- Reference
- Taxon 143 (1957)
- Conservation Code
- Not threatened
- Naturalised Status
- Native to Western Australia
- Name Status
- Current
Scientific Description
Habit and structure. Thallus dark red-brown, 10–30 cm high, with a short terete to compressed stipe producing several axes. Axes complanately branched, (2–)4–5 mm broad and 0.8–1.2 mm thick, bearing crowded, slender, marginal, pinnate branches, becoming denuded below but often proliferous from the margins. Pinnae (2–)4–12 cm long, 1–2 mm broad, bearing distichous and subopposite pinnules 1–3 cm long and 0.5–1(–1.5) mm broad, subterete to compressed, sometimes similarly branched. Holdfast robust, discoid, crustose, 0.5–3 cm across; epilithic. Structure multiaxial, developing a dense medulla of irregular longitudinal filaments, with rhizoids, and a pseudoparenchymatous cortex 4–5 cells thick, inner cells ovoid, 15–40(–50) µm in diameter, decreasing to the outer cells 3–5 µm in diameter. Rhodoplasts discoid, several to many per cell.
Reproduction. Sexual thalli dioecious; non-procarpic. Carpogonial branches 3-celled, borne on inner cortical cells, inwardly directed with reflexed trichogynes, often with a sterile cell on the basal cell. Connecting filaments 3–5, unbranched and non-septate. Auxiliary cells inner cortical cells, with adjacent cells becoming darker staining after diploidization, first developing gonimoblast initials inwardly and later radially from the fusion cell which develops a stalk of fused medullary cells; carposporangia in short chains, ovoid, 5–8 µm in diameter. Cystocarps often adjacent, bulging near the pinnule edge, with slight enveloping tissue, ostiolate. Spermatangia scattered on young branches, cut off from outer cortical cells often with interspersed sterile cells, ovoid, 2–3 µm in diameter. Tetrasporangia scattered in the outer cortex near branch ends, among elongate sterile cells, basally attached, elongate-ovoid, 15–25 µm long and 7–10 µm in diameter, zonately divided.
Distribution.Geraldton, W. Aust., to Seal Bay, Kangaroo I., and southern Yorke Pen, S. Aust.
[After Womersley, Mar. Benthic Fl. Southern Australia IIIA: 335–337 (1994)]
Distribution
- IBRA Regions
- Esperance Plains, Geraldton Sandplains, Jarrah Forest, Swan Coastal Plain, Warren.
- IBRA Subregions
- Geraldton Hills, Perth, Recherche, Southern Jarrah Forest, Warren.
- IMCRA Regions
- Abrolhos Islands, Central West Coast, Leeuwin-Naturaliste, WA South Coast.
- Local Government Areas (LGAs)
- Augusta Margaret River, Busselton, Cambridge, Cockburn, Coorow, Dandaragan, Esperance, Greater Geraldton, Irwin, Mandurah, Northampton, Rockingham.