic habit. 2. Detail of filament showing chloroplast structure (m=meristematic zone). Drawings from Stegenga et al. (1997).

Order Sphacelariales

Family Sphacelariaceae

Battersia plumigera (Holmes ex Hauck) Draisma, Prud'homme & H. Kawai 2010: 322

Plants brown, erect, up to about 1 cm high, cylindrical. Main axes and branches polysiphonous, lateral branches arising regularly; most branches determinate, a few re-branching. Main axes 50-100 µm in diameter , wider when secondary rhizoidal cortication present (in older axes), branches about half the width of main axes. Attachment in the genus is reported to be by a multi-layered basal crust.

We have only seen vegetative material, but Stegenga and Mol (1983) report that in Dutch material unilocular sporangia are globose/ovoid, borne on short branches off the main axes, in clusters; plurilocular sporangia are rather rectangular in outline; propagules are absent.

Collections, ecology and regional distribution

Recorded only in the 'Channel' at Bird Island, Algoa Bay, from the shallow subtidal (0.1-2.5 m depth) (Anderson & Stegenga 1989).

World distribution: temperate northern Atlantic, also India and Japan (Guiry & Guiry 2012).

Type locality: Eastbourne, England (Draisma et al 2010).

Note: formerly known as Sphacelaria plumigera Holmes. The genus Battersia was re-instated by Draisma et al (2010) on molecular grounds. Our record indicates that contrary to the conclusion of Draisma et al (2010), the genus Battersia is not restricted to the Northern Hemisphere.

Battersia plumigera, microscope slide specimen from Bird Island.

Battersia plumigera, tip of microscope slide specimen from Bird Island.

Battersia plumigera, branch primordial.

Battersia plumigera, detail of vegetative cells.

Order Fucales

Family Bifurcariopsidaceae

Bifurcariopsis capensis (Areschoug) Papenfuss 1940: 212-213, fig. 10

Plants yellowish-brown to brown, erect, solitary, to ca. 30 cm in height, with a single conical, grooved, woody holdfast from which a system of repeatedly bifurcate terete branches arises. Erect primary lateral branches also arise directly from the holdfast without the formation of a specialized condensed main axis. Primary branches also woody in texture with the primary laterals up to 6 mm in diameter and each order of branches successively thinner. Branching pattern monopodial and triradial. Structure parenchymatous; medulla of elongated axial cells (filaments) 40 -50 µm in diameter in cross section; cortex of many layers of smaller cells 20-30 µm long in cross section.

Life history with single macroscopic diploid phase in which gametes are produced by meiosis in specialized receptacles. Receptacles formed by slight thickening of ultimate branchlets (from ca. 2 mm to ca. 3 mm in diameter) with fertile portions often more than 10 cm long, containing numerous conceptacles. Conceptacles bisexual; 4 eggs produced per oogonium; antheridia clustered terminally on long unbranched filaments.

Collections, ecology and regional distribution

Found in the lower eulittoral, shallow sublittoral and rock pools from Groen River on the west coast to Cape Infanta (6-24). Probably perennial, dying back to main axes in winter (Stegenga et al. 1997).

World distribution: Monospecific genus endemic to South Africa.

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

Note: Previously regarded as belonging to the family Cystoseiraceae (Jensen 1974), this monospecific genus was placed in its own family by Cho et al. (2006), in their molecular study of representatives of all families in the Fucales.

Bifurcariopsis capensis, False Bay.

Bifurcariopsis capensis, cross section through receptacle showing two conceptacles.

 Bifurcariopsis capensis, cross section showing detail of a conceptacle with oogonia and filamentous antheridiophores.

Bifurcariopsis capensis, XS. 1. Habit of fertile thallus. 2. Detail of cross section. Reproduced from Stegenga et al. (1997).

Order Fucales

Family Sargassaceae

Brassicophycus brassicaeformis (Kützing) Draisma, Ballesteros, F.Rousseau & T.Thibaut 2010: 1339, 1340

Plants yellowish-brown, comprising stands of uprights arising from mats of rhizomatous, intertwined holdfasts. Holdfast a spreading rhizome made up of terete to slightly flattened haptera ca. 2-3 mm in diameter coalescing to form mats up to several metres across. Numerous terete upright axes produced, ca. 3-4 mm in diameter and up to 50 cm long when mature, branching bilaterally and alternately and producing several branches on each side from distal part of upright. Branches become modified into swollen flattened receptacles that contain conceptacles. Constrictions at bases of older branches give impression that receptacles are stalked.

Plants dioecious, with unisexual conceptacles; each upright containing conceptacles of a single sex. Conceptacles in 2 rows along margins of flattened receptacles.

Collections, ecology and regional distribution

Recorded from Sea Point (Cape Town) on the west coast to Struisbaai (15-23). A single record from Algoa Bay is mentioned by (Stegenga et al. 1997), but this needs confirmation. This species dominates areas of rock in the lower eulittoral zone between Cape Agulhas and Cape Point. Holdfast perennial and probably long-lived, uprights produced and become fertile annually. Spread of populations is largely by growth of rhizomatous holdfasts.

World distribution: South African endemic.

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

Note: This entity was previously known as Bifurcaria brassicaeformis (Kützing) Barton, but the molecular study of Draisma et al. (2010) showed that it is sufficiently different from the type species of that genus to require generic recognition.

Brassicophycus brassicaeformis, Struisbaai, young thalli.

Brassicophycus brassicaeformis, typical intertidal thalli.

Brassicophycus brassicaeformis, thalli with fertile uprights.

Brassicophycus brassicaeformis, XS showing conceptacle filled with antheridia.

Brassicophycus brassicaeformis, XS showing cortex and outer medulla.

Brassicophycus brassicaeformis, detail of male reproductive structure.

Brassicophycus brassicaeformis.1. Habit of fertile thallus. 2. Cross section of receptacle with female conceptacles. 3. Detail of cross section, with mucilage cells. Reproduced from Stegenga et al. (1997).

Order Sporochnales

Family Sporochnaceae

Carpomitra costata (Stackhouse) Batters 1902: 46

Plants medium brown, up to 20 (-40) cm tall, comprising robust conical holdfast with felty surface and one to several tough, wiry axes. Axes frequently irregularly branched, compressed, with more-or-less evident midrib. Structure parenchymatous, central medulla of thin-walled cells surrounded by mantle of thick-walled cells especially in region of midrib; cortex of isodiametric cells 5-10 µm in diameter. Meristematic zone at base of terminal tuft of trichothallic filaments.

Unilocular sporangia in subterminal sori surrounding the axis of branches below the terminal tuft of assimilatory filaments; sorus subtended by a cup-shaped vegetative structure. Sporangia borne on several cells of (branched) paraphyses; sporangia elongate ellipsoid, 35-45 x 15 µm ; terminal cells of paraphyses swollen, ovoid or truncate, 15-20 µm in diameter.

Collections, ecology and regional distribution

Recorded from Hout Bay to the Port Shepstone area of Kwazulu-Natal (16-49). A deep water species, found down to around 40 m.

World distribution: widely distributed in tropical and temperate waters (Guiry & Guiry 2012).

Type locality: Fowey, Cornwall, England (Womersley 1987).

Note: our entity was originally described as C. filiformis (Suhr) Papenfuss, with the type specimen from Algoa Bay, but we follow Stegenga et al. (1997) who agreed with Womersley (1987) in considering C. filiformis to belong within the widespread C. costata.

Carpomitra costata, ends of thalli (pressed specimen), ca 0.8-1.2 mm wide.

Carpomitra costata, fruiting body in which unilocular sporangia are produced in sori.

Carpomitra costata, herbarium specimen from the Lizard, England (BOL).

Carpomitra costata. 1. Section of main axis from herbarium material. Reproduced from Stegenga et al. (1997).

Order Sporochnales

Family Sporochnaceae

Carpomitra Kützing

Plants usually up to about 25 cm tall, profusely branched, with slightly to very compressed narrow branches with faint midrib. Holdfast of compressed mass of rhizoids. Growth apical; apices terminated by tuft of trichothallic filaments. Structure pseudoparenchymatous, medulla of elongate axial cells surrounded by cortex of small, pigmented cells. Life history heteromorphic, sporophytes with unilocular sporangia borne laterally on branched paraphyses in conical or cup-shaped apical structures at apices of branches. Gametophytes filamentous, branched, monoecious.

There are 12 described species, of which 3 currently recognized (Guiry & Guiry 2012). Two are currently recorded on the south coast, although one should apparently be placed in a new genus (see later).

Key to species

1a. Branches compressed, with faint midrib; sporangial sori in cup-shaped terminal structures

C. costata

1b. Branches cylindrical, without midrib; sporangia in cylindrical sori borne laterally on branches

C. longicarpa

Order Sporochnales

Family Sporochnaceae

Carpomitra longicarpa Simons 1967: 357-361, fig. 1; pl. 1

Plants medium brown, up to 50 cm tall, comprising hard, callus-like holdfast bearing one to several primary axes; axes terete, up to 1 mm in diameter, alternately to oppositely branched, articulated, terminating in a rounded or flattened sterile knob. Branches thinner than main axis.

Sori borne laterally on branches, club-shaped, cylindrical, up to 6 mm high and 0.6 mm in diameter, with terminal ring-like collar above obvious constriction . Sori comprising inner tissue of elongated sterile cells and outer tissue of radiating sporangiferous filaments bearing unilocular sporangia. Sporangiferous filaments ca. 10 cells and 200 µm long, upper 4-5 cells swollen and pigmented. Sporangia cylindrical, up to 60 µm long x 15 µm wide, attached singly or severally to lower cells of sporangiferous filaments.

Collections, ecology and regional distribution

Recorded from Qologha (just east of Kei Mouth) to Aliwal Shoal, 50 km south of Durban (43-49) Sublittoral, mainly in deeper water (to at least 25 m).

World distribution: South African endemic.

Type locality: Mzamba, Eastern Cape (Silva et al. 1996).

Note: Fundamental differences between this species and other members of the genus suggest that it should probably be placed in another genus (see note in Stegenga et al .1997). BOL 141082 bears a note by AJK Millar, dated 20 January 2004 : 'This represents a new undescribed genus ...'

Carpomitra longicarpa, Qolora, Transkei.

Carpomitra longicarpa, club-shaped sorus with terminal collar.

Carpomitra longicarpa, cross section of vegetative axis, Mzamba (stained slide preparation).

Carpomitra longicarpa, cross section of tip of fertile thallus showing outer layer of radiating filaments bearing unilocular sporangia (Mzamba, stained slide preparation).

Carpomitra longicarpa, cross section of tip of fertile thallus, detail of radiating filaments bearing unilocular sporangia (Mzamba, stained slide preparation).

Ectocarpales

Family Scytosiphonaceae

Chnoospora implexa J.Agardh 1848: 172

Plants brown, comprising entangled branching axes forming a cushion at least a few cm wide. Thalli cylindrical to compressed, 1-2 mm in diameter below, decreasing to 0.2 mm or less at the tips. Branching irregular becoming dichotomous near the apices; branches sometimes adhering to each other. Structure solid; medulla of large colourless cells surrounded by cortex of small pigmented cells. Reproductive structures not seen in our material.

Collections, ecology and regional distribution

Apparently rare on our coast, and probably in intertidal pools and some estuaries. On the south coast only recorded Mbotyi in northern Transkei (47) but there is one specimen in BOL of apparently the same species from Island Rock (near Mabibi) in northern KZN, indicating a possible distribution eastwards through Kwazulu-Natal.

World distribution: recorded from scattered tropical localities more-or-less worldwide, including Tanzania and Kenya in East Africa.

Type locality: Sinai Peninsula, Egypt (Agardh 1848).

 Note: In Tanzania this species is reported to grow up to 30 cm long and in cushions up to 15 cm wide (Jaasund 1976). C. implexa from Japan was shown to have a heteromorphic life history in culture, the dioecious gametophytes alternating with a discoid sporophyte generation (Kogame 2001).

Chnoospora implexa, herbarium specimen from Mbotyi.

Chnoospora implexa, herbarium specimen from Mbotyi showing branching: main axes ca 1 mm wide.

Chnoospora implexa, xs of Mbotyi specimen showing inner layer of colourless medullary and outer layer of pigmented cortical cells (stained slide).

Ectocarpales

Family Scytosiphonaceae

Chnoospora J. Agardh

Thalli irregularly to dichotomously branched; structure solid, comprising medulla of large cells and cortex of small pigmented cells; hair tufts common.

Four species are currently recognized (Guiry & Guiry 2011); two are found on the south coast.

Key to species

1a. Thallus soft, forming tangled cushion

C. implexa

1b. Thallus firm, of tufts of uprights

C. minima

Ectocarpales

Family Scytosiphonaceae

Chnoospora minima (Hering) Papenfuss 1956: 69

Plants brown to yellow-brown, up to about 8 cm tall, comprising tufts of branched uprights attached by rhizoidal holdfast; erect axes terete to compressed, 1-2 mm wide, 3-6 times dichotomously to irregularly branched at angles of 30-50o, apices pointed, often forked. Structure solid, with medulla of large colourless cells surrounded by cortex of small pigmented cells; hair tufts emerging through cortex, scattered over thallus. Plurilocular sporangia up to about 55 µm long, in sori, often associated with hair tufts.

Collections, ecology and regional distribution

Epilithic, found in wave-exposed sites in the lower eulittoral/eulittoral fringe. Recorded from Dwesa to northern KwaZulu-Natal (44-58).

World distribution: Widespread in tropical and warm-temperate waters; in southern Africa also recorded in Mozambique (Guiry & Guiry 2011).

Type locality: Port Natal (Durban), South Africa (Tronchin & De Clerck 2005).

Chnoospora minima, whole thallus.

Chnoospora minima, xs of thallus showing plurilocular sporangia (Mkambati specimens, stained slide).

Chnoospora minima, xs of edge of thallus showing tuft of phaeophycean hairs.

Order Ectocarpales

Family Adenocystaceae

Chordariopsis capensis (C.Agardh) Kylin 1940: 54, fig. 30

Plants brown to yellow-brown, branched and stringy, up to 40 cm long, comprising several erect thalli arising from a crustose base. Thallus comprising a number of terete indeterminate main axes, generally less than 1 mm in diameter, from which arise a profusion of terete, determinate secondary branches of varying lengths, irregularly inserted at wide angles. Laterals often unbranched, but may bear profuse, often short, branches. Structure of pigmented cortex of cells ca. 12-14 µm long x 5-8 µm in diameter, organised in radiating filaments of 3-5 cells (ca. 40 µm ) deep, grading below into an unpigmented medulla of a very compact pseudoparenchyma, with roundish cells ca. 25-30 µm in cross-sectional diameter; longitudinally elongated, older axes with a schizogenic cavity. In corss-section, medullary cells in a spiral pattern. Hairs absent in our material.

Unilocular sporangia embedded in paraphyses, in sori 50-60 µm deep; cylindroconical to ovate, ca. 25-50 µm long and 10 µm maximum) in diameter; paraphyses clavate, loosely arranged, unicellular (occasionally 2-celled), 25-40 µm long.

Collections, ecology and regional distribution

Abundant in intertidal rock-pools, particularly in the upper eulittoral zone. Recorded along the entire west coast to at least the Tsitsikamma region (1-32).

World distribution: Also recorded from Namibia and New Zealand, Macquarie Island, and Antarctica (Guiry & Guiry 2011).

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

Chordariopsis capensis, attached to small mussel shells, Kommetjie, Western Cape.

Chordariopsis capensis, xs showing filamentous cortex and parenchymatous medulla.

Chordariopsis capensis, xs of crustose base attached to piece of mussel shell.

Chordariopsis capensis. 1. Habit. 2. Cross section. 3. Section of crustose base on mussel shell. 4. Unilocular sporangia in cross section of thallus. Drawings from Stegenga et al. (1997).

Order Ectocarpales

Family Scytosiphonaceae

Colpomenia sinuosa (Mertens ex Roth) Derbès & Solier in Castagne 1851: 95

Plants yellowish-brown, hollow, convoluted-globose, several to 10 cm in diameter, attached by rhizoids from broad base. Structure of ca. 4 layers of large colourless medullary cells becoming smaller towards the cortex, surrounded by cortex of 2-3 layers of small isodiametric cells, with surface cells ca. 7 µm in diameter; bundles of phaeophycean hairs ( ca. 8-9 µm in diameter) emerging through cortex from the medulla.

Plurilocular sporangia in raised sori, covered by cuticular membrane and often associated with hair bundles. Plurilocular sporangia uniseriate with ca. 6 locules ca. 20 µm long x 4 µm wide, with occasional unicellular paraphyses. Unilocular sporangia unknown.

Collections, ecology and regional distribution

Recorded along the whole South African coast (1-58), but see note 1 below. Found in rock pools and in the lower eulittoral zone, often epiphytic on larger algae.

Worldwide distribution: worldwide in tropical and temperate waters (Guiry & Guiry 2011).

Type locality: near Cádiz, Spain (Guiry & Guiry 2011).

Notes: 1. A second species, Colpomenia claytonii S.M.Boo, K.M.Lee, G.Y.Cho et W.Nelson, is recorded from Seaforth Beach in False Bay, Western Cape (Boo et al. 2011), and may be more widely distributed in South Africa. Unlike C. sinuosa, this species has a single layer of angular cortical cells (rather than 1-2 layers of cuboidal cells), and phaeophycean hairs that arise from the cortex (rather than the sub-cortical medulla). Mature plurilocular sporangia in C. claytonii have 6-8 locules compared to 8-12 locules in C. sinuosa.

2. Some specimens of C. sinuosa may appear superficially similar to Leathesia marina, but the latter species has a better-developed medulla and is spongy rather than completely hollow. Clusters of small Colpomenia plants may resemble Iyengaria stellata, but the latter species has solid thalli (at least in younger plants) and thicker walls - of at least 10 cell layers (Stegenga et al. 1997).

Colpomenia sinuosa, Haga Haga tidal pool, under water.

Colpomenia sinuosa, mid eulittoral zone, Struis Bay.

Colpomenia sinuosa, xs through cortex and outer medulla, Nature's Valley material.

Colpomenia sinuosa. 1. Habit. 2. Cross section of sterile specimen. 3. Cross section with plurilocular sporangia, paraphyses and hair bundle. Drawings from Stegenga et al. (1997).

Order Cutleriales

Family Cutleriaceae

Cutleria multifida (Turner) Greville 1830: xliv, 60, pl. 10

Gametophytic plant never recorded on south coast (see note); pale brown, erect, up to about 30 cm tall, strap-shaped, one to several blades arising from small rhizoidal holdfast; blades branched, up to about 5mm wide; growth from base of tuft of trichothallic hairs.

