Chauviniella coriifolia (Harv.) Papenf.

Scientific Description

Habit and structure. Thallus medium to dark red, 10–30 cm high, much branched from the midrib with flat, more-or-less linear branches 2–8 cm long and 4–12 mm broad, with obtuse apices; blades 100–200 µm thick. Axes and lower branches becoming heavily corticated, stipes compressed to subterete, 1–3 mm across. Holdfast discoid, becoming fibrous, 2–10 mm across; epilithic. Structure. Apical cells dome-shaped, segmenting to produce first 2 lateral pericentral cells then 2 transverse pericentral cells, the lateral cells producing second-order cell rows (sometimes visible as faint veins) with each cell producing a third-order row, all of which reach the blade margin. Cortication of the midrib and blades commencing early, becoming 2–3 cells thick, cells irregularly placed with larger and smaller cells and rhizoids, outer cells more-or-less isodiametric, 4–6 µm across; stipes pseudoparenchymatous, cells and rhizoids intermixed. Cells multinucleate; rhodoplasts discoid.

Reproduction. Reproductive organs borne in small clustered bladelets arising on the midrib. Gametophytes dioecious. Procarps formed on successive transverse pericentral cells on one side of blades, each with 2 sterile groups and a 4-celled carpogonial branch. Carposporophytes with a basal network of separated cells and surrounded by a lesser network of elongate, mostly anticlinal, cells which extend to the surface of the blade around the ostiole; this lesser network is surrounded by a conspicuous space as seen in sectional view; carposporophytes themselves little branched, with a basal fusion cell and few carposporangia. Cystocarps sunken within the swollen blade, ovoid, with a pericarp several cells thick (such cystocarps doubtfully mature). Spermatangia not observed. Tetrasporangial sori round to ovate, covering most of small proliferous bladelets, cortex 3–4 cells thick, tetrasporangia cut off from mid cortical cells, with an outer cortical layer of small cells; tetrasporangia subspherical, 45–65 µm in diameter.

Distribution.Port Denison, W. Aust., to Port Fairy, Vic.

[After Womersley, Mar. Benthic Fl. Southern Australia IIID: 59–63 (2003)]