Erythrotrichia carnea (Dillwyn) J.Agardh

Scientific Description

Habit and structure. Thallus rose-red, of simple, erect, axes, 1–8 mm high, arising from single, lobed, basal cells or a lax multicellular disc; usually epiphytic. Erect filaments at first uniseriate, often becoming 2–4 cells thick, cylindrical, cell divisions diffuse, 6–8 µm in diameter with cells L/B 2–4 near the base, 10–16(–20) µm in diameter above with cells L/B (0.5–)1–1.5(–2), and where 2–4 cells thick then 20–35 µm in diameter with cells isodiametric and 8–12 µm across. Cells with thick gelatinous walls and a single stellate rhodoplast with a central pyrenoid.

Reproduction. By monosporangia cut off from vegetative cells by a curved wall. Sexual reproduction by 3-celled monoecious gametophytes, with the apical cell producing first a spermatium, then becoming a carpogonium, the zygote then developing a diploid filament surmounting the gametophyte.

Distribution. Cosmopolitan.

Habitat. Epiphytic on larger algae.

[After Womersley, Mar. Benthic Fl. Southern Australia IIIA: 28 (1994)]