- Reference
- J.Phycol. 224 (2002)
- Conservation Code
- Not threatened
- Naturalised Status
- Native to Western Australia
- Name Status
- Current
Scientific Description
Habit and structure. Thallus dark brown, drying almost black, 5–15(–25) cm high, cartilaginous, usually much branched for 3–4 orders from the midrib or proliferous from eroded apices, branches linear, flat, tapering basally and with rounded, recurved, apices, (2–)3–5 mm broad and 240–300 µm thick, margins smooth, thickened, midrib inconspicuous, branch surfaces without proliferations. Holdfast discoid to crustose, 2–20 mm across; epilithic, just below low tide level or in deeper water. Structure. Apices rounded, recurved, apical cells within the recurved apices, conical, 15–20 µm in diameter, blade margins thickened. Apical cells cutting off probably 5 pericentral cells, with 2–4 pseudopericentral cells, forming an irregular medulla 1–3(–4) cells broad (the central cells largest) and a cortex 1–2 cells broad; secondary cortex formed over the midrib on older branches. Trichoblasts only associated with reproductive organs, reduced. Cells probably uninucleate; rhodoplasts discoid, chained in larger cells.
Reproduction. Reproductive organs borne on short, erect shoots over the midrib, rarely elsewhere. Gametophytes dioecious. Procarps formed in series on trichoblasts on polysiphonous branchlets on midribs. Carposporophytes with a basal fusion cell and much branched gonimoblast with clavate terminal carposporangia 20–55 µm in diameter. Cystocarps stalked, ovoid, 700–1000 µm in diameter; pericarp ostiolate, corticated, 4–5 cells thick. Spermatangial organs on polysiphonous, simple or branched, erect shoots from a hemispherical base, ovoid, 70–110 µm in diameter, with a sterile basal cell and 3–5 fertile axial cells. Stichidia (2–8) on proliferous shoots on the midrib, 0.5–1(–4) mm long and 120–180 µm broad, compressed, corticated, sometimes with reduced trichoblasts, tetrasporangia in 2 rows, 50–80 µm in diameter.
Distribution.Yallingup, W. Aust., to Walkerville, Vic., and around Tas; Twofold Bay, N.S.W.
Habitat. E. proliferum is a common species on rough-water platforms, often forming dense tufts just below low tide level; it also occurs to about 10 m deep.
[After Womersley, Mar. Benthic Fl. Southern Australia IIID: 403–404 (2003)]