'Aglaozonia' phase (sporophyte of Cutleria)

Plants prostrate, loosely attached to substratum by rhizoids, medium-brown to reddish-brown, up to more than 5 cm in diameter, comprising fan-shaped to rounded, branched lobes, sometimes with concentric growth rings. Growth from line of marginal apical cells; thallus ca. 130 µm thick, generally 5-6 cells deep, comprising upper cortex of 2 regular rows of small pigmented cells (outer row quadrate, ca. 6-7 µm in diameter, inner row variable-shaped, 9-16 µm in diameter), an inner medulla of 3 rows of larger irregular polygonal, colourless cells (ca. 25-35 µm in diameter) and a lower cortex of a single row of irregular quadrate to elongated cells, 8-13 µm deep and 10-30 µm long. Attaching rhizoids ca. 10 µm wide, usually comprising 2 elongate cells and a multicellular digitate hapteron. Phaeophycean hairs in dense bundles on dorsal surface, replacing squarish patches of surface cells. Reproductive structures not observed in our material: reported to comprise surface sori of unilocular sporangia.

Collections, ecology and regional distribution

Recorded from Table Bay to Bird Island (Algoa Bay) (15-38). Known only from the shallow subtidal zone, where it often overgrows crustose corallines.

World distribution: Widely distributed in temperate and some tropical localities (Guiry & Guiry 2012).

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

Note: The Aglaozonia phase of this species is fairly common from False Bay to Algoa Bay, and may be distributed further eastward than current records indicate, because of the lack of collections in the subtidal zone. The only record of the gametophyte of C. multifida from South Africa was the discovery of a single population in a new yacht basin in Table Bay in November 2000. That population subsequently disappeared, and we assume that it was introduced via a yacht, but that conditions in the basin later proved unfavourable for its survival. DNA analysis of the Aglaozonia phase (from False Bay) showed that it is conspecific with European Cutleria multifida (O. De Clerck, pers. comm.)

Cutleria multifida, gametophytes, yacht basin behind Cape Grace Hotel, Cape Town Harbour, collected 17 November 2000, RJ Anderson (BOL 141194). Gametophytes not seen on south coast.

Aglaozonia phase of Cutleria multifida, False Bay.

Aglaozonia phase of Cutleria multifida, False Bay, XS, showing rhizoids and general structure (Bird Island, Algoa Bay, stained slide preparation).

Aglaozonia phase of Cutleria multifida, surface view showing dark margin of apical cells.

Aglaozonia phase of Cutleria multifida. 1. Habit. 2. Cross section. 3. Thallus margin in surface view. Reproduced from Stegenga et al. (1997).

Order Fucales

Family Sargassaceae

Cystophora fibrosa Simons 1970: 1, figs. 1, 2

Plants dark brown to yellowish-brown, branched, up to 50 cm (-1 m) high; fibrous in texture. Holdfast irregularly conical, up to 6 mm in diameter, bearing a single primary axis. Thallus comprising two distinct branching systems; primary system with 1-3 orders, flexuous, distichous, giving rise to a secondary system of branches producing fascicles of narrower branches by bifurcation in a radial, alternate fashion.

Receptacles formed from ultimate branches that become slightly distorted with numerous swellings and constrictions at intervals. Vesicles absent. Receptacles containing 2-3 rows of bisexual conceptacles; conceptacles sub-spherical, ca. 0.5 mm in diameter with 1 egg per oogonium. See Simons (1970) for further details of reproductive anatomy.

Collections, ecology and regional distribution

Recorded in a very restricted area from Die Walle, just west of Cape Agulhas, to Koppie Alleen, De Hoop (22-24) although Stegenga et al. (1997) reported that a few plants were found at Platboom on the Cape Peninsula.

World distribution: Also reported from the Canary Islands and Mauritania (Guiry & Guiry 2012).

Type locality: Die Walle, South Africa (Simons 1970).

Note: This species may be better placed in Cystoseira, on morphological grounds (Womersley 1987) and in terms of its chemistry (Laird & van Altena, 2006).

Cystophora fibrosa, Arniston, showing fertile receptacles.

Cystophora fibrosa, De Hoop rock pool.

Cystophora fibrosa, XS of receptacles, showing three conceptacles.

Cystophora fibrosa, XS of a receptacle, showing oogonia and antheridiophores.

Cystophora fibrosa, habit of fertile plant. Reproduced from Stegenga et al. (1997).

Order Dictyotales

Family Dictyotaceae

Dictyopteris J. V. Lamouroux

Plants prostrate or erect, blades flat to ligulate, with conspicuous midrib, branching subdichotomous. Blades distomatic to multi-layered, depending on species. Attachment by matted rhizoidal holdfast. Reproductive organs embedded in or on surface of blades. Members of the genus are widely distributed in temperate to tropical seas worldwide and 36 species are currently recognized (Guiry & Guiry 2012). Three species are currently recognized on the south coast. Of these, only D. ligulata is recorded from the west coast (Stegenga et al. 1997).

Key to species

1a. Blade margins with regular small teeth, side veins arising from midrib

D. serrata

1b. Blade margins entire or lacerate, without teeth, side veins absent

2

2a. Blades with hair tufts and sori forming conspicuous horizontal rows of light-coloured spots

D. macrocarpa

2b. Hair tufts in oblique lines from midrib towards margins, not very conspicuous; sori in lines parallel to and on both sides of midrib

D. ligulata

Dictyotales

Dictyotaceae

Dictyopteris ligulata (Suhr) O.C.Schmidt 1938: 219

Plants brown to yellowish-brown, up to 30 cm tall, blades strap-shaped, subdichotomously branched, with lighter coloured midrib and smooth margins; holdfast a mat of rhizoids. Blades 1-1.5 cm wide throughout, midrib ca. 3 mm wide; blade wings ca. 200 µm thick, midrib ca. 400 µm thick. Hairs in tufts, forming obliquely-oriented lines from midrib towards margins. Cortex a single layer of densely pigmented cells 15-18 µm deep x 10-13 µm wide. Medulla up to 6 cells deep in outer wings of blade, up to 14 cells deep in midrib. Medullary cells in obvious rows, variable in shape from polygonal to elongated, smaller near thallus edge. Sporangia ca. 100 µm in diameter, dividing tetrahedrally when mature; in sori on both sides of midrib, almost completely embedded in cortex. Gametangia not seen.

Collections, ecology and regional distribution

Common in the lower eulittoral and shallow subtidal zones. Recorded from the Cape Agulhas region to Black Rock in northern Kwazulu-Natal (22-58).

World distribution: southern African endemic.

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

Note: Stegenga et al. (1997) considered that D. ligulata was the correct name for the species known as D. longifolia (Papenfuss, nom. inval.). Nevertheless there may be more species of Dictyopteris present on the South Coast and this group needs re-investigation in South Africa.

Dictyopteris ligulata, Port Alfred, showing characteristic markings.

Dictyopteris ligulata (herbarium specimen, Dome Bluff, Transkei).

Order Dictyotales

Family Dictyotaceae

Dictyopteris macrocarpa (Areschoug) O.C.Schmidt 1938: 219

Plants dark to yellowish-brown, up to 35 cm tall, comprising several branched, strap–shaped blades with distinct, lighter-coloured midrib; attached by holdfast of matted rhizoids. Blades 12-22 mm wide, dichotomously branched, distally with axes arising from midrib; margins smooth to lacerate; blade surface smooth, becoming rugose in fertile areas; lines of hair tufts oriented perpendicular to midrib creating lighter-coloured striations across blades. Blade wings up to 170 µm thick, comprising 2 layers of cortical cells and 2-3 layers of medullary cells; midrib up to 20 cell layers thick. Sporangia associated with hair tufts, in oval sori, not embedded in cortex. Gametangia not seen. Further details in Tronchin & De Clerck (2005).

Collections and regional distribution

Epilithic in rock pools, and lower eulittoral to subtidal zones to 30 m depth. Recorded from Port Alfred to northern Kwazulu-Natal (39-58).

World distribution: Also recorded from Mozambique and Oman (Guiry & Guiry 2012).

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

Note: We have specimens from De Hoop and Tsitsikamma that look very similar to D. macrocarpa, but the blades are too thin (too few cell layers). They and some unnamed specimens in BOL do not completely fit the descriptions of either D ligulata or D. macrocarpa (also see notes in Silva et al. 1996). This group in South Africa clearly needs molecular study.

Dictyopteris macrocarpa, with characterisits lines of hairs on blade (KZN specimen).

Dictyopteris macrocarpa, Port Alfred specimen (BOL).

Dictyopteris macrocarpa, Kosi Bay, KZN (BOL).

Dictyopteris macrocarpa, Kosi Bay, KZN (BOL), showing horizontal lines of sori and hairs.

Order Dictyotales

Family Dictyotaceae

Dictyopteris serrata (Areschoug) Hoyt 1920: 460

Plants yellowish-brown, up to about 30 cm tall, sparely dichotomously branched, blades 1.3-3.0 cm wide, midrib conspicuous and lighter coloured, margins entire and with distinctive dentation. Attachment by matted rhizoidal holdfast. Blades ligulate, conspicuous nerves running out from midrib obliquely towards margins.Sporangia in small, inconspicuous sori in lines parallel to veins. Oogonia not seen in our material: reported by Hoyt (1920) to be scattered over both surfaces of blades, mainly near midrib and margins. See also description in Tronchin & De Clerck (2005).

Collections ecology and regional distribution

Recorded from Hluleka to northern Kwazulu-Natal (45-58). Found from the sublittoral fringe to subtidal zone.

World distribution: Also recorded from Mozambique, Mauritius, Kenya, Reunion, Australia and North Carolina, USA (Hoyt 1920; Guiry & Guiry 2012).

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

Note: there are several specimens from Port Alfred and other areas (BOL) labelled D. serrata but lacking marginal dentition. These appear more similar to D. macrocarpa, but it is clear that these entitities need further study (see note on D. macrocarpa).

Dictyopteris serrata, 10m depth, northern KwaZulu-Natal.

Dictyopteris serrata, at 10 m depth, northern KwaZulu-Natal, detail.

Order Dictyotales

Family Dictyotaceae

Dictyota dichotoma (Hudson) J.V.Lamouroux 1809: 42

Plants mid-brown to yellow-brown, morphologically rather variable (we include the former D. dichotoma var intricata (C. Agardh) Greville in this entity.- see note); from a few to 6 cm tall, fairly regularly dichotomously branched in one plane with up to 10 orders of branches, axes between 1 and 5 mm wide; branch apices rounded; branches often contorted in narrower specimens; some plants with repent basal axes. Axes 100 – 140 µm thick, comprising single layer of large medullary cells inside a single-layered cortex. In cross section medullary cells 75-80 µm high, cortical cells 10-13 µm high.

Collections, ecology and regional distribution

Reported in Langebaan Lagoon then from the west side of the Cape Peninsula to KwaZulu-Natal (Stegenga et al. 1997), but eastern limits uncertain (13, 16-48?). Found in the shallow sublittoral zone and in rock pools in the lower eulittoral.

World distribution: Reported to be widespread on temperate and tropical coasts (MD Guiry in Guiry & Guiry 2016), but molecular studies are required worldwide. Although De Clerck (2003) considered that this species may be restricted to the north-east Atlantic Ocean and Mediterranean Sea, recent molecular evidence confirms its occurrence in South Africa (O. De Clerck, pers, comm).

Type locality: Walney Island, Lancashire, England (Silva et al. 1996).

Note: Tronholm et al (2010) reported that European D. dichotoma var intricata could not be genetically distinguished from D. dichotoma. Furthermore, our specimens show a range of forms that encompass both entities as morphologically delimited. We therefore treat all of them as D. dichotoma.

Dictyota dichotoma, pressed specimen, Gansbaai (D 204, identity confirmed molecularly: O De Clerck, pers comm.).

Dictyota dichotoma, repent form, Noetsie, De Hoop. Axes up to 2.5 mm wide (specimen D 950 Noetsie, De Hoop, identity confirmed molecularly: O De Clerck, pers comm.).

Dictyota dichotoma, cross section (specimen D 950 Noetsie, De Hoop) showing large medullary and small cortical cells.

Dictyota dichotoma. 1. Habit of narrow form (previously called D. dichotoma var intricata). 2. Habit of wider form, sporangiferous thallus. Reproduced from Stegenga et al. (1997).

Dictyota dichotoma. 1. Thallus apex. 2. Cross section. Reproduced from Stegenga et al. (1997).

Order Dictyotales

Family Dictyotaceae

Dictyota Lamouroux

Thallus flattened, blades (usually erect) branching (sub-) dichotomously in one plane. Growth by means of a single apical cell. Phaeophycean hairs in scattered tufts. Thallus three cells thick, comprising a single layer of large medullary cells with a single layer of smaller pigmented cortical cells on either side; in some species cell layers may be duplicated in some individuals.

Gametophytes dioecious, oogamous, with reproductive structures exserted; oogonia and antheridia in scattered sori, the latter surrounded by a margin of sterile paraphyses. Sporophytes producing scattered or grouped tetrasporangia, each with 4 non-motile meiospores; sporangia often found with undivided contents.

For further details of most South African species, see Tronchin & De Clerck (2005) and Stegenga et al. (1997). Worldwide, 91 species are currently recognised (Guiry & Guiry 2016), of which 4 are recorded from the South African south coast, including one that appears to be undescribed.

Note: The entity previously known as Dictyota suhrii, (now Rugulopteryx suhrii )can be easily distinguished from south coast Dictyota species by the teeth along its margins.

Key to south coast species

1a. Branching with a very unequal development of dichotomies; plants therefore appearing to have a flexuous main axis and alternating laterals

D. liturata

1b. Branching with (almost) equal development of dichotomies: plants therefore without a main axis

2

2a. Plants robust, up to 20 (-35) cm tall, blades to 1 cm wide or wider, iridescent bluish in situ or when fresh

D. naevosa

2b. Plants rather delicate, 1 to 6 (-10) cm tall, blades rarely more than 4 mm wide

3

3a. Plants small (10-20 mm), erect but often curving downward toward substratum, in situ often with bright green edges; axes 0.5 – 2 mm wide, ca. 80 µm thick

Dictyota sp1

3b. Thalli erect, up to ca 6 cm tall, a few to 5 mm wide, 100-140 µm thick, from neatly dichotomous (wider forms) to somewhat contorted (narrower forms)

D. dichotoma

Order Dictyotales

Family Dictyotaceae

Dictyota liturata J. Agardh 1848: 95

Thallus up to ca 20 cm tall, brown and non-iridescent; one to several uprights arising from a single rhizoidal attachment. While Tronchin & De Clerck describe this species as 'completely erect', Stegenga et al. (1997) note 'a comparatively extensive prostrate foliose part'. Branching often appearing alternate because of uneven development of dichotomies; branches 4-7 mm wide, width similar throughout thallus but tapering slightly towards apices; apices rounded to truncate; margins smooth. Single layer of medullary cells, cortex usually single layered, but sometimes double-layered near edges. Medullary cells 60-130 µm long, 35-80 µm wide, 13-20 µm high; cortical cells approximately 10-22 µm wide, 13-18 µm high. Hair tufts common, as bundles of hairs in gaps in cortical cells, circular in surface view, ca. 150 µm in diameter.

Tetrasporangia frequent on both surfaces, clavate to sub-spherical, to 130 µm long, dividing tetrahedrally when mature, arranged in an irregular soral network. Oogonial sori ovoid, distributed over thallus surface, on average ca. 415 µm long x 270 µm wide. Antheridial sori not seen in our material, but described by Tronchin & De Clerck, (2005) as forming irregular patches surrounded by 2-3 rows of hyaline paraphyses. 

Description adapted from Tronchin & De Clerck, (2005). Note that their description differs in some respects from that in Stegenga et al. (1997). 

Collections, ecology and regional distribution

Recorded from Kommetjie to Sodwana Bay. Although Stegenga et al. (1997) quoted an eastern limit of Still Bay, recent DNA sequencing indicates a wider distribution along the whole south coast to northern KZN (pers. Comm. O. De Clerck) (17-58). Found in rock pools and the sublittoral zone down to at least 30 m depth (Tronchin & De Clerck, (2005).

World distribution: also recorded from certain Atlantic islands (Azores, Canary islands, madeira Salvage Islands, Tristan da Cunha) and Madagascar (references in M.D. Guiry in Guiry & Guiry 2016).

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

Dictyota liturata, Aliwal shoal, 18 m depth (BOL).

Dictyota liturata, intertidal rock pool, Palm Beach, KZN (BOL).

Dictyota liturata, Millers Point, False Bay, 3m depth (BOL).

Dictyota liturata, habit (reproduced from Stegenga et al. (1997). Note prostrate axes at base.

Dictyota liturata, . 1and 2 - Cross sections at thallus edge (note two-layered cortex in Fig.3). 3 Unilocular sporangia. Reproduced from Stegenga et al. (1997).

Dictyota liturata, Bordjiesrif, False Bay, showing extensive prostrate parts, as noted in the description of this species according to Stegenga et al. (1997). [Specimen D 2184)

Order Dictyotales

Family Dictyotaceae

Dictyota naevosa (Suhr) Montagne 1840: 145

Thalli erect, up to about 35 cm tall, pale brown to yellowish-brown with blue iridescence. Thallus by a matted rhizoidal holdfast. Branches to about 1 cm wide, branching sub-dichotomous, in up to 10 orders; final branches up to 10 cm long, apices rounded. Internal structure usually of single layer of medullary cells covered on each surface by single layer of cortical cells, but sometimes all layers are duplicated. Cortical cells ca. 25 µm deep and 10-15 µm wide; medullary cells ca. 115 µm long, 70 µm wide and 130-160 µm high. Tetrasporangial sori on both frond surfaces, elongate-ovoid, up to about 1.5 mm long, often with central hair tufts; tetrasporangia to about 80 µm in diameter. Oogonial sori elongate-ovoid sori, on average about 400x300 µm , distributed evenly over blade surface, without hair tufts; oogonia clavate, about 90x40 µm . Antheridial sori uniformly distributed over blade surface and often merging into patches, associated with hair tufts; surrounded by 3-6 rows of unicellular clear paraphyses. Further details in Tronchin & De Clerck (2005) and Stegenga et al. (1997).

Collections, ecology and regional distribution

Recorded from False Bay around the whole south coast and as far east as Mission Rocks in northern KwaZulu-Natal (17 -57). Common, epiphytic and epilithic in rock pools, the sublittoral fringe and shallow sublittoral on wave-exposed coasts; often in sand-affected gulleys.

World distribution: also recorded from the Canary Islands, Senegal, Japan and South and Western Australia (references in Guiry & Guiry 2016).

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

Dictyota naevosa, De Hoop. Note bluish iridescence.

Dictyota naevosa, section though part of an oogonial sorus showing oogonia, cortex and part of medullary cells.

Dictyota naevosa, surface view of thallus showing oogonial sori (dark patches).

