- Reference
- Schmitz & Falkenberg, Nat.Pflanzenfam. [Engler & Prantl] I(2):464 (1897)
- Conservation Code
- Not threatened
- Naturalised Status
- Native to Western Australia
- Name Status
- Current
Scientific Description
Habit and structure. Thallus dark red-brown, 2–10 mm long, prostrate on and adherent to the host, complanately branched with occasionally branched compressed axes, with paired determinate laterals from adjacent segments on alternate sides, the anterior of each pair 250–600 µm long, flexed forward from the axial cell and branched as in the axes but of limited development, the posterior one simple, emitted directly from the axial cell, and 100–200 µm long. Lateral branches of axes occur by continued growth of the anterior determinate lateral. Attachment by rhizoids; epiphytic on various algae. Structure. Apical cells hemispherical, 10–15 µm in diameter. Axes with 5–6 pericentral cells (3–4 in face view), terete determinate laterals with 5(–6) pericentral cells, axial segments L/D 0.5–0.8. Trichoblasts occur on end segments of determinate laterals or their branches, 200–1000 µm long, much branched with basal cells 15–25 µm in diameter and L/D 1–2, upper cells longer and slenderer. Rhizoids cut off from lateral pericentral cells of axes, unicellular with multicellular haptera. Cells uninucleate; rhodoplasts discoid, chained in larger cells.
Reproduction. Gametophytes monoecious, probably also dioecious. Procarps probably on basal cell of trichoblasts on determinate laterals, rapidly polysiphonous. Carposporophytes with a small basal fusion cell and short, branched, gonimoblast with clavate terminal carposporangia 10–18 µm in diameter. Cystocarps ovoid to slightly urceolate, 200–300 µm in diameter; pericarp ostiolate, 2 cells thick, ecorticate, outer cells angular, L/D about 1(–2). Spermatangial organs lanceoid, 80–180 µm long and 35–55 µm in diameter, with 1(–2) basal sterile cells and 2–3 sterile apical cells. Stichidia developed from determinate laterals, curved, free from host and more-or-less erect, with tetrasporangia in a fairly straight row, 30–45 µm in diameter, with 2 cover cells.
Distribution.In southern Australia, from Yanchep, W. Aust., to Phillip I., Vic., and N Tas. N.S.W. Widespread in the temperate southern hemisphere, extending into the northern hemisphere.
[After Womersley, Mar. Benthic Fl. Southern Australia IIID: 304–306 (2003)]