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Electronic Flora of South Australia Species Fact Sheet

Cystophora gracilis Womersley 1964: 79, figs 19,20, pl. 6 fig. 2.

Phylum Phaeophyta – Order Fucales – Family Cystoseiraceae

Thallus (Fig. 142B) dark brown, 20–50 (–70) cm long, with a slender, fairly straight, primary axis bearing densely branched laterals and secondary axes. Holdfast discoid-conical, 3–10 mm across; epilithic. Primary axes in transverse section ovoid to compressed with rounded edges, 2–3 (–4) mm broad and 1–2 mm thick, tapering only slightly from base to apex, alternately distichously branched from the face of the axis at intervals of 0.5–1.5 cm, usually denuded below with inconspicuous branch residues to 1 mm long and the remaining secondary axes 2–6 cm apart; secondary axes usually inclined upwards and not retroflex, 5–10 (–15) cm long, 0.5–1 mm broad, closely branched. Laterals 0.5–6 (–10) cm long, alternately and fairly irregularly branched with irregularly subdichotomous, terete, ramuli, with broad but not rounded axils and not lying in one plane; ramuli 0.2–1 cm long, 0.2–1 mm in diameter. Vesicles absent.

Reproduction: Thalli monoecious. Receptacles (Fig. 145B,C) developed from ends of ramuli, simple, torulose, 2–8 (–10) mm long and 0.5–1 mm in diameter, with relatively few (4–10) closely adjacent conceptacles, with a sterile apical awn; occasional old receptacles with a conceptacle in the awn, the fertile region then 1.5–2 cm long. Conceptacles bisexual, ostioles more or less in two rows, with simple paraphyses; oogonia ovoid, sessile, 95–130 µm long and 60–80 µm in diameter; antheridia mainly near ostiole, sessile or on branched paraphyses, elongate-ovoid, 14–20 µm long and 10–14 µm in diameter.

Type from Vivonne Bay, Kangaroo I., S. Aust., in a large eulittoral pool, S. side of Ellen Point ( Womersley, 24.viii.1963); holotype in ADU, A26725-isotypes distributed in "Marine Algae of southern Australia" No. 55).

Selected specimens: Cowaramup Bay, W. Aust., 2–3 m deep (Clarke & Engler, 1.ix.1979; ADU, A50656). Lucky Bay, Cape Le Grand, W. Aust., upper sublittoral ( Womersley, 4.x.1979; ADU, A51149). Point Sinclair, S. Aust., upper sublittoral (Womersley, 25.i.1951; ADU, A13598). Masillon I., Isles of St Francis, S. Aust., 4–7 m deep (Shepherd, 5.i.1971; ADU, A38016). Wanna, S. Aust., sublittoral pools (Nizamuddin, 19.ii.1959; ADU, A24070). Sou' West R., Kangaroo I., W. Aust., 6 m deep (Mitchell, 24.viii.1963; ADU, A26812). Seal Beach, Kangaroo I., S. Aust., drift ( Womersley, 24.i.1957; ADU, A20736).

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

Distribution: From Cowaramup Bay, W. Aust. to Wanna, S. Aust. and Seal Beach, Kangaroo I., S. Aust., in the uppermost sublittoral and deep pools.

Taxonomic notes: C. gracilis is apparently not a common species, and is characterised by the slender axis, short, torulose receptacles with a sterile awn, and lack of vesicles.


WOMERSLEY, H.B.S. (1964). The morphology and taxonomy of Cystophora and related genera (Phaeophyta). Aust. J. Bot. 12, 53–110, Plates 1–16.

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 142B, 145B,C.

Figure 142 image

Figure 142   enlarge

Fig. 142. A. Cystophora brownii (ADU, A5862). B. Cystophora gracilis (ADU, A26725, holotype).

Figure 145 image

Figure 145   enlarge

Fig. 145. Receptacles of species of Cystophora. A. Cystophora brownii (ADU, A26713). B,C. Cystophora gracilis (ADU, A26725, holotype). D. Cystophora harveyi (ADU, A50628, holotype). E. Cystophora tenuis (ADU, A50627, holotype). F,G. Cystophora retorta (ADU, A26877). F. Secondary and tertiary axes and laterals. G. Receptacles. H. Cystophora siliquosa (ADU, A2812).

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