Dictyota naevosa, s. 1 Habit. 2 Thallus apex. 3 Oogonia in cross section of thallus. Reproduced from Stegenga et al. (1997).

Order Dictyotales

Family Dictyotaceae

Dictyota sp1

Plants olive-brown, forming tufts or turfs ca. 10 mm high on various substrata. Thalli sometimes with distinctive bright green edges in situ (these disappear in pressed or preserved material). Erect axes up to 20 (-25) mm long, arising from a narrow base attached by rhizoidal holdfast, usually curving towards the substratum distally. Thalli often with basal repent branches. Branching dichotomous/subdichotomous; apices blunt to rounded (obtuse). Axes usually up to 1.5-2 mm wide, more regularly branched in up to 3 orders; many plants also with some narrower axes (to 0.5-0.8 mm wide) that are more irregularly branched in up to 4 orders. Axes sometimes with small marginal branchlets. Main erect axes about 110 µm thick near base, 60-80 µm thick near apices. Anatomy typical of Dictyota, with a single layer of large medullary cells (in cross section 40-90 µm high, depending on thallus region) and a layer of small pigmented cortical cells on each side (about 15 µm high in cross section). Reproductive structures not seen.

A current DNA study of Dictyota from many worldwide localities, including many in southern Africa, shows this to be a distinct species (Olivier De Clerck, pers. comm), although it was often confused with “D. dichotoma”, which is, however, molecularly and morphologically different.

Collections, ecology and regional distribution

Recorded from False Bay to Isipingo, Kwazulu-Natal. A common but not abundant species in wave-washed areas on various substrata (rock, Pyura tests, Gunnarea) in the lower eulittoral , shallow sublittoral, and in pools. It is often but not always marked by distinctive, bright green edges.

Note: In the current study by De Clerck this species is provisionally denoted as Dictyota sp_7.

Dictyota sp 1, showing bright green edges (Arniston).

Dictyota sp 1, showing bright green edges; growing on a limpet (hidden), on a crust of Zeacarpa leiomorpha (Natures Valley).

Dictyota sp 1, cross section at edge of blade, near blade tip, showing large medullary and small cortical cells.

Dictyota sp 1, showing range of frond shapes

Order Laminariales

Family Lessoniaceae

Ecklonia Hornemann

Life history heteromorphic; macroscopic (large) sporophyte alternating with microscopic filamentous gametophyte. Sporophyte thallus comprising holdfast, stipe and blades. Holdfast of branched terete haptera. Stipe solid or hollow, usually terete. Primary blade terminal on stipe, usually smooth; secondary blades arising from margins of primary blade, smooth, spiny or rugose. Sori of plurilocular sporangia usually confined to secondary blades.

Ecklonia occurs in most warm temperate seas, particularly southern Africa, Australia, New Zealand and the north-western Pacific, and is often an ecological dominant. It is rare in the north Atlantic and absent from the eastern Pacific (Bolton & Anderson 1994). Nine species are recognised at present (M.D. Guiry in Guiry & Guiry 2014), of which two are recorded from the south coast of South Africa.

Key to the species

1a. Stipes hollow, (usually) long (up to 8 m), blade surfaces always smooth

E. maxima

1b. Stipes solid, short (a few to ca 40 cm long), blade surfaces often corrugated and/or with spines

E. radiata

Order Laminariales

Family Lessoniaceae

Ecklonia maxima (Osbeck) Papenfuss 1940: 7

Sporophyte up to about 4 m tall (to at least 10 m on west coast), comprising well-developed holdfast of branched haptera, elongated cylindrical stipe up to 1.5 m long (to 10 m on west coast) with gas-filled bulb near top, and short triangular primary blade bearing marginal secondary blades. Blades smooth, margins lightly dentate; young primary blade strap-shaped, up to 1 m long, flexuous, becoming shorter, rigid and triangular in mature specimens. Secondary blades arising bilaterally, sometimes bearing some tertiary blades in older plants. Mucilage ducts present in stipes and blades. Plurilocular sporangia in raised sori in patches or strips near centre of secondary blades. Gametophytes filamentous, microscopic.

Collections, ecology and regional distribution

A dominant west coast species that forms extensive kelp beds from just north of Luderitz in Namibia to Papenkuilsfontein about 10 km west of Cape Agulhas, and very recently recorded also from Koppie Alleen, De Hoop, indicating a recent range extension of some 70 km (Bolton et al. 2012). The hollow stipe and gas-filled bulb enable detached sporophytes to float long distances: large specimens have been cast ashore as far east as Port Alfred. Drift plants have been seen as far as Tristan da Cunha (Stegenga et al. 1997).

World distribution

Also recorded from St Helena, The Falklands, St. Paul and the Auckland Islands (M.D. Guiry in Guiry & Guiry 2014), although Papenfuss (1942b) considered most of these old records unlikely.

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

Note: The only attached Ecklonia maxima known to occur on the south coast is the one small population that has appeared relatively recently at De Hoop (see Bolton et al. 2012 for further details).

Ecklonia maxima, Koppie Alleen, De Hoop, 2010.

Ecklonia maxima, De Hoop specimen showing the hollow stipe typical of this species.

Ecklonia maxima, cross section through fertile soral area of sporophyte blade (False Bay specimen).

Order Laminariales

Family Lessoniaceae

Ecklonia radiata (C.Agardh) J.Agardh 1848: 146

Sporophytes to 1 m tall, but longer in some deep subtidal specimens. Stipe solid, cylindrical, rather rigid, up to about 50 cm long. Holdfast of branching haptera, robust, conical. Primary blade usually short, secondary blades arising from margins, smooth or spinose and /or rugose. Some populations with elongate primary blades. Sori of unilocular sporangia in patches on primary or secondary blades, apparently mainly on upper surface, but also on sides of spines.

Note: Spinose forms were previously referred to E. biruncinata (Bory) Papenfuss, but the South African specimens are considered to belong to E. radiata (Bolton & Anderson 1994). The temperature tolerances of E. radiata, E. maxima and their hybrid sporophytes were investigated by Bolton & Anderson (1987).

Collections, ecology and regional distribution

Locally common in the sublittoral fringe and rock pools at various locations between De Hoop and Port Edward, but apparently absent from many others. Deeper subtidal populations have been recorded in False Bay (10-30m), on the Agulhas Bank off De Hoop/Agulhas (35m depth) and as far east as off Sodwana Bay, northern Kwazulu-Natal (to 60 m) (Tronchin & De Clerck, 2005).

World distribution: Australia, New Zealand, Canary and Cape Verde Islands, Oman,

Madagascar, Senegal (M.D. Guiry in Guiry & Guiry 2014).

Type locality: 'New Holland' (Australia) (Womersley 1987).

Ecklonia radiata, Double Mouth, near Morgan Bay.

Ecklonia radiata, Double Mouth, near Morgan Bay, intertidal population of young plants with long primary blades.

Order Ectocarpales

Family Ectocarpaceae

Ectocarpus fasciculatus Harvey 1841: 40

Plants brown, up to 1-3 cm long, epiphytic on larger seaweeds, comprising tightly-packed tufts of uniseriate filaments arising from a mass of irregularly branched basal filaments. Erect axes profusely branched with primary filaments of barrel-shaped cells reported in west coast specimens to be up to ca. 50 µm wide x 80 µm long, but smaller in some of our south coast specimens (12.5-20 µm wide). Secondary branches narrower, ca. 10 µm wide, arising in fascicles mainly from distal half of primary axes; commonly a third order of branches produced adaxially. All orders of branching tapering gradually. Growth diffuse : no clear meristematic zone. Cells with several elongate plastids each with several pyrenoids. Plurilocular sporangia ca. 80 x 20 µm , usually borne adaxially in series on branches, pedicellate, cylindro-conical. Unilocular sporangia not seen.

Collections, ecology and regional distribution

Epiphytic on various large seaweeds (e.g. Anthophycus longifolius, Ecklonia radiata). Recorded from the Orange River to Mbotyi (1-47).

World distribution: Widespread in temperate seas (Guiry & Guiry 2011).

Syntype localities: Mangan's Bay, Co. Waterford, Ireland: Miss Ball; Strangford Lough, Northern Ireland: On Zostera: W. Thompson; Torquay: Mrs Griffiths (Harvey 1841: 40). According to Guiry & Guiry (2011) a type has not been selected from the syntypes.

Ectocarpus fasciculatus.

Ectocarpus fasciculatus.

Ectocarpus fasciculatus, detail of plurilocular sporangia.

Ectocarpus fasciculatus, detail of thallus with plurilocular sporangia (reproduced from Stegenga et al. 1997).

Order Ectocarpales

Family Ectocarpaceae

Ectocarpus Lyngbye

Plants comprising uniseriate branched filaments; branching generally profuse; each cell containing one or more ribbon-shaped, parietal plastids. Growth diffuse, intercalary. Plurilocular sporangia terminal or pedicellate on branches, scattered; unilocular sporangia rarely seen, ovoid to sub-spherical. A widely-distributed genus with 417 described species, of which 71 are accepted currently (Guiry & Guiry 2011). Two species are definitely recorded on the south coast. A doubtful third record (E. rallsiae) comes from Hluleka (Bolton & Stegenga 1987), but is not described here as no material can be found and the record cannot be confirmed.

Key to species

1. Sporangia in adaxial series on proximal parts of thallus

E. fasciculatus

2. Sporangia scattered on thallus

E. siliculosus

Order Ectocarpales

Family Ectocarpaceae

Ectocarpus siliculosus (Dillwyn) Lyngbye 1819: 131, pl. 43B, C

Plants brown, usually 1-2 cm long but rarely up to 20 cm long, tufted, comprising mass of freely-branched axes; main axis indistinguishable. Filaments up to 30 µm wide, tapering towards apices, sometimes ending in pseudohairs. Cells 0.5 – 2.0 times longer than broad but longer in pseudohairs. Plurilocular sporangia scattered, pedicellate or terminal on longer branches , conical, very variable in length, up to 120 µm long or longer and 20-30 µm in diameter. Unilocular sporangia not observed.

Collections, ecology and regional distribution

Epilithic or epiphytic on various algae and on estuarine higher plants in eulittoral/shallow sublittoral zones, often abundant and particularly large in brackish habitats. Recorded from Port Nolloth to the East London area (1-41).

World distribution: recorded almost everywhere, from the Antarctic through the tropics to the Arctic (Guiry & Guiry 2014).

Syntype localities: Cromer in Norfolk and Hastings in East Sussex, England (Dillwyn 1809 in Guiry, M.D. & Guiry, G.M. 2014).

Notes: 1. This common and ubiquitous species includes numerous synonyms (Guiry & Guiry 2014). 2. South African material seems to show far less variability/variation than the European species, in which, for instance, plurilocular sporangia may be up to 700 µm long). Stegenga et al. (1997) described but did not illustrate South African west coast material of this species.

Ectocarpus siliculosus.

Ectocarpus siliculosus.

Ectocarpus siliculosus, plurilocular sporangia.

Ectocarpus siliculosus, plurilocular sporangium with two-celled pedicel.

Order Ectocarpales

Family Chordariaceae

Elachista Duby

Small, epiphytic thalli comprising an adpressed basal layer and erect branched filaments. Reproductive structures borne terminally or laterally in filaments, plurilocular sporangia uniseriate, unilocular sporangia obovate. There are 24 currently recognised species worldwide.

One species of Elachista, E. endarachnae, was described from the south coast (Stegenga et al. 2002), but later ascribed to the new genus Elachistiella (Cassano et al. 2004; see under Elachistiella endarachnae), the latter genus based on its possession of two types of plurilocular structures: multiseriate 'ectocarpoid' structures developing from the apices of filaments, and intercalary structures. Stegenga et al. (2002) note the occurrence of 'at least two more species of Elachista on the South African south coast' that could not be described on account of insufficient material. Two pressed specimens in BOL, epiphytic on Sargassum spp., appear similar to Elachista nigra Takamatsu, a species from Japan, California and Australia that possesses only apical plurilocular structures (e.g. see Womersley 1987). In addition to noting these, we briefly describe a third species below.

Elachista species indet.

Parenchymatous basal part very small, vegetative filaments rather sparse, often somewhat curved, to 600 x 22,5 µm, the cells about as long as broad, somewhat swollen. Plurilocular sporangia abundant, uniseriate, consisting of 4-10 cells, measuring up to 35 x 7.5 µm.

Collections, ecology and regional distribution

Found once at Cape Padrone, 26-10-2003 (slide EC1935), epiphytic on Sargassum (or possibly Cystoseira sp. – identity of host uncertain).

Elachista sp, Cape Padrone, stained slide material.

Elachista sp, Cape Padrone, stained slide material.

Order Ectocarpales

Family Chordariaceae

Elachistiella endarachnae (H.Stegenga, J.J.Bolton, & R.J.Anderson) V.Cassano, Y.Yoneshigue-Valentin, & M.J.Wynne 2004: 335

Plants forming tiny brown cushions, up to 0.5 mm tall, usually on the blades of Petalonia (ex Endarachne) binghamiae, but also found on other large seaweeds (see below). Structure of entangled basal filaments attached by rhizoids; radiating erect, branched filaments forming a pseudoparenchymatous medulla, filaments 6-20 µm in diameter; medulla bearing cortex of erect assimilatory filaments each up to 22.5 µm in diameter, with basal meristematic zone and cells cylindrical to somewhat barrel-shaped, each containing several disc-shaped or irregularly-shaped parietal plastids. Lateral branches of filaments arising below meristematic zone and developing into new assimilatory filaments or plurilocular sporangia and paraphyses. Paraphyses curved, up to 15(-20) cells long, ca. 14 µm in diameter, with few plastids.

Plurilocular sporangia solitary, conical to cylindrical, multiseriate, up to 150 µm long and 30 µm in diameter, containing up to 50 rows of loculi, each row with many small loculi. Plurilocular structures also formed in mid to apical regions of assimilatory filaments and sometimes in apical cells of paraphyses, by transformation of vegetative cells that barely increase in diameter.

Collections, ecology and regional distribution

Reported to be epiphytic on Petalonia binghamiae. Recorded from the type locality at Morgan Bay but also found at Mkambati (43-47), epiphytic on Halimeda cuneata and Anthophycus longifolius; bearing multilocular sporangia, presence of paraphyses however doubtful. Although the substrata are completely different from Petalonia (Endarachne) and each other, the plants were completely similar, with similar dimensions, so that there is no reason to consider a different identity.

World distribution: South African endemic.

Type locality: Morgan Bay, Eastern Cape, South Africa (Stegenga et al. 2002).

Notes: 1. This species was originally described as Elachista endarachne (Stegenga et al. 2002), but the new genus Elachistiella V.Cassano, Y.Yoneshigue-Valentin, & M.J.Wynne was erected to accommodate it and an Elachista species from Brazil, based on their possession of two types of plurilocular structures: multiseriate 'ectocarpoid' structures developing from the apices of filaments, and intercalary structures.

Elachistiella endarachnae slide of type specimen (BOL), 2-3 mm long, showing basal portion and erect filaments.

Elachistiella endarachnae slide of type specimen (BOL), detail of basal portion and erect filaments.

Elachistiella endarachnae detail of basal portion.

Elachistiella endarachnae terminal plurilocular sporangia.

Elachistiella endarachnae detail of terminal plurilocular sporangia.

Elachistiella endarachnae intercalary plurilocular sporangia.

Dictyotales

Dictyotaceae

Exallosorus harveyanus (Pappe ex Kützing) J.A.Phillips 1997: 307

Plants brown, up to about 5 cm tall, comprising broad fan-shaped lobes spreading more or less horizontally from a matted rhizoidal holdfast. Primary lobes 2-5 mm wide with short stipes splitting apically into broad (to 15 mm wide) secondary lobes formed by splits that penetrate about one third of the primary lobes. Blades without in-rolled apices, 6 cells and about 150 µm thick, markedly dorsiventral; upper and lower surfaces with one layer of small, pigmented cortical cells that are approximately square in cross-section and 15-20 µm in diameter; four layers of medullary cells, elongated in longitudinal section, ca. 50-100 µm long and 20-30 µm wide. Apices of blades comprising a single row of large, densely pigmented cells. Ventral surfaces of lobes commonly with rhizoids, even to distal parts of blades.

Sporangia in sori covered by conspicuous indusium, mainly on ventral surfaces of fronds, irregularly circular-ovate, ca. 350-1000 µm across. Sporangia generally rounded-elongate, ca. 50 µm long x 25 µm wide, with a stalk cell, each containing 8 spores when mature (KZN guide says 4!). Gametangia united in indusiate sori; antheridial sori up to 0.5 mm wide, in roughly transverse bands, almost colourless. Single antheridia ca. 100 µm high, 20 µm broad, with ca. 30 tiers of loculi; paraphyses absent. Oogonial sori up to 0.5 mm in diameter, oogonia up to ca. 120 x 35 µm.

Collections, ecology and regional distribution

Collected from False Bay, Western Cape, to Park Rynie, about 80 km south of Durban (17-50). Epilithic from the subtidal fringe down to at least 40 m depth.

World distribution: South African endemic.

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

Note: This species was previously known as Zonaria harveyana (Pappe ex Kützing) Areschoug, but was transferred to the new genus Exallosorus on the basis of reproductive characters (Phillips 1997).

Exallosorus harveyanus.

Exallosorus harveyanus, blade tips.

Exallosorus harveyanus, XS of mid-blade (False Bay specimen).

Exallosorus harveyanus, LS of mid-blade.

Exallosorus harveyanus, LS showing ventral attaching rhizoids (Bird Island slide specimen).

Exallosorus harveyanus, sections showing sporangial or gametangial sori. Right (below) in cross section; left (above) in longitudinal section (stained slide specimen).

 Exallosorus harveyanus, detail of cross section through blade and sorus (stained slide specimen).

 Exallosorus harveyanus, surface view of blade and sori. Note rather elongate shape of sporangia (or gametangia) in surface veiw (stained slide specimen).

Exallosorus harveyanus. 1. Habit. 2. Cross section . 3. Longitudinal section. 4. Section of male gametangial sorus. 5. Section of oogonial sorus. Drawings reproduced from Stegenga et al. (1997).

Order Ectocarpales

Family Acinetosporaceae

Feldmannia G.Hamel

Plants uniseriate, filamentous, forming tufts comprising erect filaments attached by entangled basal rhizoids. Erect filaments mainly unbranched, with basal meristematic zone of short cells, cells lengthening distally and tapering slightly. Branching when present usually near base of filaments. Cells with numerous discoid plastids each with one pyrenoid. Plurilocular sporangia borne below meristematic zones on erect filaments. Unilocular sporangia in similar position when present. Sporangia usually pedicellate.

There are 37 species described, of which 23 are accepted currently (Guiry & Guiry 2011). We record a probable total of four species on the south coast of South Africa, two of which may not have been described and are only noted here.

