Cystophora brownii (Turner) J.Agardh

Scientific Description

Habit and structure. Thallus dark brown to grey-brown, 20–60 cm long, complanately and rigidly branched. Holdfast discoid-conical, 5–15 mm across; epilithic. Primary axes coarse, compressed, 3–7(–10) mm broad and (1–)2–4 mm thick, closely and alternately distichously branched from the face of the axis, below with prominent residues of secondary axes or laterals; secondary and tertiary axes numerous, retroflex, slenderer than the primary axis, usually with broad basal wings. Laterals 4–10 cm long, alternately distichous in the one plane, the whole lateral usually tapering in form from base to apex; ramuli rigid, terete to slightly compressed, with prominently rounded axils, (0.2–)0.5–2 cm long and 300–600 µm in diameter. Vesicles absent.

Reproduction. Thalli monoecious. Receptacles developed from ends of ramuli, simple, 2–6(–10) mm long and 0.5–1 mm in diameter, smooth to distinctly torulose, tapering. Conceptacles bisexual, few (4–8) per receptacle, ostioles usually scattered, occasionally in 2 or 3 rows, with simple paraphyses; oogonia sessile, ovoid, 95–150 µm long and 70–110 µm in diameter; antheridia sessile or on branched paraphyses, elongate-ovoid, 22–30 µm long and 8–12 µm in diameter.

Distribution. From Port Denison, W. Aust., around southern Australia to Victor Harbor and around Kangaroo I., S. Aust.; N.E. Tas.

Habitat. C. brownii is often plentiful in the upper sublittoral and deeper pools on coasts of moderate wave action, extending to a few metres deep.

[After Womersley, Mar. Benthic Fl. Southern Australia II: 386 (1987)]