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Electronic Flora of South Australia Species Fact Sheet

Platythalia angustifolia Sonder 1845: 51; 1846: 158.

Phylum Phaeophyta – Order Fucales – Family Cystoseiraceae

Selected citations: Gruber 1896: 24, pl. 7 figs 4,5. Harvey 1860: pl. 128. Womersley 1967: 256.


Carpoglossum angustifolium (Sonder) J. Agardh 1848: 194. Harvey 1860: p1. 128.

Thallus (Fig. 150A) dark brown, 20–80 cm long, with several complanately branched axes from the holdfast. Holdfast discoid-conical, soon becoming irregularly stoloniferous, 1–3 cm across: epilithic. Axes compressed, alternately pinnately branched, slightly flexuous, becoming denuded and relatively straight below, (2–) 3–4 (–5) mm broad and (0.5–) 1–2 mm thick, with laterals 0.5–1 cm apart. Laterals (Fig. 1558) simple to alternately pinnate, 1.5–4 cm long and (1–) 2–3 (–4) mm broad, basally constricted, entire, linear to lanceolate, with a slight costa. Structure of a medulla of elongate cells with few hyphae, and a cortex of isodiametric cells with a surface phaeoplastic meristoderm.

Reproduction: Thalli dioecious. Receptacles (Fig. 155B) developed from branches of upper laterals, simple or branched, (1–) 2–4 cm long and ( l-)L5–3 (–4) mm broad. Conceptacles in two rows with marginal or submarginal ostioles, unisexual; oogonia sessile, ovoid, 120–180 µm long and 60–100 in diameter, with simple paraphyses; antheridia sessile or on branched paraphyses, ovoid, 25–30 µm long and 10–15 in diameter.

Type from (probably) near Fremantle, W. Aust. (Preiss); in MEL, 18803.

Selected specimens: Flat Rocks, approx. 40 km S. of Geraldton, W. Aust., drift (Mitchell, 17.ix.1966; ADU, A30988). Port Denison, W. Aust., drift (Woelkerling, 8.xi.1968; ADU, A33158). Point Piquet, Cape Naturaliste, W. Aust., uppermost sublittoral (Womersley, 2.ix.1979; ADU, A51371-"Marine Algae of southern Australia" No. 58b). Flinders Bay, Augusta, W. Aust., drift ( Womersley, 1.ix.1979; ADU, A50635-"Marine Algae of southern Australia" No. 58c). Nanarup, E. of Albany, W. Aust., upper sublittoral (Parsons, 19.xi.1968; ADU, A33989-"Marine Algae of southern Australia" No. 58). Cape Riche, W. Aust. (Harvey).

Distribution map based
on current data relating to
specimens held in the
State Herbarium of SA

Distribution: From Flat Rocks, 40 km S. of Geraldton, to Cape Riche, W. Aust.

Taxonomic notes: The ostioles in P. angustifolia are often slightly displaced from a strictly marginal position, though not usually to the extent shown by Harvey (1860, pl. 128, fig. 2).


AGARDH, J.G. (1848). Species, Genera et Ordines Algarum. Vol. 1. (Gleerup: Lund.)

GRUBER, E. (1896). Ueber Aufbau and Entwickelung einiger Fucaceen. Bibl. Bot. 38, 1–32, Plates 1–7.

HARVEY, W.H. (1860). Phycologia Australica. Vol. 3, Plates 121–180. (Reeve: London.)

SONDER, O.W. (1845). Nova Algarum genera et species, quas in itinere ad oras occidentales Novae Hollandiae, collegit L. Preiss. Bot. Ztg 3, 49–57.

SONDER, O.W. (1846). Algae. In Lehmann, C., Plantae Preissianae. Vol. 2, pp. 148–160. (Hamburg.)

WOMERSLEY, H.B.S. (1967). A critical survey of the marine algae of southern Australia. II. Phaeophyta. Aust. J. Bot. 15, 189–270.

The Marine Benthic Flora of Southern Australia Part II complete list of references.

Author: H.B.S. Womersley

Publication: Womersley, H.B.S. (14 December, 1987)
The Marine Benthic Flora of Southern Australia
Part II
©Board of the Botanic Gardens and State Herbarium, Government of South Australia

Illustrations in Womersley Part II, 1997: FIGS 150A, 155B.

Figure 150 image

Figure 150   enlarge

Fig. 150. A. Platythalia angustifolia (ADU. A51371). B. Carpoglossum confluens (ADU, A57323).

Figure 155 image

Figure 155   enlarge

Fig. 155. A. Platythalia quercifolia (ADU, A30788). End of a lateral branch with scattered conceptacles. B. Platythalia angustifolia (ADU, A30988). Apex of a branch with laterals containing submarginal conceptacles. C. Myriodesma leptophyllum (ADU, A57326). Upper branches with conceptacles. D. Myriodesma serrulatum (ADU, A51221). Upper branches with raised conceptacles. E. Myriodesma integrifolium (ADU, A57457). Upper branches with conceptacles.

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