Dasya carteri Huisman

Scientific Description

Habit and structure. Thallus to 11 cm tall and 20 cm broad, dark red-brown, arising from a discoid holdfast, irregularly dichotomously branched. Axes to 3 mm broad, tapering to apices, heavily corticated and densely clothed with monosiphonous filaments to 3 mm long. Axial and periaxial cells obvious in section. Pseudolaterals and adventitious monosphonous laterals similar in form, 1–4 (–5) times subdichotomously branched near the base, with terminal filaments many-celled and to 2 mm long. Cells of monosiphonous filaments slightly broader at base (12–14 µm diam.), tapering for 3–5 cells, then distally with cells of similar diameter (8–12 µm), mostly relatively short [L:B 2.5–5], with rare intercalary divisions.

Reproduction. Tetrasporangial stichidia arising terminally or laterally on pseudolaterals, sessile or with a 1- or 2-celled pedicel, lanceolate, with up to 15 segments, each with 4 sporangia, with 2 (–3) cover cells cupping each sporangium, covering only a small portion. Tetrasporangia spherical, tetrahedrally divided, to 35–40 µm diam. Other reproductive structures not observed.

Distribution. Known only from the Noyon Reef, Western Australia.

Habitat. Epilithic in the intertidal.

[After J.M. Huisman in Algae of Australia: Marine Benthic Algae of North-western Australia, 2. Red Algae: 427–429 (2018)]