Cliftonaea pectinata (Harv.) Harv.

Scientific Description

Habit and structure. Thallus medium to dark red-brown, 10–20 cm tall, richly but irregularly branched; branches with revolute apices, with a dorsal membranous axial keel 0.5–2.0 mm wide, opposite the keel bearing terete pectinate determinate laterals 2–4 mm long, closely arranged in 2 slightly divergent rows, alternating from successive segments. Holdfast discoid, bearing several axes; epilithic. Apices revolute ventrally (on the side of the determinate laterals); apical cells dome-shaped, 15–20 µm diam.; axial cells cutting off 6 pericentral cells with dorsal and ventral cells and 2 lateral ones on each side, the dorsal cells dividing longitudinally to form the keel; the 2 ventral lateral cells forming the determinate laterals from alternate segments. Keel 1 cell thick and 6–12 cells wide; cells 30–60 µm diam. [L:B 3–4]. Determinate laterals 120–180 µm diam., with 3 pericentral cells [segment L:B 0.6–1.3]. Branching endogenous from the axial cells, emitted laterally from near the keel. Trichoblasts adaxial on each segment of the determinate laterals, 1–2 mm long, branched; basal cells 15–20 µm diam. [L:B 2–3]. Cells multinucleate; rhodoplasts discoid to elongate, chained in larger cells.

Reproduction. As for genus.

Distribution. Known from the Montebello Islands, Western Australia, around south-western and southern Australia to Port Phillip Heads, Victoria.

[After J.M. Huisman in Algae of Australia: Marine Benthic Algae of North-western Australia, 2. Red Algae: 502–503 (2018); J.M. Huisman in Marine Plants of Australia: 212 (2019)]