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Electronic Flora of South Australia Species Fact Sheet

Cystophora retroflexa (Labillardière) J. Agardh 1848: 242; 1896: 49.

Phylum Phaeophyta – Order Fucales – Family Cystoseiraceae

Selected citations: Lindauer et al. 1961: 299, pl. 70, upper. Womersley 1964: 89, figs 31,32, pl. 10 fig. 2.


Fucus retroflexus Labillardière 1806: 113, pl. 260.

Thallus (Fig. 1468) medium to dark brown, 0.5–1.5 (–2) m long, with the primary axes bearing alternate, fairly openly branched laterals and secondary axes. Holdfast discoid-conical, 0.5–1.5 cm across, with a single, short, subterete, stipe; epilithic. Primary axes compressed, 3–10 mm broad below and 1–3 mm thick, 2–5 mm broad above, narrow edged, usually fairly straight, with branching from the face of the axis; lower parts often denuded, with prominent residues 1–3 mm long, 1–5 mm apart; secondary axes usually retroflex, often with broad basal wings (but sometimes attached centrally to the primary axes), usually short (occasionally developing into long axes). Laterals (Fig. 149B,C) 2–8 cm long, usually irregularly radially branched (rarely subtristichous or subdistichous), with simple or branched, subterete, ramuli 2–4 cm long and 0.3–0.8 mm in diameter, straight to slightly undulate. Vesicles sparse to numerous, ovoid to subspherical, replacing basal one or two ramuli of laterals, petiolate, mutic, 4–10 mm long and 3–6 mm broad.

Reproduction: Thalli monoecious. Receptacles (Fig. I 49C) usually simple, relatively stout, compressed, 2–5 (–6) cm long and 1–2 (–2.5) mm broad, smooth to slightly torulose when fresh, drying with torulose margins, apex attenuate. Conceptacles (Fig. 1321) bisexual, usually adjacent, with two rows of ostioles along the margins, with simple paraphyses: oogonia sessile. ovoid, 80–100 µm long and 50–80 µm in diameter; antheridia on branched paraphyses, elongate-ovoid, 18–26 µm long and 8–12 µm in diameter.

Type from "Cape van Diemen" (S.F. Tasmania): in Fl.

Selected specimens: Victor Harbor, S. Aust., drift (Womersley, 2.x.1963; ADU, A26793). Vivonne Bay, Kangaroo I., S. Aust., drift (Womersley, 21.viii.1963; ADU, A26787). American R. inlet, Kangaroo 1., S. Aust., drift (Womersley, 2.vi.1947; ADU, A5716). Brighton beach, Port Phillip, Vic., drift (Womersley, 29.v.1948; ADU, A8345). Mallacoota Point, Vic., upper sublittoral (Womersley, 12.xi.1982; ADU, A55345). Boat Harbour Point, N. Tas., in mid eulittoral pool ( Womersley, 16.x.1982; ADU, A55755). Bombay Rock, Tamar Est., Tas., upper sublittoral (Womersley, 27.i.1949; ADU, A10354). Cape Sorell, Tas., in deep pools (Bennett, 4.ii.1955; ADU, A20593). Louisville, Prosser Bay, Tas., sublittoral (Olsen, 2.xi.1963; ADU, A26896). Marion Bay, Tas., drift (Higinbotham, 27.x.1963; ADU, A26883). Stewarts Bay (N. point), Port Arthur, Tas., 1 m deep (McGeary-Brown, 29.x.1986; ADU, A57386) and sublittoral (Cribb, 22.vi.1950; ADU, A16391). Great Taylor Bay, Bruny I., Tas., 2–7 m deep (Shepherd, 7.ii.1970; ADU, A35554). Eden, N.S.W., upper sublittoral pools (Womersley, 12.viii.1959; ADU, A23122). Hyams Beach, Jervis Bay, N.S.W., upper sublittoral pools ( Womersley, 16.i.1964; ADU, A27450). Cronulla, N.S.W. (Levring, 13.xi.1947; ADU, A56006).

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

Distribution: From Victor Harbor and Kangaroo I., S. Aust. around Victoria and Tasmania to Bondi, N.S.W.

New Zealand; Chatham Is, Auckland Is.

Taxonomic notes: C. retroflexa is essentially an eastern species, characterised by the fairly open branching with irregularly branched laterals, the vesicles, and the long, compressed, slightly torulose receptacles. In Tasmania it is common from low tide level to 12 m deep, with plants reaching 2 m long in shallow, protected, waters. At the western end of its range in South Australia, plants are recognisable with more difficulty, especially if not well developed and fertile. On the south-west coast of Western Australia, plants occur which also may be referable to C. retroflexa [e.g. Cowaramup, W. Aust., drift (Gordon, 16.xi.1968; ADU, A33127)]. These have receptacles similar to C. retroflexa but branching similar to C. harveyi. The Cystophora species in this region need further study.


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

AGARDH, J.G. (1896). Analecta Algologica. Cont. III. Ada Univ. lund. 32, 1–140, Plate 1.

LABILLARDIÈRE, J.J. (1806–1807). Novae Hollandiae Plantarum Specimen. Vol. 2. (Plates 231–265 in 1807). (Huzard: Paris.)

LINDAUER, V.W., CHAPMAN, V.J. & AIKEN, M. (1961). The marine algae of New Zealand. II. Phaeophyceae. Nova Hedwigia 3, 129–350, Plates 57–97.

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 1321, 146B, 149B,C.

Figure 146 image

Figure 146   enlarge

Fig. 146. A. Cvstophora congesta (ADU, A23980, holotype). B. Cvstophora retroflexa (ADU, A16391).

Figure 149 image

Figure 149   enlarge

Fig. 149. Receptacles of species of Cystophora. A. Cystophora congesta (ADU, A26738). A lateral with receptacles and a vesicle. B,C. Cystophora retroflexa (B, ADU, A26787; C, ADU, A26883). B. A secondary axis and laterals. C. A lateral with receptacles and a vesicle. D. Cystophora cvmodoceae (ADU, A2398l, holotype). A lateral and ramuli with vesicles. E–G. Cystophora subfarcinata (E, ADU, A6551; F, ADU, A5719; G, ADU, A19876). E. Laterals of the e-vesiculate form. F. Loosely branched laterals with vesicles. G. Much branched lateral with basal vesicles. H. Cystophora cuspidata (ADU, A21084).

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