Key to south coast species

1a. Plurilocular sporangia globular to ovoid, filaments 25-50 µm diameter near base

Feldmannia globifera

1b. Plurilocular sporangia cylindro-conical to conical, filaments 20-25 µm diameter near base

2

2a. Plurilocular sporangia borne on one-celled pedicel

Feldmannia sp 1

2b. Plurilocular sporangia sessile

3

3a. Plurilocular sporangia up to 180 µm long and 40 µm diameter, rather conical, cells of filaments near base  0.5 to 1 times as long as broad

Feldmannia irregularis

3b. Plurilocular sporangia up to 100 µm long, 25 (-30) µm diameter, cylindrico-conical, cells of filaments near base  1.2 - 2 1 times as long as broad

Feldmannia sp 2

Order Ectocarpales

Family Acinetosporaceae

Feldmannia globifera (Kützing) G.Hamel 1939: 67

Plants brown, 0.5 – 2 cm long, usually epiphytic, filamentous, uniseriate, irregularly branched close to the base; attached by entangled rhizoids. Filaments 25-50 (60) µm in diameter, cells 1-3 (-4) times as long as broad; filaments mainly of uniform diameter but gradually tapering distally. Meristematic zone of short cells at the base of each filament. Cells with numerous discoid plastids each with one pyrenoid. Plurilocular sporangia borne on 1-3 celled pedicels, rarely sessile; globular to ovoid with rounded apex, 60-100 µm long x 50-80 µm in diameter. Unilocular sporangia rarely seen; in same position as plurilocular sporangia, ovoid, sessile (35-60 µm diameter).

Collections, ecology and regional distribution

Recorded from Tsitsikamma to Kenton-on –Sea (31-39). Epiphytic on larger algae such as Codium spp.

World distribution: Widespread in temperate regions (Guiry & Guiry 2011).

Type locality: Yugoslavia (Womersley 1987).

Feldmannia globifera, Tsitsikamma, sporangia near bases of filaments (stained slide material).

Feldmannia globifera, Tsitsikamma, plurilocular sporangium with pedicel (stained slide material).

Order Ectocarpales

Family Acinetosporaceae

Feldmannia irregularis (Kützing) G.Hamel 1939: XVII

Plants 0.5 to 6 cm long, sparsely branched, more so basally, with many erect axes arising from an entangled prostrate system. Filaments ca. 25 µm in diameter towards the base, tapering gradually towards the apex. Cells with numerous discoid plastids. Meristematic regions basal, with cells 0.5 – 1.0 times as long as broad; distally cells ca. 15 µm in diameter and commonly 2-3 times as long as broad. Lateral branches mostly short, often with meristematic zones near their bases. Plurilocular sporangia sessile, sometimes in secund series, cylindroconical, to 180 µm long x 40 µm in diameter. Unilocular sporangia not observed.

Collections, ecology and regional distribution

Mainly epiphytic on Codium spp. Recorded from Langebaan Lagoon on the west coast , then from False Bay along the entire south coast and coast of Kwazulu-Natal (17 – 58).

World distribution: Widespread on tropical and temperate coasts all over the world, including Namibia and Mozambique (Guiry & Guiry 2011).

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

Note: According to Womersley (1987) this species shows characters somewhat intermediate between Feldmannia and Hincksia.

Feldmannia irregularis, with plurilocular sporangia.

Feldmannia irregularis, conical plurilocular sporangia.

Feldmannia irregularis, with secund plurilocular sporangia.

Feldmannia irregularis, whole thalli with rhizoidal mass on left.

Feldmannia irregularis, a conical plurilocular sporangium (fresh material, Tsitsikamma).

Feldmannia irregularis, detail of thallus showing meristematic zone, endophytic filaments and plurilocular sporangia (reproduced from Stegenga et al. 1997).

Order Ectocarpales

Family Acinetosporaceae

Feldmannia sp 1

Plants brown, a few mm to 1 cm or longer, sparsely branched near base, attached by rhizoids. Filaments about 25 µm diameter near base, tapering slightly distally, cells 1.5 to 2 times as long as broad.

Plurilocular sporangia borne near bases of filaments, cylindro-conical, borne on one –celled pedicels, when mature 100-150 µm long and up to 40 µm in diameter. Unilocular sporangia not seen.

Collections, ecology and regional distribution

Recorded from Double Mouth (43), on Codium platylobium.

World distribution: unknown.

Feldmannia sp 1, with plurilocular sporangia near filament bases (Double Mouth specimens, stained slide).

Feldmannia sp 1, with plurilocular sporangia (Double Mouth specimens, stained slide).

Feldmannia sp 1, plurilocular sporangia (Double Mouth specimen, stained slide).

Feldmannia sp 1, plurilocular sporangia and pedicel (Double Mouth specimen, stained slide).

Order Ectocarpales

Family Acinetosporaceae

Feldmannia sp 2

Plants brown, a few mm to 1 cm or longer, sparsely branched near base, attached by rhizoids. Filaments 20-25 µm diameter near base, tapering slightly distally, cells 1.2 to 2 times as long as broad. 

Plurilocular sporangia borne near bases of filaments, cylindro-conical, sessile, when mature 80-100 µm long and ca 25 µm in diameter. Unilocular sporangia not seen.

Collections, ecology and regional distribution

Recorded from Mbotyi (47), on Codium platylobium.

World distribution: unknown.

Feldmannia sp 2, with plurilocular sporangia near filament bases and rhizoidal mass bottom right (Mbotyi specimen, stained slide).

Feldmannia sp 2, plurilocular sporangia (Mbotyi specimen, stained slide).

Order Sphacelariales

Family Stypocaulaceae

Halopteris filicina (Grateloup) Kützing 1843: 293

Plants brown, 2-3 cm tall, delicate and feathery, alternately pinnately branched, with a single main axis and up to 4 orders of laterals. Main axis ca. 100 µm in diameter except near base where somewhat corticated by down-growing rhizoids; these rhizoids forming matted holdfast. Successive orders of branches becoming progressively narrower. Structure of larger medullary cells covered by a single layered cortex of small cells, further cortication only near base of plant, by down-growing rhizoids.

Unilocular sporangia borne in axils of branches, ovoid, 50-60 µm long x 35-50 µm wide. Plurilocular sporangia not seen.

Collections, ecology and regional distribution

Recorded from the Agulhas Bank (deeper water off Cape Agulhas) to Aliwal Shoal in southern Kwazulu-Natal (23-50). Sublittoral: mainly a deeper water species, collected down to 38 m.

World distribution: tropical and warm temperate Atlantic, Mediterranean, Japan, New Zealand, Hawai'i (Guiry & Guiry 2012).

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

Note: This species was first recorded in South Africa by Anderson & Stegenga (1989) from Bird Island, Algoa Bay, at 20 m depth.

Halopteris filicina, 25 m depth, Agulhas Bank - greenish colour due to formalin preservation).

Halopteris filicina, 25 m depth, Agulhas Bank – basal part showing matted rhizoidal holdfast.

Halopteris filicina, Bird Island – stained slide material.

Halopteris filicina, Bird Island – cellular detail, stained slide material.

Halopteris filicina, Bird Island – stained slide material, detail of unilocular sporangia.

Halopteris filicina, Bird Island – stained slide material, vegetative structure.

Halopteris filicina, Bird Island – stained slide material, apical cells.

Sphacelariales

Stypocaulaceae

Halopteris funicularis (Montagne) Sauvageau 1904: 94

Plants light to dark brown, up to 20 cm long, comprising one to several much-branched axes, each profusely branched, with the appearance of a stiffly furry bottle-brush. Holdfast rhizoidal. Lateral branches produced in irregularly radial pattern by divisions of the apical cell. Some branches longer, little branched, others determinate, all branches tapering to a point. Main filaments in mid-lower regions with single layer of cortication by down-growing rhizoids. Phaeophycean hairs absent. Sporangia in dense clusters in axils of laterals, interspersed with curved multicellular paraphyses. Sporangia globose, 30-35 µm in diameter, terminal on a uniseriate stalk; parpahyses 15-20 µm in diameter, mainly uniseriate but with occasional longitudinal division. Gametophytes rare, probably dioecious. Oogonia spherical, up to 140 µm in diameter, each borne on a pedicel of up to 5 cells in clusters of up to 3 in axils of laterals. Antheridia not seen.

Collections, ecology and regional distribution

Recorded from Port Nolloth to Port Alfred (1-32). Found in the lower eulittoral and subtidal down to at least 12 m depth.

World distribution: Also known from Namibia, Argentina, Australia, Tasmania, Chile, Antarctica, Tristan da Cunha and South Georgia (Guiry & Guiry 2017).

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

Note: This species was previously called Stypocaulon funiculare (e.g. Stegenga et al. 1997), but the genus Stypocaulon was subsumed into Halopteris by Draisma et al. (2010). 

Halopteris funicularis, habit, False Bay.

Halopteris funicularis.

Halopteris funicularis. 1. Habit. 2. Thallus apex. 3. Details of older axis showing pattern of longitudinal and transverse separation (a.i. – initial of adventitious branchlet). 4. Oogonia. Reproduced from Stegenga et al. (1997) (as Stypocaulon funiculare).

Order Sphacelariales

Family Stypocaulaceae

Halopteris

Plants brown, a few to about 20 cm tall, arising from a matted rhizoidal holdfast and forming erect tufts or complanate thalli. Axes terete, profusely branched, structure of large medullary cells covered by a single layer of cortical cells, additional cortication near bases of thalli by down-growing rhizoids. Branching initiated below the conspicuous apical cell at the tip of each axis; branching pinnate or irregularly radial. Unilocular sporangia sometimes found in our species; gametangia relatively rare. Nineteen species are recognised worldwide (MD Guiry in Guiry & Guiry 2017); two are recorded on our south coast.

Key to the species

1. Branching radial, thalli a few to 20 cm tall, resembling furry brushes

H. funicularis

2. Branching alternately pinnate, thalli up to 3 cm tall, feather-like

H. filicina

Order Ectocarpales

Family Acinetosporaceae

Hincksia J.E.Gray

Thalli erect, filamentous, branched; chloroplasts discoid, numerous, parietal, with one pyrenoid each. Pattern of branching varies within genus; secund , irregular scattered or opposite depending on species. Plurilocular sporangia variable in position. Unilocular sporangia seldom found, when present in same position as plurilocular sporangia.

There are 26 currently recognised species worldwide, in this cosmopolitan genus (Guiry & Guiry 2011): three are recorded from the south coast, and we note an additional possibly undescribed species.

Hincksia is distinguished from Feldmannia by more profuse branching, meristematic zones at the bases of each lateral, relatively short laterals, sporangia above and below meristems, and normally sessile sporangia.

Key to the species

1a. Branching on main axes opposite, cortication of main branches below side branches, plurilocular sporangia ovoid

H. granulosa

1b. Branching on main axes irregular, secund or spiral, no cortication of axes, plurilocular sporangia elongate-ovoid or conical

2

2a. Branching irregular to secund above, plurilocular sporangia straight, subcylindrical

H. mitchelliae

2b. Branching spiral below,, unilateral and adaxial above, plurilocular sporangia elongate-ovoid to conical often with curved apices

H. sandriana

Order Ectocarpales

Family Acinetosporaceae

Hincksia granulosa (Smith) P.C.Silva in Silva, Meñez & Moe 1987: 130

Plants forming low turf with other filamentous algae or epiphytic. Thallus 0.5-3 (-6) cm high, a tuft of branching uniseriate filaments with numerous discoid plastids in each cell. Growth apparently diffuse or with fairly indefinite meristematic regions. Axes profusely branched in up to 4 orders, each successive order narrower; all filaments tapering gradually. Fully elongated cells of primary axis barrel-shaped, almost isodiametric, to 50-60 µm in diameter and 70-80 µm long. Terminal filaments ca. 15 µm in diameter. Main branching usually opposite, later branching irregular or secund, laterals occasionally recurved. Proximal regions of main branches corticated by downward-growing rhizoids, forming an attachment to the substratum at their bases. Plurilocular sporangia sessile, rarely with a single-celled pedicel, on adaxial side of later order of branches; ovoid, generally symmetrical, upwardly curved, to ca. 90 µm long and 60 µm in diameter.

Collections, ecology and regional distribution

Rare, found in lower eulittoral turfs and on Pyura. Recorded from Oudekraal on the west coast of the Cape Peninsula to the Cape Vidal area of Kwazulu-Natal (16-56).

World distribution: Widespread in temperate waters all over the world (Guiry & Guiry 2011).

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

Hincksia granulosa, profuse branching, opposite on main axes.

Hincksia granulosa, main axces with opposite branches.

Hincksia granulosa, ovoid plurilocular sporangium.

Hincksia granulosa, cortication of main branch by downgrowing rhizoids.

Hincksia granulosa, thallus apex (right); portions of fertile thalli with plurilocular sporangia (reproduced from Stegenga et al. 1997).

Order Ectocarpales

Family Acinetosporaceae

Hincksia mitchelliae (Harvey) P.C.Silva in P.C. Silva, Meñez & Moe 1987: 73, 130

Plants brown, epilithic or epiphytic, 0.5 – 4 (-10) cm long, uniseriate, filamentous, attached by entangled mass of rhizoids. Erect axes profusely branched , branching irregular to unilateral (secund) in distal regions. Filaments tapering gradually, cells in lower parts 30-60 µm in diameter and 1-2 times as long as broad, ultimate branches 20-60 µm in diameter , cells 4-6 times as long as broad. Meristematic regions scattered on main filaments and at bases of branches, scattered intercalary divisions sometimes present. Cells with many discoid plastids each with one pyrenoid. Plurilocular sporangia straight, sub-cylindrical, with rounded tapering ends; scattered but often unilateral/adaxial, sessile, 50-140 µm long x 20-40 µm in diameter. Sporangia often ripening in basipetal sequence. Unilocular sporangia not seen (reported in Australian specimens as ovoid and in similar positions to plurilocular sporangia).

Collections, ecology and regional distribution

Recorded from De Hoop to northern Kwazulu-Natal (24-58). Specimens from Mkambati on Anthophycus longifolius, and from the Kowie on Codium tenue (all bearing plurilocular sporangia).

World distribution: widespread in temperate and tropical seas (Guiry & Guiry Sept 2011).

Type locality: Massachusetts, U.S.A. (Silva et al. 1996).

Note: This taxon is cited by Kim (2010) as belonging to the genus Feldmannia and cited by Guiry & Guiry (2017) as Feldmannia mitchelliae (Harvey) H.-S.Kim.

Hincksia mitchelliae, Mkambati, on Anthophycus longifolius (stained slide material).

Hincksia mitchelliae, Mkambati, showing subcylindrical plurilocular sporangia (stained slide material).

Order Ectocarpales

Family Acinetosporaceae

Hincksia sandriana (Zanardini) P.C.Silva in Silva, Meñez & Moe 1987: 130

Plants brown, densely tufted, usually epiphytic, 0.5 – 5 cm long, attached by a mass of descending rhizoids that often arise above the basal cells of the filaments and cover them; branching spiral below and unilateral/adaxial above. Filaments widest in mid-regions, tapering gradually towards apices and slightly towards bases; in mid regions 20-30 (-50) µm in diameter, cells 0.5 – 1.2 times as long as broad. Meristems at base of each branch and sometimes intercalary. Cells with many discoid plastids each with one pyrenoid.

Plurilocular sporangia sessile in secund adaxial rows, often several to many on adjacent cells in a series; sporangia elongate –ovoid to conical, broadest in the middle, apex roundly tapering; apices often slightly curved. Sporangia 30-85 x 18-45 µm . Material collected from the Kowie with some unilocular sporangia, measuring 45-50 x 17-20 µm. (Unilocular sporangia reported in Australia, on the same plants as plurilocs: sessile, scattered or in rows, ovoid, 30-35 µm x 20-40 µm ).

Collections ecology and regional distribution

Recorded only from Tsitsikamma and Kowie Estuary (32-39), the latter on Polysiphonia kowiensis and bearing unilocular sporangia.

World distribution: widespread in temperate and tropical seas (Guiry & Guiry 2011).

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

Note: a possibly undescribed species of Hincksia was found on an entity found on Polysiphonia kowiensis in the Kowie Estuary. The thallus is ca. 10 mm tall. Cells are ca. 35 µm long at maximum, cylindrical, up to twice as long as broad. The filaments taper gradually to the apices. Rows of about four plurilocular sporangia are arranged on the first cells at the base of the laterals, ripening in acropetal sequence (the opposite order to H. mitchelliae). The plurilocular sporangia are rather broad below, gradually tapering to a point, measuring ca. 100 (- 175) X 35 µm (specimen slide number EC 1908 – see photograph).

Hincksia sandriana.

Hincksia sandriana, Kowie Estuary.

Hincksia sandriana, Kowie Estuary, detail of plurilocular sporangia.

Typical brown tufts of an unnamed Hincksia on Sargassum in a Tsitsikamma rock pool.

Hincksia sp, probably undescribed (see note under H. sandriana).

Order Ectocarpales

Family Scytosiphonaceae

Iyengaria stellata (Børgesen) Børgesen 1939: 91-95, figs. 23-25

Plants yellow-brown, forming thin, globose cushions, irregularly furrowed and convoluted, up to about 10 cm diameter and 3-4 cm high; the surface covered with knobbly protruberances. Thalli at first solid but older plants becoming hollow in the centre. Structure parenchymatous, the central medullary cells polygonal, thin-walled, up to 300 µm in diameter; cells decreasing in size towards the exterior, epidermal cells in surface view 8-15 µm in diameter, in section about as high as broad, with one parietal chloroplast. Hair bundles present, arising below the epidermis, scattered over the thallus. Plurilocular sporangia in superficial sori, 60 (-75) µm long, 6-12 µm broad, sori without paraphyses.

Collections, ecology and regional distribution

Epilithic or epiphytic in the lower eulittoral and rock pools. Recorded from False Bay to the Port Edward area of southern Kwazulu-Natal (17-48).

World distribution: Recorded from India, Pakistan and shores on the Arabian Sea, also from Singapore and Papua New Guinea (Guiry & Guiry 2011).

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

Note: The rather peculiar distribution of this species, as well as the very close relationship between Iyengaria and the genus Colpomenia, indicate that Iyengaria is in need of investigation and that the name Colpomenia capensis should perhaps be resurrected for South African I. stellata (Stegenga et al. 1997).

Iyengaria stellata, intertidal cushions, Arniston.

Iyengaria stellata, submerged specimen in rock pool, Haga Haga.

Iyengaria stellata, xs showing continuous, solid medulla.

Iyengaria stellata. 1. Habit. 2. Cross section of outer cell layers. Drawings from Stegenga et al. (1997).

