Myriodesma leptophyllum J.Agardh
Acta Univ.Lund. 6 (1890)

Conservation Code: Not threatened
Naturalised Status: Native to Western Australia
Name Status: Current

Scientific Description
John Huisman & Cheryl Parker, Thursday 8 September 2016

Habit and structure. Thallus medium to dark brown, 10–30 cm long, with 2–3 more or less complanately branched fronds from each branch of the stipe. Holdfast discoid-conical, 3–10 mm across; epilithic. Stipe 5–15 cm long, irregularly branched at intervals of 2–10 cm, each 1–3.5 mm in diameter, thickening by meristoderm activity. Fronds 3–20 cm long, pinnate becoming bipinnate, laterals sub-opposite below, alternate above, compressed, linear, entire, 0.5–1.5 mm broad; midrib absent or slight. Structure of fronds 300–400 µm and 10–15 cells thick, with a slight medulla of elongate cells and hyphae, and a cortex of isodiametric cells with an inactive surface meristoderm of short cells.

Reproduction. Thalli monoecious. Conceptacies in a single, occasionally double, irregular row on each side of the branches, bisexual, with a dense basal tuft of phaeophycean hairs; oogonia sessile, ovoid but broad-based, 100–120 µm long and 50–80 µm in diameter; antheridia sessile or on short, branched, paraphyses, ovoid, 20–30 µm long and 8–12 µm in diameter.

Distribution. From Israelite Bay, W. Aust., to Robe, S. Aust.

[After Womersley, Mar. Benthic Fl. Southern Australia II: 410 (1987)]