Dictyota furcellata (C.Agardh) Grev.

Scientific Description

Habit and structure. Thallus medium to dark brown, usually 5–20 cm long with branches 0.3–1.0(–1.5) mm broad, mostly strictly dichotomously branched 2–10(–15) mm apart, with no or few proliferations (if present, then small and from lower parts), with acute to broad and often rounded axils, branches tapering only slightly. Holdfast of rhizoids from the basal, often entangled, branches; epiphytic or epilithic. Apical cell hemispherical and surmounting the narrow branch apex. Cortical cells 10–16(–18) µm across, L/B(1–)2–4. Hair tufts scattered, sparse but conspicuous, hairs 8–14 µmin diameter.

Reproduction. Tetrasporangia 80–120 µm in diameter, scattered singly or in small groups, usually sparse. Oogonial sori irregularly ovate, scattered, 200–400 µmlong and 150–350 µm across; oogonia 80–100 µm long and 40–60 µmin diameter. Antheridial sori elongate-ovate, scattered, 300–700 µmlong and 100–200 µm across.

Distribution.From the Dampier Archipelago, W. Aust., around southern Australia to Westernport Bay, Vic., and the N coast of Tas.

Habitat. D. furcellata occurs from rock pools on sheltered coasts to deep water.

[After Womersley, Mar. Benthic Fl. Southern Australia II: 196 (1987)]