Order Ectocarpales

Family Chordariaceae

Leathesia marina (Lyngbye) Decaisne 1842: 370

Plants yellow-brown, globose, convoluted, slippery, a few to ca. 8 cm in diameter; firm becoming hollow. Thallus largely of a medulla of large cells forming a branched network. Outer medullary cells ca. 80-130 µm long. Thin cortex of assimilatory filaments 3-4 µm in diameter and a few cells long, with enlarged terminal cell up to ca. 10 µm in diameter. Plurilocular sporangia branching laterally from cell at base of assimilatory filament, generally in groups of 3-5, uniseriate, ca. 3-5 µm in diameter and 30-35 µm long, with 10-12 locules. Unilocular sporangia unknown in South African material.

Collections, ecology and regional distribution

Recorded along the west coast, south coast and into Kwazulu-Natal as far as Mission Rocks. Epilithic or epiphytic in the eulittoral zone (1-56).

World distribution: Widely distributed in temperate seas, including coast of Namibia (M.D. Guiry in Guiry & Guiry 2014).

Type locality: ('in Confervis maris occidentalis' (Silva et al. 1996).

Note: Superficially very similar to Colpomenia sinuosa, but the latter is much less firm and has a cortex that is obviously parenchymatous. Previously known as Leathesia difformis, but renamed for reasons of nomenclatural priority (MD Guiry in Guiry & Guiry 2014).

Leathesia marina in rock pool.

Leathesia marina, xs showing filamentous cortex underlain by medulla.

Leathesia marina, squash preparation of cortical filaments.

Leathesia marina, branched network of medullary cells

Leathesia marina. 1. Habit, on Chordariopsis capensis. 2. Section, with plurilocular sporangia (reproduced from Stegenga et al. 1997).

Order Ectocarpales

Family Chordariaceae

Leptonematella fasciculata (Reinke) P.C.Silva 1959: 63

Plants to 2.5 mm long, light brown, comprising dense tufts of erect filaments borne on a disc-like base of branched, radiating filaments; epilithic, epiphytic or epizoic. Erect filaments rather flaccid, uniseriate, simple or branched basally, cells barrel-shaped to square below and 6-8 µm wide, becoming rectangular above, 7-10 (-16) µm wide, 1-3 x as long as broad, each with several discoid plastids; intercalary meristem near base.

Unilocular sporangia not seen in our material. Plurilocular sporangia common, terminal or intercalary, in uniseriate series; extending laterally and becoming broader than vegetative cells, sometimes protruding laterally and to at least 18 µm wide.

Collections, ecology and regional distribution

Only collected at Tsitsikamma (39). Epiphytic on a Polysiphonia sp.

World distribution: Arctic, cold temperate and temperate localities (Guiry & Guiry 2012).

Note: See Fletcher (1987) for a description of material in the British Isles: Unilocular and plurilocular sporangia reported to occur on the same plants; unilocular sporangia lateral at base of erect filaments, sessile or with 1-several stalk cells, 80-120 µm long.

Leptonematella fasciculata, whole thallus, Tsitsikamma (slide specimen).

Leptonematella fasciculata, base of thallus, Tsitsikamma (slide specimen).

Leptonematella fasciculata, upright filaments, Tsitsikamma (slide specimen).

Leptonematella fasciculata, vegetative filaments and plurilocular sporangia.

Order Ectocarpales

Family Chordariaceae

Levringia filiformis Kylin 1940: 15, pl. 1: fig. 3

Plants brown, soft and velvety, flaccid, cylindrical, sinuous, a few to 20 cm long and 2-4 mm in diameter, sparsely branched, usually near the base. Medulla multiaxial, comprising central axis of filaments and thin rhizoids, surrounded by transitional layer of radially branched cell rows and thin rhizoids. Central axis and transitional layer together up to 2 mm thick. Assimilatory filaments arising from transitional layer, 2-3 mm long, 15-20 µm wide, cells 2-5 times as long as broad. Plurilocular sporangia 75-100 µm long and 18-22 µm broad. Unilocular sporangia not seen.

Collections, ecology and regional distribution

Recorded from Tsitsikamma area to Cape Vidal area of northern Kwazulu-Natal (31-56). Epilithic in lower eulittoral, rock pools and shallow sublittoral.

World distribution: South African endemic.

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

Note: The differences between this species and Levringia natalensis (from the coast of Kwazulu-Natal) appear to be minor (Kylin 1940) and these entities require further study.

Levringia filiformis, attached to mussel shell.

Levringia filiformis, xs (stained slide material).

Levringia filiformis, xs showing cortical assimilatory filaments and plurilocular sporangia.

Levringia filiformis, xs showing outer layer of assimilatory filaments and plurilocular sporangia arising from transitional layer of radial filaments.

Levringia filiformis, detail of medullary filaments (squash preapration).

Order Dictyotales

Family Dictyotaceae

Lobophora variegata (J.V.Lamouroux) Womersley ex E.C.Oliveira 1977: 217

Plants dark brown through medium brown to yellowish-brown, rather variable in habit, ranging from prostrate loosely attached crusts to semi-erect, comprising flattened, fan-shaped or irregularly-shaped blades up to about 5 cm in diameter and ca. 300 µm thick, often with concentric growth lines; prostrate thalli attached by ventral rhizoids, erect thalli with rhizoidal holdfast and narrow stipe. Blade margins not in-rolled, meristem of marginal row of apical cells; tufts of short hairs on both surfaces. Medulla with single layer of large rectangular cells and 2-4 layers of smaller cells on either side; cortex of single layer, cortical cells forming visible longitudinal lines. Sporangia in sori, covered by indusium, scattered on both surfaces. Sporangia up to 120 µm long and 90 µm wide, without stalk cell, each containing 8 spores.

Collections, ecology and regional distribution

Recorded from East London eastward throughout Kwazulu-Natal (41-58). Epilithic, in rock pools, and from the sublittoral fringe to at least 45 m depth: very common on deep reefs and coral reefs.

World distribution: Widely distributed in temperate and tropical seas (Guiry & Guiry 2012).

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

Note: this entity includes a wide range of growth forms, and needs further study (Tronchin & De Clerk 2005).

Lobophora variegate.

Lobophora variegata seen underwater.

Lobophora variegata, cross section showing cell layers and large central cells.

Lobophora variegata, longitudinal section through 'joint' in frond showing cell layers and large central cells (stained slide preparation).

Order Ectocarpales

Family Chordariaceae

Myriocladia capensis J.Agardh 1848: 54

Plants dark brown, 20-30 cm long, soft and slippery, profusely branched in 1-3 orders, the last order of branches short (1-20 mm). Medulla of tightly packed unpigmented filaments of elongated cells 15 µm in diameter and 100-150 µm long. Cortex comprising two types of assimilatory filaments: short filaments ca. 500 µm long, ca.x 8 µm in diameter at apex tapering to the base with cells ca. 15-18 µm long, and long filaments ca. 2 mm long , ca. 20 µm wide at the apex with cells ca. 18 µm long tapering gradually and consistently to the base. Cells deeply indented at cross walls throughout except for short, narrow region at the base. Phaeophycean hairs sparsely present, similar in length to long assimilatory filaments. Unilocular sporangia clavate, with truncate apex. ca. 100 µm long x 35 µm wide.

Collections, ecology and regional distribution

Recorded along the west coast as far as De Hoop (1-24). Epilithic in lower eulittoral and rock pools, reported to be a summer annual, present between about September and January (Stegenga et al. 1997).

World distribution: Endemic to southern Africa. Not recorded in Namibia (Stegenga et al. 1997).

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

Myriocladia capensis, De Hoop specimen, ca. 15 cm tall.

Myriocladia capensis, xs of thallus.

Myriocladia capensis, xs showing cortex and unilocular sporangia.

Myriocladia capensis, xs showing short and long cortical filaments.

Myriocladia capensis, unilocular sporangia at base of filaments.

Myriocladia capensis, 1. Habit. 2. Detail of cortex with assimilatory filamnets and unilocular sporangia. 3. Mature unilocular sporangium. From Stegenga et al. (1997).

Order Ectocarpales

Family Chordariales

Myriogloea papenfussii Kylin 1940: 13-14, figs. 9a-c, pl. 1: fig. 1 ('Myriogloia')

Plants brown, flaccid, slippery, 40-80 cm long and to 4-9 mm thick, simple or with a few short branches; covered with assimilatory filaments ca. 1 mm long. Very mucilaginous, loosely structured and disintegrating readily between the fingers. Structure with a central hollow portion surrounded by unpigmented medullary filaments ca. 15 µm in diameter with cells ca. 30 µm long. Irregular central medulla giving rise to horizontal filaments bearing the pigmented cortical filaments. Cortex composed of filaments broadening consistently from base to apex, with a basal meristem. Cells at apex almost isodiametric, 15-30 µm in diameter, slightly indented at cross walls. Assimilatory filaments up to 1.5 mm long.

Unilocular sporangia sessile, clavate to ovoid, 120-180 µm long x 60-80 µm in diameter, often in small clusters from 3-4 consecutive cells below the meristem on assimilatory cells of cortex.

Collections, ecology and regional distribution

Recorded from Melkbossstrand on the west coast to Still Bay (15-26). Epilithic in lower eulittoral, particularly on exposed shores.

World distribution: Southern African endemic - also found in Namibia (Guiry & Guiry 2011).

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

Note: compared to Myriocladia capensis this species has thicker axes and a very loose construction.

Myriogloea papenfussii, west coast specimen.

Myriogloea papenfussii, fresh material, 6 cm-long part of thallus showing loose, soft texture.

Myriogloea papenfussii, squash preparation – cortical filaments.

Myriogloea papenfussii, unilocular sporangia.

Myriogloea papenfussii, unilocular sporangia and assimilatory filaments.

Myriogloea papenfussii : 1. Habit. 2. Unilocular sporangia. 3. Detail of assimilatory filaments. From Stegenga et al. (1997).

Order Ralfsiales

Family Neoralfsiaceae

This family was recently erected (Lim and Kawai in Lim et al. 2007) to accommodate the new genus Neoralfsia, which is based in Neoralfsia expansa (formerly Ralfsia expansa).

Neoralfsia expansa (J.Agardh) P.-E.Lim & H.Kawai ex Cormaci & G.Furnari in Cormaci et al. 2012: 510

Plants crustose, adhering closely to substratum, medium to dark brown, up to 10 cm across, varying from a smooth crust to patches and overlapping lobes. Crusts up to ca 300 µm thick, comprising a closely adherent basal layer of horizontal filaments attached by multicellular rhizoids, basal filaments bearing a distinct layer of erect filaments; erect filaments 12-15 µm in diameter and up to 15 cells long. Tufts of phaeophycean hairs arising from pits in thallus and scattered over surface. Unilocular sporangia in sori, clavate, up to 7-120 µm long and 25-30 µm wide, borne on 3-6 celled pedicels; surrounded by sterile paraphyses. Plurilocular sporangia in superficial sori, up to 50-60 µm long x 5 µm wide, on 2-4 stalk cells and with a sterile apical dome-shaped cell.

Collections, ecology and regional distribution

Common in the eulittoral, epilithic but also on animal shells. Recorded from the Cape Padrone area through to northern Kwazulu-Natal (38-58).

World distribution: Widespread in tropical and warm temperate seas, and also recorded from Namibia, Mozambique, but some records may represent undescribed species (Guiry & Guiry 2017).

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

Note: Neoralfsia expansa has a distinct cortex that in cross section is visible as a zone of erect filaments above the upward-curving medullary filaments. Ralfsia verrucosa comprises adherent filaments that curve upward, so that there is no distinct cortical zone. Also, unilocular sporangia in the former are borne on pedicels of 3-6 cells, while in R. verrucosa these sporangia are sessile or on a single-celled pedical. The two genera are distinct in terms of rbcl DNA sequences (see Lim et al. 2007).

Neoralfsia expansa, Mission Rocks, northern KwaZulu-Natal.

Neoralfsia expansa, Mission Rocks, northern KwaZulu-Nata, xs of crust growing on top of another crust, showing cortex and medulla.

Neoralfsia expansa, longitudinal section showing upward-curving medulla with cortex above.

Neoralfsia expansa, xs showing attaching rhizoids growing from basal layer.

Order Fucales

Family Sargassaceae

Oerstedtia scalaris (Suhr) Jensen 1974: 34, figs 15-20, pls. 5, 6, 13b

Plants dark brown to yellowish-brown, with tough rather rubbery texture, up to 70 cm tall, comprising a prominent, woody, conical holdfast bearing one or more main axes that in turn bear primary lateral branches with distichous, alternating arrangement of leaves (rarely, second order of lateral branches present). Main axis up to about 15 cm long, terete at base, becoming slightly compressed, perennial, giving rise to alternating, distichously-arranged primary laterals; primary laterals slightly compressed at base becoming strongly compressed distally, up to 30 cm long or longer, 2-4 mm wide, zig-zag in shape, bearing leaves in bilateral alternate arrangement. Leaves on subterete stalks, linear, smooth-margined, 5-15 cm long x 0.6-0.8 cm wide, faint 'midrib' sometimes visible ; apical cell 3 –sided, borne in slit-like pit at leaf apex.. Fertile branchlets borne in axils of leaves, up to 3 cm long, somewhat zig-zag in shape, bearing alternately arranged ultimate order of receptacular branchlets. Receptacular branchlets terete, 1-2 mm long, containing conceptacles spirally arranged in swollen distal portion. Male conceptacles most distal, each containing numerous antheridial filaments. Female conceptacles below males. Each containing a few large (ca. 50 µm diameter) unilocular sporangia around a central tuft of paraphyses.

Collections,ecology and regional distribution

Recorded from just west of Cape Agulhas to near Durban (22-51) in the shallow subtidal zone. It is not uncommon from Port Alfred to southern Kwazulu-Natal, but we have never seen it in the Agulhas Area.

World distribution: South African endemic.

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

Note: the perennating main axes are always shorter that the primary laterals, and often herbarium specimens consist only of one primary lateral, sometimes with a piece of the main axis attached to the base.

Oerstedtia scalaris, Port Alfred.

Oerstedtia scalaris, herbarium specimen to show holdfast.

Oerstedtia scalaris, herbarium specimen - one primary lateral showing leaves, fertile branches in axils.

Oerstedtia scalaris, detail of fertile branchlets in leaf axils (herbarium specimen).

Order Dictyotales

Family Dictyotaceae

Padina boryana Thivy in W.R. Taylor 1966: 355, fig. 2

Plants light brown with white calcified layer on upper surface, comprising erect, curled, funnel-shaped blades, often split longitudinally; up to about 5 cm tall. Blade margin distinctively in-rolled, blades to about 2 cm diameter; stipe to 0.5 cm long, holdfast fibrous. Blade about 50 µm thick at apex, ca 190 µm thick near base; calcification on dorsal surface imparting concentric light whitish bands; darker bands in between resulting from hair rows on ventral blade surface. Blade of two cell layers above, three below; dorsal cells about twice as long as ventral cells. Sporangial sori borne on ventral surface in concentric rings just above hair bands, four spores per sporangium, indusium visible only in young blades. Gametophytes not seen.

Collections, ecology and regional distribution

Known from The Haven (some 150 km west of Port St Johns) to northern Kwazulu-Natal (44-58). Epilithic, typically on rocky ledges where there is some sand, from the mid eulittoral to shallow sublittoral zone.

World distribution: Mozambique, Tanzania, Kenya and worldwide in tropical and warm temperate localities (Guiry & Guiry 2012).

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

Note: Tronchin & De Clerck (2005) point out that this species can be confused with young specimens of Padina boergesenii Allender & Kraft, although blades of the latter may have up to four layers of cells. In South Africa P. boergesenii is only recorded north of Sodwana Bay.

Padina boryana, pressed specimen (BOL).

Padina boryana, XS of distal region of blade showing two cell layers.

Padina boryana, cross section of blade (slightly oblique) showing inrolled margin.

Padina boryana, LS through blade a few mm behind margin, showing three cell layers (stained slide preparation, Mkambati).

Order Ectocarpales

Family Scytosiphonaceae

Petalonia binghamiae (J.Agardh) K.L.Vinogradova 1973: 31

Plants medium brown, ribbon-like, up to ca. 10 (-20) cm long and 5-10 (-25) mm wide, several blades borne from a single discoid holdfast. Blades 200-300 µm thick at centre, narrower at edges. Phaeophycean hairs, in bundles, abundant, individual hairs to 300 µm long. Structure of cortex of 2-3 (-4) layers of isodiametric cells ca. 6-10 µm in diameter, 1-2 layers of larger colourless outer medullary cells (often difficult to discern) covering a central region of a very loose network of medullary hyphae ca. 4-8 µm in diameter. Plurilocular sporangia forming a continous layer over surface of fertile blades; uniseriate, ca. 30 µm long x 5-7 µm wide with 5-7 locules per sporangium. Unilocular sporangia unknown.

Collections, ecology and regional distribution

Epilithic and epiphytic in the eulittoral zone and edges of rock pools (plants from high on the shore usually smaller than low-shore plants). Recorded from False Bay to Ballito in Kwazulu-Natal (17-52).

World distribution: scattered localities in various warm temperate locations; in southern Africa also found in Namibia (Guiry & Guiry 2011).

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

Note: Previously known as Endarachne binghamiae. May be confused with Petalonia fascia, a species found mainly on the west coast, but P. fascia has an almost solid medulla.

Petalonia binghamiae, tidal pool, Kei Mouth.

Petalonia binghamiae, exposed on shore at low tide, De Hoop.

Petalonia binghamiae, xs showing medulla with outer layer of large cells and inner layer of loose filaments (Port Edward specimen).

Petalonia binghamiae, xs showing cortex with plurilocular sporangia, Eastern Cape specimen.

Petalonia binghamiae, xs showing bundle of phaeophycean hairs.

Petalonia binghamiae,. 1. Habit. 2. Cross section. Reproduced from Stegenga et al. (1997).

Order Ectocarpales

Family Scytosiphonaceae

Petalonia fascia (O.F.Müller) Kuntze 1898: 419

Plants brown to yellowish-brown, foliaceaous, comprising several simple, linear to broadly lanceolate blades arising from a common holdfast. Blades up to 20cm long and 5 cm wide, the margins often ruffled; up to 120 µm thick, thicker when reproductive. Structure parenchymatous, with medulla of 2-4 cell layers and one or two layers of much smaller cortical cells on each side; epidermal cells each with one plastid. Bundles of hairs arising from the subcortex, scattered over blade surface. Plurilocular sporangia formed in large areas on both sides of blades; 4-8 straight rows of 4-6 loculi each developing from each epidermal cell; paraphyses absent. Unilocular sporangia not seen.

Collections, ecology and regional distribution

Found in rock pools and the shallow sublittoral. Recorded from the west coast to the Knysna area (1-30), but records may be confused with Endarachne binghamiae, (see note).

