Dasya parsonsii Huisman

Scientific Description

Habit and structure. Thallus to 37 cm tall, light pink to dark red, irregularly branched, with somewhat sinuous axes. Primary axes corticated to near the apices, bearing a dense cover of pseudolateral branches and adventitious monosiphonous filaments over most of the thallus. Pseudolaterals arising on each segment, subdichotomously divided several times near base, then with lengthy terminal branches. Intercalary divisions rare to common. Pseudolateral cells to 15–20 μm diam. [L:B 1–6].

Reproduction. Spermatangial stichidia initially terminal on monosiphonous filaments, with 10–14 fertile segments, becoming intercalary due to growth of the primary filament, this extending for up to 50 cells. Tetrasporangial stichidia borne on monosiphonous filaments, with up to 13 fertile segments, each with 5 tetrasporangia with 2 or 3 post-sporangial cover cells, these cuboidal, often with L:B <1, and only slightly covering the tetrasporangia. Tetrasporangia spherical, tetrahedrally divided, 30–40 μm diam.

Distribution. Known only from Barrow Island, north-western Australia.

Habitat. Epilithic in the shallow subtidal and intertidal pools.

[After J.M. Huisman in Algae of Australia: Marine Benthic Algae of North-western Australia, 2. Red Algae: 433–434 (2018)]