Bangia atropurpurea (Roth) C.Agardh

Scientific Description

Habit and structure. Thallus rose to dark red, occurring as a dense mass of flaccid, simple filaments, 1–10 cm long and 20–200(–300) µm in diameter, with a prominent mucilaginous sheath, each filament basally attached by rhizoids from several suprabasal cells. Filaments at first uniseriate, becoming several cells broad by longitudinal divisions producing radially elongate, cuneate, cells surrounding a slight central cavity. Cells in uniseriate filaments 8–16(–20) µm in diameter and L/D (0.2–)0.5–1.5, in thicker parts isodiametric in surface view, 8–12 µm across, each with a single stellate rhodoplast with a central pyrenoid. Conchocelis-phase as for the genus, not recorded for Australian plants.

Reproduction. By monospores liberated from vegetative cells. Sexual plants dioecious; carpogonia with a slight prototrichogyne; carposporangia formed in vague groups of 8–16; spermatangia formed in more-or-less square (in surface view) packets of 16–64, pale in colour, with spermatia 2–3 µm in diameter.

Distribution. In southern Australia, from Fremantle, W. Aust., around Tas., to N.S.W, and southern Qld.

Habitat. Grows on marine mid eulittoral rock or timber.

[After Womersley, Mar. Benthic Fl. Southern Australia IIIA: 34–36 (1994)]