World distribution: worldwide in temperate and cold-temperate seas (Guiry & Guiry 2014).

Type locality: near Kristiansand, Norway (Silva et al. 1996).

Note: Anatomical examination is usually necessary to distinguish Petalonia fascia from Petalonia binghamiae.

Petalonia fascia, Knysna lagoon(BOL).

Petalonia fascia, (Morgan Bay, BOL).

Petalonia fascia. 1. Habit. 2. Cross section with plurilocular sporangia. Drawings from Stegenga et al. (1997).

Order Ectocarpales

Family Scytosiphonaceae

Petalonia Derbès & Solier

Thalli erect, simple blades with small holdfast and short stipe, a few to about 20 cm tall. Cortex of 1-2 layers of small, pigmented cells underlain by outer medulla of large colourless cells and inner medulla either of large colourless cells or loose hyphae (species specific); pheaophycean hair tufts present. Plurilocular sporangia in continuous sori on large areas of blades, unilocular sporangia unknown in our material, reported in some species to be borne on alternating crustose phase. Five species are currently recognized worldwide (Guiry & Guiry 2014). South African members of the genus include the entity previously known as Endarachne binghamiae (e.g. see Stegenga et al. 1997), now considered to be a species of Petalonia (Boo 2010). Two species of Petalonia are recorded on the south coast, but some records must be treated with caution because of the superficial similarity between the species.

Key to species

1a. Blades 200-300 µm thick at centre, central medulla of loose network of hyphae

P. binghamiae

1b. Blades to 120  µm thick at centre, central medulla of compact parenchymatous cells

P. fascia

Sphacelariales

Stypocaulaceae

Phloiocaulon suhrii (J.Agardh) P.C.Silva in P.C.Silva, Basson & Moe 1996: 579

Plants dark brown, up to 30 cm tall, with smooth, sparsely branched main axes ca 1mm in diameter bearing uncorticated, translucent determinate laterals ca 3-4 mm long. Laterals regularly alternately branched in one plane, occasionally with second order of branches; all branches of determinate laterals tapering to appoint, main axis of laterals ca 100 µm in diameter at base, primary branches of laterals ca 80 µm at base. Determinate laterals with (probably seasonal) production and loss from perennial axial system. Deciduous hairs in bundles in axils of young laterals. Main axis in cross section with primary filaments visible as central regular pattern of small squarish cells, secondary cortication visible as a mantle of larger elongate polygonal radiating cells; epidermal cells 3-8 µm in diameter.

Reproductive structures not seen in our material, but see Sauvageau (1914): unilocular sporangia in pairs in each axil, ca.100-120 µm in diameter, on very short pedicels. Plurilocular sporangia on separate plants, 145- 170 µm in diameter, with mixed clusters of micro- and macrogametangia in the same axil, each on a short wide pedicel. Microgametangia orange-brown with locules 4 µm in diameter, macrogametangia dark brown with locules ca. 8 µm in diameter.

Collections, ecology and regional distribution

Recorded from Betty's Bay in the Western Cape (Jackelman et al. 1991) to Qolora, just east of the Kei River (19-43). Found from the shallow subtidal to at least 12 m depth.

World distribution: South African endemic.

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

Note: this species was previously misidentified as Phloiocaulon squamulosum (Suhr) Geyler.

Phloicaulon suhrii, Qolora.

Phloicaulon suhrii, tip of axis with determinate laterals, fresh material.

Phloicaulon suhrii, branching of determinate laterals.

Phloicaulon suhrii, cell detail.

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

Order Ralfsiales

Family Ralfsiaceae

Ralfsia verrucosa (Areschoug) Areschoug in Fries 1845: 124

Plants crustose, to several cm or more across, yellow-brown to olive green, becoming dark brown or blackish when dry; often with concentric growth rings, but may be fragmented by grazing or develop overlapping lobes. Vegetative crust of closely-packed, upward-curving filaments arising from a horizontal layer that is basal or central in the crust. Crust often attached by multicellular rhizoids. Horizontal filaments ca. 5-8 µm in diameter with cells 10-15 (-30) µm long. Vertical filaments 6-8 cells long, tightly adherent, with similar diameter to horizontal filaments but cells slightly shorter, almost isodiametric except in surface layer, where cells are 12-15 µm long. Cells with one chloroplast. Phaeophycean hairs present in scattered bundles.

Unilocular sporangia in raised sori composed of tightly packed uniseriate paraphyses that are very narrow at the base and widen to ca. 5 µm at the apex, 10-15 cells long. Unilocular sporangia clavate, 60-120 µm long x 20-30 µm wide. Plurilocular sporangia in large sori, scarcely raised above thallus surface; sporangia tightly packed, without interspersed vegetative cells or paraphyses; sporangia uniseriate, up to 40 µm (10 cells) long, 3-4 µm in diameter, each with a slightly larger sterile terminal cell.

Collections, ecology and regional distribution

Common on west and south coast shores throughout the eulittoral zone and in pools, also often epizoic on limpets and snails. Recorded along the entire west coast to at least the northern Transkei region (1-47), but superficially very similar to Neoralfsia expansa, and where they overlap in distribution these taxa are probably often confused.

World distribution: Probably cosmopolitan on cold and warm-temperate coasts (Guiry & Guiry 2011).

Type locality: Western Götland, Sweden (Guiry & Guiry 2011).

Ralfsia verrucosa, Tsitsikamma.

Ralfsia verrucosa, xs of crust (stained slide).

Ralfsia verrucosa, xs of Tsitsikamma specimen showing structure of upper layer and unilocular sporangia.

Ralfsia verrucosa, xs of Tsitsikamma specimen showing structure and unilocular sporangia.

Ralfsia verrucosa. 1. Radial vertical section of thallus with several superimposed lobes and raised unilocular sporangial sori. 2. Radial section of thallus showing terminal plurilocular sporangia. 3. Unilocular sporangia and associated paraphyses. 4. Radial section showing median primary cell rows and hair bundles. Drawings from Stegenga et al. (1997).

Order Ectocarpales

Family Scytosiphonaceae

Rosenvingea intricata (J.Agardh) Børgesen 1914: 26

Plants yellowish-brown to pale brown, comprising soft, cushion-like masses of entangled, branched cylindrical to flattened thalli. Main branches 2-5 mm in diameter, tapering sharply to ca. 0.5 mm near branch tips; branches often adhering to each other. Branches hollow, with wall of 3 cell layers, cells of outer layer pigmented, 12-14 µm in diameter. Bundles of hairs scattered over surfaces. Plurilocular sporangia developing from epidermal cells, in sori.

Collections, ecology and regional distribution

Apparently rare on our coast. Recorded from a few sheltered localities: Hluleka to northern Kwazulu-Natal (45-58).

World distribution: worldwide in tropical and warm temperate seas.

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

Note: the only specimen in BOL is unsuitable for illustration, so we have re-drawn the illustration of Tanzanian material from Jaasund (1976).

Rosenvingea intricata, re-drawn from Fig 97, Jaasund (1976)

Order Dictyotales

Family Dictyotaceae

Rugulopteryx suhrii (Kützing) De Clerck & Coppejans in De Clerck et al. 2006: 1286

Thalli erect, to 15 cm tall, brown, non-iridescent. Attached by fibrous holdfast; branching sparse, dichotomous, lax, fronds 3-4.5 mm wide in between branching points; frond surfaces with hair tufts; frond margins smooth, apices rounded. Structure of single cortical layer and medulla that is multi-layered throughout proximal parts and near the margins of distal parts; medullary cells ca. 110-120 µm long, 70=80 µm wide, 85-105 µm high; cortical cells ca 15 µm long, ca 17-18 µm high and wide. Tetrasporangia on 2-celled stalks, 190-210 µm in diameter, in rectangular patches near apices. Gametangia not seen.

Collections, ecology and regional distribution

Recorded from Algoa Bay to Mission Rocks (36-56). Found in rock pools and the shallow subtidal zone, usually on exposed shores (Tronchin & De Clerck 2005).

World distribution: Also recorded from Cape Verde Islands and Sri Lanka (references in Guiry & Guiry 2016), but these records require confirmation.

Type locality: South Africa: Cape Province: Algoa Bay (as Zonaria marginata Suhr).

Note: previously known as Dictyota suhrii (e.g. Tronchin & De Clerck 2005), this taxon was placed in the genus Rugulopteryx that was erected by De Clerck et al. 2006.

Rugulopteryx suhrii. Pressed specimen, 'submerged rocks', Algoa Bay (BOL).

Rugulopteryx suhrii. Pressed specimen, Hluleka (BOL).

Order Fucales

Family Sargassaceae

Sargassum cymosum var scabriusculum Grunow 1916: 142 ('scabriuscula')

Plants dark brown to yellowish-brown, up to 20-30 cm high, attached to the substrate by a small conical holdfast to 1.5 cm wide that bears one to several terete perennial main axes up to 1.5 cm long and 0.5 cm in diameter. Main axes giving rise to several primary axes, terete spiny to muricate. Secondary axes shorter with fewer spines, alternately and spirally attached, bearing leaves, vesicles and receptacles. Leaves simple to bi- or trifid, linear to oblong, sometimes spathulate, 0.5 to 1.6 cm long and 0.1 to 0.25 cm broad, crypstostomata inconspicuous, midrib percurrent and slightly raised, pedicel short, basis asymmetrical and cuneate, margins smooth to serrulate, apex rounded to acute. Vesicles spherical to oblong and smooth, up to 3 mm in diameter, pedicel terete to flattened, seldom leaf-like, longer than the vesicle. Receptacles compound, terete, surface warty, attached in open clusters, often mixed with small leaves and vesicles.

Collections, ecology and regional distribution

Found from Kalk Bay in False Bay and eastwards along the entire coast up to at least Cape Vidal (17-56). A subtidal species that can be abundant in rock pools, especially in the upper intertidal.

World distribution: also recorded from the tropical and sub-tropical Atlantic (references in Guiry & Guiry 2016).

Syntype localities: near Rio de Janiero, Brazil; South Africa: Cape of Good Hope; Algoa Bay' "Caffraria" (Silva et al. 1996: 668).

Note: see Mattio et al. (2015) for further information on this and other species that occur in South Africa. These authors note that the molecular difference between this S. cymosum var scabriusculum and S. elegans is not great, but they separate them on mainly morphological grounds.

Sargassum sp. A- habit. B – leaves. C –– vesicles. D – receptacles. E – spiny/muricate axes.

Order Fucales

Family Sargassaceae

Sargassum elegans Suhr 1840: 257

Plants dark brown to yellowish-brown, up to 50-60 cm high, attached to the substrate by a small conical to rather flattened holdfast to 1.5 cm wide that bears one to several terete perennial main axes up to 2 cm long and 0.6 cm in diameter. Main axes giving rise to several primary axes, terete and smooth, sometimes with a few spines. Secondary axes shorter, alternately and spirally attached, bearing leaves, vesicles and receptacles. Leaves linear-lanceolate, 1.1 to 4 cm long and 0.3 to 0.7 cm wide, crypstostomata inconspicuous or few and scattered when visible, midrib percurrent and slightly raised, pedicel mostly non-existent, basis asymmetrical and cuneate, margins smooth, seldom slightly dentate, apex rounded to slightly acute. Vesicles spherical to oblong and smooth, up to 5 mm in diameter, pedicel flattened to leaf-like and longer than the vesicle. Receptacles compound, terete, attached in tight clusters, surface warty.

Collections, ecology and regional distribution

Found from Saldanha Bay on the west coast then south and eastwards along the entire coast up to Sodwana Bay (12-57). A subtidal species that can be abundant in rock pools.

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

Type locality: South Africa (Suhr 1840), 'Am Cap der guten Hoffnung' [between Omsamculo (Umzimkulu) and Omcomas (Umkomaas) rivers, Natal, South Africa fide Drège, 1843: 157] (Silva et al. 1996).

Note: see Mattio et al. (2015) for a recent taxonomic treatment of South African Sargassum species.

Sargassum elegans, Tsitsikamma rock pool.

Sargassum elegans, Tsitsikamma.

Sargassum elegans. A- habit. B – leaves. C – vesicles. D – receptacles.

Sargassum elegans, detail of thallus. From Stegenga et al. (1997).

Order Fucales

Family Sargassaceae

Sargassum C. Agardh

Thalli differentiated into holdfast, short primary axis and relatively long and re-branched primary laterals. Branches usually foliose (bearing leaf-like laterals). Vesicles present on thalli. Receptacles borne in the axils of laterals.

This is a large, mainly tropical genus with 336 species currently recognized (Guiry & Guiry 2014). Three are recorded from the south coast, with descriptions here by L. Mattio. (See Mattio et al. (2015) for a recent revision of South African Sargassum).

Key to south coast species

1a. Main axes triangular in cross-section

S. incisifolium

1b. Main axes terete in cross-section

2

2a. Main axes smooth

S. elegans

2b. Main axes with spines or studded with pointed swellings

S. cymosum var. scabriusculum

Order Fucales

Family Sargassaceae

Sargassum incisifolium (Turner) C. Agardh 1820: 14-15

Plants dark brown to yellowish-brown, up to 50-60 cm high, attached to the substrate by a large conical holdfast to 4 cm wide that bears one or several strong perennial main axes up to 6 cm long and 2 cm in diameter. Main axis giving rise to several primary axes, thick, smooth and triangular in cross-section, somewhat flattened and up to 0.8 cm large. Secondary axes shorter, alternately and spirally attached, bearing leaves, vesicles and receptacles. Leaves oblong-lanceolate, 3 to 7 cm long and 0.6 to 2.1 cm broad, patterns of darker brown colour visible on most of the blades, crypstostomata inconspicuous, midrib percurrent and raised, pedicel short sometimes bearing a few teeth, leaf base asymmetrical rounded or cuneate, leaf margins mostly smooth, partially incised, occasionally dentate, apex rounded to acute. Vesicles oblong often pointed at the apex or with a spine like mucro, up to 10 mm long and 9 mm large, pedicel terete and shorter than the vesicle. Receptacles simple, lanceolate, flattened, surface warty, edges deeply dentate, attached in open clusters by a very short pedicel.

Collections, ecology and regional distribution

Recorded from Platboombaai, just west of Cape Point, eastwards along the entire coast and into Mozambique (17-58). A subtidal species that can form large beds at depths from a few to at least 10 m, sometimes found in rock pools and the lower eulittoral.

World distribution: Also occurring in the south-east of Madagascar (L. Mattio pers. com.). Doubtful records from Mauritius as S. heterophyllum (Turner) C. Agardh (Dickie 1874, Jadin 1934, Børgesen 1941), Mozambique (Silva et al. 1996, Critchley et al. 1997) and India (Silva et al. 1996, Sahoo et al. 2001).

Type locality: Cape of Good Hope, South Africa (Turner 1811).

Note: Sargasum heterophyllm C. Agardh and Fucus heterophyllus Turner are recorded as heterotypic synonyms of S. incisifolium. See Mattio et al. (2015) for a recent taxonomic treatment of South African Sargassum.

Sargassum incisifolium, Arniston.

Sargassum incisifolium, A- habit. B – main axes. C – leaf arrangement. D – leaves. E – vesicles. F – receptacles.

Sargassum incisifolium, details of fertile thalli. Reproduced from Stegenga et al. (1997).

Order Sphacelariales

Family Sphacelariaceae

Sphacelaria brachygona Montagne 1843: 305

Plants dark brown, up to 15 mm long, uprights growing in tufts from a restricted base, attached by rhizoids. Main axes about 65 µm in diameter (ca. 40-50 µm at apex), secondary segments 35-40 µm long, with (2-) 4-6 (-8) cell walls visible. Branching relatively sparse, of 3-4 orders.

Propagules single or in pairs, ellipsoid becoming fusiform with a 2-4 celled pedicel and 1 or 2 small cells on the distal side midway between the arms, to 105 µm long (including the pedicel) and ca. 220 µm wide across the arms.

Collections, ecology and regional distribution

Recorded from False Bay to Mbotyi 'east of river mouth' (18-47). Found in intertidal turfs and sometimes in estuaries attached to littoral vegetation.

World distribution: widespread in tropical and warm temperate localities (Guiry & Guiry 2012).

Type locality: Brazil (Womersley 1987).

Sphacelaria brachygona, tuft of whole thalli (ca 13 mm high), Goukamma.

Sphacelaria brachygona, Keurboomstrand, with propagules.

Sphacelaria brachygona, propagule and detail of uprights.

Sphacelaria brachygona, detail of propagule.

Sphacelaria brachygona. 1. Erect axis with propagules. 2. Propagule in first stage of germination. Reproduced from Stegenga et al. (1997).

Sphacelariales

Sphacelariaceae

Sphacelaria Lyngbye in Hornemann

Thalli forming tufts or mats, attached by basal discs or rhizoids. Branches cylindrical, erect branches branched sparsely to profusely, without cortication in upper parts, with or without phaeophycean hairs. Growth apical; main axes with a large apical cell, laterals often with small conical apical cell. Reproduction by plurilocular and unilocular sporangia; most species also producing vegetative propagules (special vegetative branchlets, usually with characteristic shapes). Common in intertidal turfs on the south coast. At present 39 species are recognized worldwide, of which 3 have been recorded on the south coast (Guiry & Guiry 2012); two of these also occur on the west coast (Stegenga et al. 1997).

Key to species

1a. All axes about 25 µm diameter, propagules with long pedicel and two long arms at wide angle

S. rigidula

1b. Main axes more than 35 µm wide below, propagules on short pedicels and ellipsoid/fusiform

2

2a. Main axes ca. 65 µm diameter below (narrower above), ca. 5 cells visible per segment, propagules ellipsoid/fusiform with rounded tips

S. brachygona

2b. Main axes ca. 50 µm diameter or narrower below, propagules almost triangular in cross section with rather pointed tips

S. tribuloides

Order Sphacelariales

Family Sphacelariaceae

Sphacelaria rigidula Kützing 1843: 292

Plants brown, tufted, up to ca. 5 mm high, fairly delicate, usually only branched (sparsely) near the apex. Main filaments ca. 25 µm in diameter, segments 25-40 µm long with 1-5 longitudinal cell walls visible. Branches narrow at base, widening distally.

Propagules comprising an elongate pedicel up to 300 µm long, with 2 equal arms with a wide angle between them containing one hemispherical cell; arms of varying length (to 300 µm ), rarely once-branched. Other reproductive structures not seen.

Collections, ecology and regional distribution

False Bay (Western Cape), eastwards along the whole South African coast to northern Kwazulu-Natal (17-58). Epilithic and epiphytic (e.g. on Codium) in the intertidal zone.

World distribution: cosmopolitan in tropical and warm-temperate seas (Guiry & Guiry 2012).

Type locality: Sinai, Red Sea (Guiry & Guiry 2012).

