Balliella crouanioides (Itono) Itono & Tak.Tanaka

Scientific Description

Habit and structure. Thallus red, often with orange iridescent tips in situ, slightly mucilaginous, with a limited prostrate system and erect axes to 4 cm tall. Primary axes with indeterminate lateral branches arising every (1–) 2 (–5) cells, becoming densely corticated by filaments arising from basal cells of lateral branches. Axial cells near apices 10–15 µm diam. [L:B 2–3]; mid-thallus 20–40 µm diam. [L:B 2–4]; lower cells 60–145 µm diam. [L:B 5–8]. All cells with 1–3 spherical vesicular inclusions. Vesicular cells abaxial and occasionally adaxial on the basal cells of lateral branches, spherical, 5–12 µm diam. Carposporophytes generally arising in pairs, on opposite basal cells, the entire structure 430–550 µm wide, with an involucre of somewhat disordered filaments; each carposporophyte with 5 or 6 gonimolobes to 70–200 µm diam., composed of angular carposporangia 25–35 µm wide when mature.

Reproduction. Tetrasporangia mostly adaxial on basal cells of lateral branches, sometimes on suprabasal or other cells, often also on corticating filaments, sessile or occasionally with a stalk cell, ellipsoidal, 40–50 µm long, 25–35 µm diam., cruciate or decussate. Other reproductive structures not observed.

Distribution. Known from Kenya, Mozambique, South Africa, Taiwan, southern Japan, Korea and north-western Australia.

Habitat. Epilithic in the subtidal.

[After J.M. Huisman in Algae of Australia: Marine Benthic Algae of North-western Australia, 2. Red Algae: 379–380 (2018)]