- Reference
- Univ.Calif.Publ.Bot. 492 (1996)
- Conservation Code
- Not threatened
- Naturalised Status
- Native to Western Australia
- Name Status
- Current
Scientific Description
Habit and structure. Thallus dark brown-red, erect, 10–30 cm (–2 m) high, with radial, indeterminate, terete, heavily corticated branches for 3–4 orders, clothed with short tufts of ecorticate determinate laterals 2–4(–5) mm long. Axes usually denuded basally, 1–2(–3) mm in diameter below, tapering gradually to 200–400 µm in diameter near apices. Holdfast fibrous, 2–10 mm across; epilithic or epiphytic. Structure. Apical cells hemispherical, 8–10 µm in diameter, producing 4 pericentral cells and determinate branches close to apices, spirally arranged. Cortication of indeterminate branches commences close to apices, the pericentral cells remaining conspicuous in section, outer cortical cells irregularly elongate, L/D 2–4. Determinate laterals first simple, 1–2 mm long, soon branched from near their base, lesser branches 0.2–1 mm long, 40–90 µm in diameter, tapering near their tips; segments L/D (0.5–)0.8–2. Trichoblasts mainly on branches of determinate tufts, 0.2–1 mm long, branched, soon caducous, with scar cells on each segment in a one quarter spiral. Cells mostly uninucleate; rhodoplasts discoid to elongate.
Reproduction. Gametophytes dioecious. Procarps on trichoblasts on determinate lateral branches, with a pre-fertilization pericarp. Carposporophytes with a small basal fusion cell and short gonimoblast filaments bearing elongate-ovoid terminal carposporangia 45–75 µm in diameter. Cystocarps usually urceolate with a short neck and a distinct short basal stalk, 500–750 µm in diameter; pericarp ostiolate, 2 cells thick, outer cells isodiametric and angular. Spermatangial branches replacing trichoblasts, with a sterile basal cell, elongate-ovoid, 90–180 µm long and 25–70 µm in diameter. Tetrasporangia in branches of the determinate tufts, few to a series per branch, single per segment and bulging the segments, 75–110 µm in diameter.
Distribution.Albany, W. Aust., to Walkerville, Vic., and around Tas.
[After Womersley, Mar. Benthic Fl. Southern Australia IIID: 225–227 (2003)]