Sphacelaria rigidula, Kini Bay, near East London.

Sphacelaria rigidula, Vleesbaai, stained slide material.

Sphacelaria rigidula, young propagules.

Sphacelaria rigidula, propagules. Reproduced from Stegenga et al. (1997).

Sphacelariales

Sphacelariaceae

Sphacelaria tribuloides Meneghini 1840: [2]

Plants brown, up to 20 mm tall, forming dense tufts from a restricted base, attached by filaments. Erect filaments sparsely branched, laterals similar to parent filaments, all filaments to equal heights. Filaments straight, 10-20 µm in diameter above, up to 50 µm in diameter below.

Propagules almost triangular in cross-section, 150-180 µm long and 100-130 µm across the arms, borne on 1-3 celled pedicel. Two arms of propagules distinct, tapering.

Collections, ecology and regional distribution

Recorded from Fish River area to northern Kwazulu-Natal (40-58). Apparently in intertidal to shallow subtidal turfs.

World distribution: widely distributed in tropical and temperate waters worldwide (Guiry & Guiry 2012).

Type locality: northern Italy (Womersley 1987).

Sphacelaria tribuloides, thalli with propagules.

Sphacelaria tribuloides, propagule (ca 100 µm across tips).

Sphacelaria tribuloides, tip of thallus.

Sphacelaria tribuloides, detail of vegetative cells

Order Scytothamnales

Family Splachnidiaceae

Splachnidium rugosum (Linnaeus) Greville 1830: xxxvi

Plants mid-brown to yellow-brown, up to 30 cm long but usually shorter, comprising a cylindrical main axis up to 1.5 cm in diameter and a single order of whorled or irregularly inserted , cylindrical basally constricted branches up to 1 cm in diameter. The swollen but turgid and wrinkled appearance of the plant gives rise to the common name 'dead man's fingers'. Structure pseudoparenchymatous, consisting of a surface meristematic epidermis of small cells (ca. 13 x 8 µm diameter), a pigmented cortex about 60 µm deep of closely packed isodiametric cells, an outer medulla of a reticulate network of filaments and an inner medulla of sparse, loosely arranged hyphae. Most of the thallus comprises the mucilaginous central region, which also contains sparse hyphae.

Unilocular sporangia in sunken sub-spherical conceptacles that are up to 400 µm in diameter and visible as dark spots on surfaces of main axis and branches. Sporangia clavate to spindle-shaped, to 90 x 35 µm , in large numbers around inner wall of conceptacle, surrounded by phaeophycean hairs.

Collections, ecology and regional distribution

Common in the mid-shore, Recorded along the entire west coast and along the south coast as far as the East London area (1-41).

World distribution: Namibia, Chile, Tristan da Cunha, Amsterdam Island, New Zealand, Australia (Guiry & Guiry 2011).

Note: An alternate filamentous phase producing plurilocular sporangia is reported in Australia from culture (Price and Ducker 1966) and in the field (Womersley 1987).

Splachnidium rugosum, exposed during low tide.

Splachnidium rugosum with shell fragments attached to base.

Splachnidium rugosum (reproduced from Stegenga et al. 1997).

Order Ectocarpales

Family Chordariaceae

Stilophora flanaganii Kylin 1940: 53, pl. 8: fig. 21

Plants brown to yellowish-brown, comprising soft, entangled, irregularly branched cylindrical to flattened thalli up to about 25 cm long. Axes to 2 mm thick, tapering distally, growing tips with profuse assimilatory filaments that often extend beyond apices. Medulla of 4-5 longitudinal axial filaments, separating in older thalli to form central hollow. Cortex of several cells thick, with outer layer of small cells. Sori scattered over surfaces of axes, comprising unilocular sporangia, paraphyses and hairs. Pluriocular sporangia unknown.

Collections, ecology and regional distribution

Recorded from certain estuaries in the Eastern Cape (e.g. Haga Haga, Kleinemonde) (42-43). Usually epiphytic on, or tangled among salt-marsh plants.

World distribution: South African endemic.

Type locality; Haga Haga estuary mouth, Eastern Cape, South Africa (Silva et al. 1996).

Note: According to Silva et al. (1996) this entity was previously misidentified as Stilophora rhizodes.

Stilophora flanaganii, type specimen, BOL.

Stilophora flanaganii, herbarium specimen from Kleinemonde Estuary.

Stilophora flanaganii, surface of branchlet with sori of unilocular sporangia.

Stilophora flanaganii, tip of branchlet with assimilatory filaments.

Stilophora flanaganii, xs of outer layer.

Stilophora flanaganii, xs through branchlet, with sorus of unilocular sporangia.

Stilophora flanaganii, surface cells.

Order Ectocarpales

Family Chordariaceae

Streblonema codii E.S.Barton 1896: 194, fig. (1)

Plants minute, mainly endophytic (in Codium), comprising tufts of protruberant filaments arising from basal system of branched filaments that intertwine between cortical utricles of host. Cells of endophytic system elongate, ca. 10-15 µm in diameter, to 5 times as long as broad, giving rise to assimilatory filaments of similar diameter, ca. 10-15 cells long, protruding from the host tissue and tapering slightly at their tips. All cells approximately isodiametric with one or two irregularly-shaped parietal chloroplasts. Plurilocular sporangia multiseriate, terminal on assimilatory filaments, to 45 µm long and 15 µm in diameter.

Collections, ecology and regional distribution

Found on Codium (e.g. C. papenfussii ). Recorded from Betty's Bay on the west coast to the Knysna area (19-30).

World distribution: Also recorded from Japan (Guiry & Guiry 2011).

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

Streblonema codii, stained microscope slide.

Streblonema codii, detail of protruding assimilatory filaments and plurilocular sporangia.

Streblonema codii, microscopic habit with protruding assimilatory filaments and plurilocular sporangia (reproduced from Stegenga et al. 1997).

Order Dictyotales

Family Dictyotaceae

Stypopodium multipartitum (Suhr) P.C.Silva in P.C.Silva, Basson & Moe 1996: 611

Plants erect, yellowish-brown with blue iridescence when young, up to about 30 cm tall, comprising one to many fan-shaped blades attached by a matted rhizoidal holdfast. Blades complanate, irregularly split to lacerate in older plants, ca. 300 µm thick near base and ca. 100 µm thick distally; margins smooth, surface smooth when young, fertile blades becoming rugose; concentric rows of hairs creating visible bands. Structure of 4-6 (-9) layers of large medullary cells in cross section 35-75 µm wide x 25-35 µm high; cortex of single layer of cells in cross section 10-16 µm wide x 12-18 µm high. Sporangia in sori on both surfaces of blade, up to 80 µm in diameter and up to 120 µm long, with single stalk cell, each sporangium producing four spores; paraphyses absent. Sexual structures not seen.

Collections, ecology and regional distribution

Recorded from Arniston to northern Kwazulu-Natal (23-58). Found in rock pools, the sublittoral fringe, and subtidally down to 40 m depth.

World distribution: southern African endemic: also known from Mozambique (Tronchin & De Clerck 2005).

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

Note: This species was previously known as Stypopodium zonale (Lamouroux) Papenfuss.

Stypopodium multipartitum.

Stypopodium multipartitum underwater, showing bluish iridescence (Transkei).

Order Nemodermatales

Family Zeacarpaceae

Zeacarpa leiomorpha  R.J.Anderson, Simons & J.J.Bolton 1988: 320, figs 2-8

Plants forming smooth greenish-brown to dark brown crusts, sometimes streaked with golden yellow, a few to 10 cm or more in diameter and ca. 1mm thick. Structure pseudoparenchymatous; basal region of one to several layers of tightly adherent horizontal filaments, cells 15-25 µm long x 5-8 µm in diameter, curving upwards and giving rise to a layer of closely-packed vertical filaments with cells shorter but of similar diameter. Cells with several discoid parietal plastids. Lower surface of crust attached by numerous short multicellular rhizoids. Phaeophycean hairs only seen on material with plurilocular sporangia; few, in bundles as in Ralfsia.

Unilocular sporangia in sori formed from erect, loose, unbranched filaments up to 250 µm and 12-25 cells long, with lower and upper cells shorter and narrower than cells in the middle; sporangia fusiform to needle-shaped, 20-35 µm long x 4-6 µm in diameter, arising in clumps of several to ten, borne on a single lateral outgrowth from cell of loose soral filament; 1-3 sets of sporangia produced per soral filament; each sporangium containing 16 spores when mature. Although plurilocular sporangia are described and illustrated in Stegenga et al. (1997), it is not certain that these belong to Zeacarpa: they may be of Ralfsia.

Collections, ecology and regional distribution

Subtidal from just below LWS to at least 10 m depth, usually epilithic but sometimes epizoic on mollusk shells. Recorded from Yzerfontein on the west coast to Double Mouth, near Morgan Bay (14-43), but probably more widely distributed.

World distribution: South African endemic.

Type locality: Hout Bay, Western Cape (Anderson, Simons & Bolton, 1988).

Notes: 1. Vegetative crusts of Zeacarpa leiomorpha are indistinguishable from those of Ralfsia. The only practical morphological distinction between these genera relies on the unilocular sporangia.

2. The recent molecular study of Kawai et al (2016) erected the new Family Zeacarpaceae to accommodate this genus and species.

Zeacarpa leiomorpha, Grootbank (Tsitsikamma) showing typical streaked crust, rock ca 15 cm diameter.

Zeacarpa leiomorpha, XS of vegetative crust showing upward-curving lines of cells.

Zeacarpa leiomorpha, XS of type specimen, through sorus of unilocular sporangia and paraphyses.

Zeacarpa leiomorpha, squash preparation with loose reproductive filaments bearing unilocular sporangia.

Zeacarpa leiomorpha. 1. Radial vertical section through crust with sorus of plurilocular sporangia (but see note – this may be Ralfsia). 2. Section of vegetative thallus (note multicellular rhizoids). 3. Plurilocular sporangia (but see note). 4. Unilocular sporangia on paraphyses. Illustrations reproduced from Stegenga et al. (1997).

Order Dictyotales

Family Dictyotaceae

Zonaria C. Agardh

Plants erect, fan-shaped or much branched, parenchymatous, attached by matted rhizoidal holdfast. Growth by row of marginal apical cells. Thallus in cross-section with two cortical cells overlying each outer medullary cell.  Sporangia clavate/ovoid, lacking a stalk cell, borne externally in sori. Eight spores produced per sporangium. Thirteen species are currently recognized worldwide (M.D. Guiry in Guiry & Guiry 2014), of which two are found on the south coast.

Key to species

1a. Blades linear strap-shaped, ca. 200-300 µm and at least 10 cells thick near centre

Zonaria subarticulata

1b. Blades rather fan-shaped, ca. 100 µm and 6 cells thick near centre

Zonaria tournefortii

Order Dictyotales

Family Dictyotaceae

Zonaria subarticulata (J.V.Lamouroux) Papenfuss 1944: 339

Plants brown to greyish-brown, erect, up to 30 cm tall, flattened, profusely branched, comprising narrow (2-4 mm) strap-shaped blades arising from a matted rhizoidal holdfast. Branching in 2-3 orders, irregular, in single plane, branches at apex 3-4 mm wide, apices lobed. Blades 200-300 µm and 10-14 cells thick. Medulla of 8-12 cell layers, cells 15-20 µm in diameter, in longitudinal section ca. 80 µm long, cells containing many dark storage bodies imparting distinct banding pattern in longitudinal section. Cortex of smaller (20 µm diameter) pigmented cells; in cross section usually two cortical cells per medullary cell.

Unilocular sporangia in large sori, on both sides of the blade or more frequent on one side. Sporangia ovate, developing from an epidermal cell, at maturity ca. 150 X 75 µm, the contents developing into 8 spores. Majority of epidermal cells in a sorus each developing a multicellular paraphysis ca 7 cells long, narrow cylindrical at the base, the apical and subapical cells roundish and ca. 30 µm wide.

Plants dioecious. Female sori of much the same shape as sporangial ones but oogonia more slender than sporangia, ca. 185 X 60 µm; paraphyses in female sori of the same shape and density as in sporangial ones. Male gametangia in large sori covering much of the width of a blade. Male gametangia cylindrical, ca. 80 X 10 µm, about 30-35 cells high and 2-4 cells broad, with a sterile cell on top. Male sori without sterile filaments.

Collections ecology and regional distribution

Recorded from False Bay (but rare there) to northern Kwazulu-Natal (18-58). Common on the south coast in rock pools and the sublittoral zone down to 40 m depth. Often abundant on the walls of wave-washed gulleys.

World distribution: also recorded from Mozambique, Madagascar and the Mascarene Islands (Tronchin & De Clerck 2005).

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

Zonaria subarticulata, Arniston.

Zonaria subarticulata, longitudinal section through mid-blade.

Zonaria subarticulata, cross section through male sorus (Mkambati, stained slide preparation).

Zonaria subarticulata, cross section through probable female sorus (Mkambati, stained slide preparation).

Zonaria subarticulata, cross section through sorus of probable unilocular sporangia (Tsitsikamma, stained slide preparation).

Zonaria subarticulata, cross section through male sorus, detail (Mkambati, stained slide preparation).

Zonaria subarticulata, . 1. Habit. 2. Longitudinal section. 3. Cross section. Drawings reproduced from Stegenga et al. (1997).

Order Dictyotales

Family Dictyotaceae

Zonaria tournefortii (J.V.Lamouroux) Montagne 1846: 32-33

Plants erect, a few to ca. 15 cm tall, yellowish-brown to dark brown, comprising one to several sub-dichotomously to irregularly branched axes arising from a densely matted rhizoidal holdfast; axes flattened, ca. 2-5 (-10) mm wide, with visible midrib, widening distally into wedge-shaped or fan-shaped blades; blades with faint concentric zonation, often incised. Blades 6 cells and 80-100 µm thick near centre, 4 cells and ca. 60-70 µm thick near edges; in cross-section central two rows of medullary cells ca. 15-20 µm high x 10-15 µm wide, cortical cells smaller and usually wider than high. Sporangia in sori scattered irregularly over both surfaces of blades. Sporangia ca. 125 X 90 µm, at maturity dividing into 8 spores. Paraphyses 5-6 cells long overtop the sporangia, their apical cells are roundish, ca. 25 µm in diameter.

Collections, ecology and regional distribution

Recorded from De Hoop to northern Kwazulu-Natal. (24-58). Found from the sublittoral fringe to the sublittoral (at least 10 m depth), not common (much scarcer that Z. subarticulata).

World distribution: World distribution: widespread in the tropical/warm temperate Atlantic and Mediterranean (Guiry & Guiry 2012).

Syntype localities: Corsica, southern France and Italy (Silva et al. 1996).

Note: Littler & Littler (2000) state that the sporangial sori have no sterile hairs. Their illustration shows a somewhat different cell arrangement in cross-section.

Zonaria tournefortii, De Hoop.

Zonaria tournefortii, specimen out of water, ca 6 cm long, Mkambati.

Zonaria tournefortii, detail of sori on apical blade.

Zonaria tournefortii, basal part of fronds.

Zonaria tournefortii, cross section of central part of blade showing 6 cell layers.

Zonaria tournefortii, cross sectin showing probable unilocular sporangia (fresh material, Hluleka).

Zonaria tournefortii, cross section showing probable unilocular sporangia (stained slide material, Mzamba).

REFERENCES

References to South Coast Phaeophyceae

Agardh, C.A. 1820 '1821'. Species algarum rite cognitae, cum synonymis, differentiis specificis et descriptionibus succinctis. Volumen primum. Pars prima. pp. [i-iv], [1]-168. Lundae [Lund]: ex officina Berlingiana.

Agardh, J.G. 1848. Species genera et ordines algarum, seu descriptiones succinctae specierum, generum et ordinum, quibus algarum regnum constituitur. Volumen Primum. Algas fucoideas complectens. pp. [i-vi], [i]-viii, [1]-363. Lundae [Lund]: C.W.K. Gleerup.

Anderson, R.J. & Stegenga, H. 1989. Subtidal algal communities at Bird Island, Eastern Cape, South Africa. Botanica Marina 32: 299-311.

Anderson, R.J., Simons, R.H. & Bolton, J.J. 1988. Zeacarpa leiomorpha (Ralfsiaceae), a new genus and species of crustose marine Phaeophyceae from southern Africa. Phycologia 27: 319-326.

Barton, E.S. 1896. Cape algae. Journal of Botany, British and Foreign 34: 193-198, 458-461, 5 Figs.

Batters, E.A.L. 1902. A catalogue of the British marine algae. Journal of Botany, British and Foreign 40(Supplement): 1-107.

Bolton, J.J. (1996). Patterns of species diversity and endemism in comparable temperate brown algal floras. Hydrobiologia 326/327: 173-178.

Bolton, J. J. & Anderson, R,J. 1994. Ecklonia. In: The Biology of Economic Algae. I. Akatsuka (Ed.). SPB Academic Publishing, The Hague, Netherlands, pp. 385-406.

Bolton, J.J. & Anderson, R.J. 1987. Temperature tolerances of two southern African Ecklonia species (Alariaceae, Laminariales) and of hybrids between them. Marine Biology. 96: 293-297.

Bolton, JJ, Anderson, RJ, Smit, AJ &Rothman, MD. 2012. South African kelp moving eastwards:  the discovery of Ecklonia maxima (Osbeck) Papenfuss at De Hoop Nature Reserve. Short communication. African Journal of Marine Science 34: 147-151.

Bolton. J. J. & Stegenga, H. 1987. The marine algae of Hluleka (Transkei) and the warm temperate/sub-tropical transition on the east coast of southern Africa. Helgoländer Meeresuntersuchungen 41: 165-183.

Boo, S.-M. 2010. Scytosiphonaceae, Petrospongiaceae. In: Algal flora of Korea. Volume 2, Number 1. Heterokontophyta: Phaeophyceae: Ectocarpales. Marine brown algae I. (Kim, H.-S. & Boo, S.-M. Eds), pp. [155]-185. Incheon: National Institute of Biological Resources.

Boo, S.M., Lee, K.M., Cho, G.Y. & Nelson, W. 2011. Colpomenia claytonii sp. nov. (Scytosiphonaceae, Phaeophyceae) based on morphology and mitochondrial cox3 sequences. Botanica Marina 54(2): 159-167.

Börgesen, F. 1914. The marine algae of the Danish West Indies. Part 2. Phaeophyceae. Dansk Botanisk Arkiv 2(2): 68, 44 figs.

Börgesen, F. 1939. Marine algae from the Iranian Gulf especially from the innermost part near Bushire and the Island Kharg. In: Danish Scientific Investigations in Iran, Part 1. (Jessen, K. & Spärck, R. Eds), pp. 47-141. Copenhagen: Ejnar Munksgaard.

