Chondria fusifolia (Hook.f. & Harv.) Harv.

Scientific Description

Habit and structure. Thallus light to medium red-brown, fading to yellow-brown, (3–)10–20(–30) cm high, usually fairly robust, much-branched irregularly radially for 3–4 orders, branches terete, with one to several axes (0.5–)1–1.5 mm in diameter, grading to lesser branches 2–5 mm long and (250–)400–800 µm in diameter, basally constricted. Holdfast discoid, 2–4 mm across; epilithic or epiphytic, usually in shallow water. Structure. Apices bluntly pointed, with 9–14 axial cells bearing pericentral cells and trichoblasts. Pericentral cells 5, producing outwardly 3–4 quadrichotomous series of cortical cells, epidermal cells becoming 10–25 µm in diameter and L/D 2–5(–12). Mature axes with large cortical cells and intermixed rhizoids. Cell wall thickenings usually absent, when present forming caps on pericentral cells. Trichoblasts 1–1.5 mm long. Cells with rhodoplasts discoid, chained in largest cells.

Reproduction. Gametophytes dioecious. Procarps on the suprabasal cell of trichoblasts, the fifth pericentral cell bearing a 4-celled carpogonial branch and lateral and basal sterile groups, each becoming multicellular. Carposporophyte with a basal, branched, fusion cell and branched gonimoblast bearing elongate-clavate terminal carposporangia 30–45 µm in diameter. Cystocarps ovoid to slightly urceolate, 500–900 µm in diameter, with a slight basal spur; pericarp ostiolate, with 12–16 erect filaments, each cell producing outwardly 2 pericentral cells with slight cortication on the lower half. Spermatangial plates formed from a basal branch of a trichoblast, discoid, 250–350 µm across, with smooth or irregular margins 2(–3) cells broad. Tetrasporangia occur in lesser branches, borne adaxially near the distal end of pericentral cells which remain radially elongate, 100–130 µm in diameter.

Distribution.Albany, W. Aust., to Pittwater, N.S.W., and around Tas.

[After Womersley, Mar. Benthic Fl. Southern Australia IIID: 438 (2003)]