- Reference
- Cryptog.Algol. 19:195 (1998)
- Conservation Code
- Not threatened
- Naturalised Status
- Native to Western Australia
- Name Status
- Current
Scientific Description
Habit and structure. Thallus dark brown-red, robust, firm, cartilaginous, (2–)10–15 cm high, with one to several axes, little-branched when young, becoming much-branched radially for 2–3 orders and pyramidal in form when mature; branches terete, axes (1–)1.5–2(–3.5) mm in diameter, slightly tapering basally, lesser branches 1.5–2.5 mm in diameter. Holdfast discoid, thin, 2–10 mm across; epilithic. Structure. Epidermal cells 12–20 µm across, isodiametric to slightly elongate, compact, scarcely elongating below, without secondary pit-connections or corps en cerise; in section, epidermal cells elongate and palisade-like, L/D 1.5–2.5, cortical cells compact, without lenticular thickenings. Cells with elongate rhodoplasts, ribbon-like and reticulate in cortical cells.
Reproduction. Gametophytes dioecious. Procarps not observed. Carposporophytes with a basal fusion cell and branched gonimoblast bearing clavate terminal carposporangia 20–40 µm in diameter. Cystocarps largely immersed, forming slight to hemispherical mounds on lesser branches, 0.7–1 mm across; pericarp ostiolate, several cells thick near ostiole. Spermatangial ramuli short, papillate to cushion-shaped on the branchlets, with inflated receptacles 1.5–2(–2.5) mm across, spermatangia borne on trichoblasts. Tetrasporangia in short verrucose papillae, appearing clustered in cavities corresponding to the apices of very short ramuli, cut off abaxially, in right-angle arrangement, 75–120 µm in diameter.
Distribution.Elliston, S. Aust., to San Remo, Vic, and around Tas.
Habitat. C. tumidus is a distinctive species occurring near to low tide level on coasts of moderate roughness.
[After Womersley, Mar. Benthic Fl. Southern Australia IIID: 485–489 (2003)]