Börgesen, F. 1941. Some marine algae from Mauritius. II. Phaeophyceae. Kongelige Danske Videnskabernes Selskab, Biologiske Meddelelser 16(3): 81, 24 figs, 8 plates.

Cassano, V., Yoneshigue-Valentin, Y. & Wynne, M. J. 2004. Elachistiella leptonematoides gen. et sp. nov. (Elachistaceae, Phaeophyceae) from Brazil. Phycologia 43: 329-340.

Cho, G.Y, Rousseau, F., Reviers, B. de & Boo, S.M. 2006. Phylogenetic relationships within the Fucales (Phaeophyceae) assessed by the photosystem I coding psaA sequences. Phycologia 45: 512-519.

Critchley, A.T., Aken, M.E., Bandeira, S.O. & Kalk, M. 1997. A revised checklist for the seaweeds of Inhaca Island, Mozambique. South African Journal of Botany 63: 426-436.

De Clerck, O., Leliaert, F., Verbruggen, H., Lane, C.E., De Paula, J.C., Payo, D.I. & Coppejans, E. 2006. A revised classification of the Dictyoteae (Dictyotales, Phaeophyceae) based on rbcL and 26S ribosomal DNA sequence data analyses. Journal of Phycology 42: 1271-1288, 6 figs.

Decaisne, J. 1842. Essais sur une classification des algues et des polypiers calcifères de Lamouroux. Annales des Sciences Naturelles, Botanique, Seconde série 17: 297-380, pls 14-17.

Derbès, A. & Solier, A.J.J. 1851. Algues. In: Supplément au catalogue des plantes qui croissant naturellement aux environs de Marseille. (Castagne, J.L.M. Eds), pp. 93-121. Aix: Nicot & Pardigon.

Dickie, G. 1874. On the algae of Mauritius. Journal of the Linnean Society of London, Botany 14: 190-202.

Draisma, S.G.A., Ballesteros, E., Rousseau, F. & Thibaut, T. 2010. DNA sequence data demonstrate the polyphyly of the genus Cystoseira and other Sargassaceae genera (Phaeophyceae). Journal of Phycology 46(6): 1329-1345.

Draisma, SGA,  Prud'homme van Reine, WF & Kawai, H. 2010. A revised classification of the Sphacelariales (Phaeophyceae) inferred from a psbC and rbcL based  phylogeny. European Journal of Phycology 54 (3): 308-326.

Fletcher, R. L. 1987. Seaweeds of the British Isles. Volume 3. Fucophyceae (Phaeophyceae) Part 1. British Museum (Natural History), London. 359 pp.

Fries, E.M. 1845. Summa vegetabilium Scandinaviae, seu enumeratio, systematica et critica, plantarum tum cotyledonearum, quum nemearum inter mare occidentale et album, inter Eidoram et Nordkap, hactenus lectarum, una cum singulae distributione geographica. pp. Sectio prior: [i], [iii], [i]-258, signatures 1-16 in fours. Holmiae & Lipsiae [Stockholm & Leipzig]: A. Bonnier.

Gerloff, J. 1959. Bachelotia (Bornet) Kuckuck ex Hamel oder Bachelotia (Bornet) Fox?. Nova Hedwigia 1: 37-39.

Gray, J.E. 1864. Handbook of British Water-Weeds or Algae.. pp. i-iv, 1-123. London: R. Hardwicke.

Greville, R.K. 1830. Algae britannicae, or descriptions of the marine and other inarticulated plants of the British islands, belonging to the order Algae; with plates illustrative of the genera. pp. [i*-iii*], [i]-lxxxviii, [1]-218, pl. 1-19. Edinburgh & London: McLachlan & Stewart; Baldwin & Cradock.

Grunow, A. 1916. Additamenta ad cognitionem Sargassorum. Verhandlungen der Kaiserlich-Königlichen Zoologisch-Botanischen Gesellschaft in Wien 66: 1-48, 136-185.

Guiry, M.D. & Guiry, G.M. 2011-2017. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched about 150 times between October 2011 and October 2017.

Guiry M.D. in Guiry, M.D. & Guiry, G.M. 2014-2017. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched more than 30 times between September 2014 and October 2017.

Hamel, G. 1939. Phéophycées de France. Fasc. V. pp. i-xlvii + 337-432, figs 56-60, 10 plates. Paris.

Hamel, G. 1939. Sur la classification des Ectocarpales. Botaniska Notiser 1939: 65-70.

Harvey, W.H. 1841. A manual of the British algae: containing generic and specific descriptions of the known British species of sea-weeds and of Confervae both marine and fresh-water. pp. [i-v]-lvii, [1]-229. London: John Van Voorst.

Hoyt, W.D. 1920. Marine algae of Beaufort, N.C., and adjacent regions. Bulletin of the United States Bureau of Fisheries 36: 367-556, I-V (index), 47 figs, 9 tables, Plates LXXXIV-CXIX, 3 maps.

Jaasund, E. 1976. Seaweeds in Tanzania: A field guide. pp. 160. Tromsö: University of Tromsö.

Jackelman, J.J., Stegenga, H. & Bolton, J.J. 1991. The marine benthic flora of the Cape Hangklip area and its phytogeographical affinities. South African Journal of Botany 57: 295-304.

Jadin, F. 1934. Algues des îles de la Réunion et de Maurice. Annales de Cryptogamie Exotique 7: 147-172.

Jensen, A. 1974. Morphological studies in Cystoseiraceae and Sargassaceae (Phaeophyceae) with special reference to apical organization. University of California Publications in Botany 68: 1-61.

Kawai, H., Hanyuda, T., Bolton, J.J. & Anderson, R.J. 2016. Molecular phylogeny of Zeacarpa (Ralfsiales, Phaeophyceae) proposing a new family Zeacarpaceae and its transfer to Nemodermatales. Journal of Phycology. DOI: 10.1111/jpy.12419.

Kim, H.-S. 2010. Ectocarpaceae, Acinetosporaceae, Chordariaceae. In: Algal flora of Korea. Volume 2, Number 1. Heterokontophyta: Phaeophyceae: Ectocarpales. Marine brown algae I. (Kim, H.-S. & Boo, S.-M. Eds), pp. [3]-137. Incheon: National Institute of Biological Resources.

Kogame, K. 2001. Life history of Chnoospora implexa (Chnoosporaceaae, Phaeophyceae) in culture. Phycological Research 49: 123-128.

Kraft, G.T. 2009. Algae of Australia. Marine benthic algae of Lord Howe Island and the southern Great Barrier Reef, 2. Brown algae. pp. [i-iv], v-vi, 1-364, 107 figs. Erratum of fig. 73 from vol. 1. Canberra & Melbourne: Australian Biological Resources Study and CSIRO Publishing.

Kuntze, O. 1898. Revisio generum plantarum. Part 3 (3). pp. 1-576. Leipzig, London, Milano, New York, Paris: Arthur Felix, Dulau & Co., U. Hoepli, Gust. A. Schechert, Charles Klincksierck.

Kützing, F.T. 1843. Phycologia generalis oder Anatomie, Physiologie und Systemkunde der Tange... Mit 80 farbig gedruckten Tafeln, gezeichnet und gravirt vom Verfasser. pp. [part 1]: [i]-xxxii, [1]-142, [part 2:] 143-458, 1, err.], pls 1-80. Leipzig: F.A. Brockhaus.

Kützing, F.T. 1849. Species algarum. pp. [i]-vi, [1]-922. Lipsiae [Leipzig]: F.A. Brockhaus.

Kylin, H. 1940. Die Phaeophyceenordnung Chordariales. Acta Universitatis Lundensis 36(9): 1-67, 30 figs.

Laird, D.W. & van Altena I.A. 2006. Tetraprenyltoluquinols from the brown alga Cystophora fibrosa. Phytochemistry 67: 944-955.

Lamouroux, J.V.F. 1809. Exposition des caractères du genre Dictyota, et tableau des espèces qu'il renferem. Journal de Botanique (Desvaux) 2: 38-44.

Lamouroux, J.V.F. 1813. Essai sur les genres de la famille des thalassiophytes non articulées. Annales du Muséum d'Histoire Naturelle, Paris 20: 21-47, 115-139, 267-293, pls 7-13.

Lim, P.-E., Sakaguchi, M., Hanyuda, T., Kogame, K., Phang, S.-M. & Kawai, H. 2007. Molecular phylogeny of crustose brown algae (Ralfsiales, Phaeophyceae) inferred from rbcL sequences resulting in the proposal for Neoralfsiaceae fam. nov.. Phycologia 46(4): 456-466.

Littler, D.S. & Littler, M.M. 2000. Caribbean Reef Plants. OffShore graphics, Inc., Washington. 542 pp.

Lyngbye, H.C. 1819. Tentamen hydrophytologiae danicae continens omnia hydrophyta cryptogama Daniae, Holsatiae, Faeroae, Islandiae, Groenlandiae hucusque cognita, systematice disposita, descripta et iconibus illustrata, adjectis simul speciebus norvegicis. pp. [i]-xxxii, [1]-248, 70 pls. Hafniae [Copenhagen]: typis Schultzianis, in commissis Librariae Gyldendaliae.

Mattio, L., Anderson, R.J., & Bolton J.J. 2015. A revision of the genus Sargassum (Fucales, Phaeophyceae) in South Africa. South African Journal of Botany 98: 95-107.

Meneghini, G. 1840. Lettera del Prof. Giuseppe Meneghini al Dott. Iacob Corinaldi a Pisa. pp. [1-4]. Pisa: Tipografia Prosperi.

Montagne, [J.F.]C. 1846. Flore d'Algérie. Ordo I. Phyceae Fries. In: Exploration scientifique de l'Algérie pendant les années 1840, 1841, 1842...Sciences physiques. Botanique. Cryptogamie. (Durieu De Maisonneuve, M.C. Eds) Vol. 1, pp. 1-197. Paris: Imprimerie Royale, publiée par ordre du Gouvernement et avec le concours d'une Commission Académique.

Montagne, C. 1840. Plantae cellulares. In: Histoire naturelle des Iles Canaries. (Barker-Webb, P. & Berthelot, S. Eds) Vol.3, part 2, sect. ultima [4], pp. 137-192. Paris: Mellier.

Montagne, C. 1843. Quatrième centurie de plantes cellulaires exotiques nouvelles. Décades VII. Annales des Sciences Naturelles, Botanique, Seconde Série 20: 294-306, pl. 12.

Müller, D.G. & Parodi, E. 1994. Asteronema rhodochortonoides nov. comb. (Ectocarpales, Phaeophyceae) - a newly recognized taxon with stellate chloroplast arrangement. Phycologia 33: 471-474, 11 figs, 1 table.

Oliveira Filho, E.C. de 1977. Algas marinhas bentônicas do Brasil. pp. [i-iv], [1]-407. São Paulo, Brazil: Universidade de São Paulo, Instituto de Biociências.

Papenfuss, G.F. 1940. A revision of the South African marine algae in herbarium

Papenfuss, G.F. 1940. Notes on South African marine algae. I. Botaniska Notiser 1940: 200-226, 16 figs.

Papenfuss, G. F. 1942. Studies of South African Phaeophyceae: Ecklonia maxima, Laminaria pallida, and Macrocystis pyrifera. American journal of Botany 29: 15-24.

Papenfuss, G.F. 1944. Notes on algal nomenclature. III. Miscellaneous species of Chlorophyceae, Phaeophyceae and Rhodophyceae. Farlowia 1: 337-346.

Papenfuss, G.F. 1956. Notes on South African marine algae. IV. Journal of South African Botany 22: 65-77.

Phillips, J.A. 1997. Genus and species concepts in Zonaria and Homoeostrichus (Dictyotales, Phaeophyceae), including the description of Exallosorus gen. nov. European Journal of Phycology 32: 303-311, 15 figs, 5 tables.

Price, J. H. and Ducker S. C. 1966. The life history of the brown alga Splachnidium rugosum. Phycologia  5: 261-373.

Sahoo, D., Nivedita & Debasish. 2001. Seaweeds of Indian coast. pp. xxi + 283. New Delhi: A.P.H. Publishing.

Sauvageau, C. 1914. Remarques sur les Sphacélariacées. Vol. 3 pp. iii-xii, 481-634, 128 figs. Bordeaux.

Sauvageau, C. 1899. Les Acinetospora et la sexualité des Tiloptéridacées. Journal de Botanique, Morot 13: 107-127.

Sauvageau, C. 1904. Remarques sur les Sphacélariacées. Journal de Botanique [Morot] 18: 88-104.

Schmidt, O.C. 1938. Beiträge zur Systematik der Phaeophyten I. Hedwigia 77: 213-230.

Silva, P.C. 1959. Remarks on algal nomenclature II. Taxon 8: 60-64.

Silva, P.C., Basson, P.W. & Moe, R.L. 1996. Catalogue of the benthic marine algae of the Indian Ocean. University of California Publications in Botany 79: 1-1259.

Silva, P.C., Meñez, E.G. & Moe, R.L. 1987. Catalog of the benthic marine algae of the Philippines. Smithsonian Contributions to Marine Sciences 27: [i-ii] iii-iv, 1-179, 2 figs, 1 table.

Simons, R.H. 1967. A new species of brown alga from South Africa. Bothalia 9: 357-361, 1 fig, 1 plate.

Simons, R.H. 1970. Marine algae from southern Africa. 1. Six new species from the inter- and infra-tidal zones. Republic of South Africa, Department of Industries, Division of Sea Fisheries Investigational Report 88: (iii +) 13, 11 figs.

Steen, F., Vieira, C., Leliaert, F., Payri, E.C. & De Clerck, O. 2015. Biogeographic affinities of Dictyotales from Madagascar: a phylogenetic approach. Cryptogamie Algologie 36(2): 129-141.

Stegenga, H., Bolton, J. J. & Anderson, R. J. 2002. Elachista endarachnae sp. Nov. (Phaeophyceae, Elachistaceae), a peculiar representative of the genus in South Africa. Phycologia 41: 432-435.

Stegenga, H., Bolton, J.J. & Anderson, R.J. 1997. Seaweeds of the South African west coast. Contributions from the Bolus Herbarium 18: 655 pp.

Suhr, J.N. von 1840. Beiträge zur Algenkunde. Flora 23: 257-265.

Taylor, W.R. 1966. Records of Asian and western Pacific marine algae, particularly algae from Indonesia and the Philippines. Pacific Science 20: 342-359, 2 text figs.

Thunberg, CP. Symbolae Botanicae Upsalensis 4(3): 1-17.

Tronchin, E. M., & De Clerck, O. 2005. Brown Algae. In: De Clerck, O., J.J.Bolton, R. J. Anderson and E. Coppejans, 2005. Guide to the Seaweeds of Kwazulu-Natal. National Botanic Garden of Belgium, Brussels (Scripta Botanica Belgica), pp. 96-129.

Tronholm, A., Steen, F., Tyberghein, L., Leliaert, F. Verbruggen, H., Siguan, M.A.R. & De Clerck, O. 2010. Species delimitation, taxonomy, and biogeography of Dictyota in Europe (Dictyotales, Phaeophyceae). Journal of Phycology 46(6): 1301-1321.

Turner, D. 1809-1811. Fuci sive plantarum fucorum generi a botanicis ascriptarum icones descriptiones et historia. Fuci, or colored figures and descriptions of the plants referrred by botanists to the genus Fucus. Vol. 3 pp. [i], [1]-148 , [1-2], pl. 135-196 (col. copp. by W.J. Hooker). Londini [London]: typis J. M'Creery, impensis J. et A. Arch.

Uwai, S., Nagasato, C., Motomura, T. & Kogame, K. 2005. Life history and molecular phylogenetic relationships of Asterocladon interjectum sp. nov. (Phaeophyceae). European Journal of Phycology 40: 179-194.

Vinogradova, K.L. 1973. Anatomii roda Petalonia Derb. et Sol. (Scytosiphonales). Novosti Sistematiki Nizshikh Rastenij Botanicheskij Institut, Akademiya Nauk SSSR 10: 28-31, 2 figs.

Womersley, H.B.S. 1987. The marine benthic flora of southern Australia. Part II. pp. 481, 169 figs, 1 table, 8 plates, 4 maps. Adelaide: South Australian Government Printing Division.

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 ACINETOSPORACEAE

Acinetospora crinita

Feldmannia globifera

Feldmannia irregularis

Feldmannia sp.1

Feldmannia sp.2

Hincksia granulosa

Hincksia mitchelliae

Hincksia sandriana

FAMILY ASTEROCLADACEAE

Asterocladon rhodochortonoides

FAMILY BACHELOTIACEAE

Bachelotia antillarum

FAMILY ECTOCARPACEAE

Ectocarpus fasciculatus

Ectocarpus siliculosus

FAMILY CHORDARIACEAE

Asperococcus bullosus

Elachista sp.

Elachistiella endarachnae

Leathesia marina

Leptonematella fasciculata

Levringia filiformis

Myriocladia capensis

Myriogloea papenfussii

Stilophora flanaganii

Streblonema codii

FAMILY CHORDARIOPSIDACEAE

Chordariopsis capensis

FAMILY SCYTOSIPHONACEAE

Chnoospora minima

Colpomenia sinuosa

Iyengaria stellata

Petalonia binghamiae

Petalonia fascia

Rosenvingea intricata

FAMILY ZEACARPACEAE

Zeacarpa leiomorpha

FAMILY NEORALFSIACEAE

Neoralfsia expansa

FAMILY RALFSIACEAE

Ralfsia verrucosa

FAMILY SPLACHNIDIACEAE

Splachnidium rugosum

FAMILY SPHACELARIACEAE

Sphacelaria brachygona

Sphacelaria rigidula

Sphacelaria tribuloides

FAMILY STYPOCAULACEAE

Halopteris filicina

Halopteris funicularis

Phloiocaulon suhrii

FAMILY DICTYOTACEAE

Dictyopteris ligulata

Dictyopteris macrocarpa

Dictyopteris serrata

Dictyota dichotoma

Dictyota liturata

Dictyota naevosa

Dictyota sp.

Exallosorus harveyanus

Lobophora variegata

Padina boryana

Rugulopteryx suhrii

Stypopodium multipartitum

Zonaria subarticulata

Zonaria tournefortii

FAMILY CUTLERIACEAE

Aglaozonia (see Cutleria)

Cutleria multifida

FAMILY SPOROCHNACEAE

Carpomitra costata

Carpomitra longicarpa

FAMILY LESSONIACEAE

Ecklonia maxima

Ecklonia radiata

FAMILY BIFURCARIOPSIDACEAE

Bifurcariopsis capensis

FAMILY SARGASSACEAE

Anthophycus longifolius

Brassicophycus brassicaeformis

Cystophora fibrosa

Oerstedtia scalaris

Sargassum elegans

Sargassum incisifolium

Sargassum cymosum var scabriusculum

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.