Champia pseudoparvula Huisman & G.W.Saunders

Scientific Description

Habit and structure. Thallus sprawling, to 8 cm long, red to light brown, attached to the substratum by several discoid holdfasts and often with several secondary attachments. Axes terete, to 1.0–1.5 mm diam., with slight constrictions at the level of diaphragms, forming barrel-shaped segments [L:B 1.0–1.5], occasionally to frequently radially branched from constrictions. Outer cellular tissue with 1–3 layers, in surface view with an inner layer of large, generally longitudinally elongate cells, 60–100 µm long, 35–70 µm broad, bearing outwardly smaller, more pigmented cells, these occasionally in prominent or loose rosettes. Vesicular cells common in the outer layer, these outwardly bearing a hair up to 300 µm long with a slightly inflated tip. Longitudinal filaments along inner surface of peripheral layer, 7–10 µm diam., with 1 or 2 complete cells between diaphragms, centrally bearing inwardly directed spherical, obovoid or pyriform vesicular cells 12–17 µm long and 10–20 µm diam. Diaphragms almost transparent, with a single thin cell layer, composed of cells 70–145 µm broad.

Reproduction. Spermatangia in sori covering large portions of thallus surface, arising in candelabra-like clusters. Cystocarps solitary or several per segment, hemispherical, 700–900 µm diam. Tetrasporangia subspherical, 55–75 µm diam.

Distribution. Known from Coral Bay north to Cassini Island, Western Australia.

Habitat. Epilithic or epiphytic in the intertidal and subtidal.

[After J.M. Huisman in Algae of Australia: Marine Benthic Algae of North-western Australia, 2. Red Algae: 309–311 (2018)]