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Polysiphonia homoia Setch. & N.L.Gardner

Reference
Proc.Calif.Acad.Sci. ser. 4, 19:162 (1930)
Conservation Code
Not threatened
Naturalised Status
Native to Western Australia
Name Status
Current

Scientific Description

Habit and structure. Thallus mostly upright, flaccid, to 8 mm tall, with limited prostrate axes attached to sand and other debris by rhizoids. Lateral branches associated with basal cells of trichoblasts, every 6–11 segments, basally slightly constricted. Lower axes to 400 µm diam. [segment L:B 0.9–1]; mid-thallus 170–200 µm diam. [segment L:B c. 1]; upper branches 35–55 µm diam. [segment L:B to 2]. Segments mostly with 5 pericentral cells, generally 6 in fertile tetrasporangial segments. Trichoblasts sparse to profuse, arising 1 per segment every 3–6 segments, eventually dehiscent and leaving scar cells, with a short basal cell and then often with a considerably broader suprabasal cell to 40 µm diam.

Reproduction. Tetrasporangia in linear series of up to 15 sporangia in upper branches, although only the proximal 4–7 sporangia appear mature, spherical to subspherical, 50–75 µm diam., slightly distending the bearing segment. Cystocarps when mature spherical, to 340 µm diam., with lachrymiform carposporangia 70–85 µm long, 25–30 µm diam.

Distribution. Recorded from various locations in the tropical Pacific. In north-western Australia known from the Pilbara region.

Habitat. epilithic in the subtidal.

[After J.M. Huisman in Algae of Australia: Marine Benthic Algae of North-western Australia, 2. Red Algae: 565–567 (2018)]