- Reference
- Phycologia 238 (1993)
- Conservation Code
- Not threatened
- Naturalised Status
- Native to Western Australia
- Name Status
- Current
Scientific Description
Habit and structure. Thallus medium to dark red or red-purple, often bleached to yellow-brown, surface usually slightly lustrous when dry, erect to decumbent, (5–)15–40(–60) cm high, relatively thin, foliose and ovate-lanceolate or with several broadly ligulate fronds mostly 2–10 cm broad, often with marginal proliferations 5–20 mm broad and 1–4 cm long, margin entire, apices usually tapering, arising from a slender, compressed stipe, cuneate above. Holdfast small, discoid, 1–2 mm across; epilithic. Structure of a compact cortex of subdichotomous anticlinal filaments, the outer cells 1–2 µm in diameter and L/D (1–)2–4, and a medulla of slender anastomosing filaments.
Reproduction. Sexual thalli monoecious. Carpogonial branches 3-celled, borne on inner cortical (supporting) cells which also bear 1–2 sterile cortical branches. Auxiliary cell derived from the supporting cell, developing the carposporophyte from numerous gonimoblast filaments which cut off laterally small groups of carposporangia (10–18 µm in diameter), with distinct filamentous enveloping tissue which forms a translucent zone around the dark red carposporophyte; mature cystocarps globose, 2–3 mm in diameter, scattered and slightly protruding; ostiole absent. Spermatangia in inconspicuous, irregular, scattered sori, cut off from surface cortical cells. Tetrasporangial sori maculate, 0.5–1 mm in diameter, situated just within the cortex and outer medulla, with the outer surface more or less level with the cortical surface, with rows of tetrasporangia radiating inwards from the surface, the outer 2–3 cells sterile, tetrasporangia 30–40 µm in diameter, cruciately divided.
Distribution. New Zealand (Wellington to Auckland I). Hamelin Bay, W. Aust., and Stenhouse Bay, S. Aust., to San Remo, Vic., and around Tas.
Habitat. In the lower eulittoral and upper sublittoral under slight to moderate wave action.
[After Womersley, Mar. Benthic Fl. Southern Australia IIIA: 287–289 (1994)]