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Service Notice

The Western Australian Herbarium’s collections management system, WAHerb, and DBCA’s flora taxonomic names application, WACensus, have been set to read-only mode since 1 October 2025. Recent taxonomic changes are not currently being reflected in Florabase, herbarium collections, or the census. Due to the rapidly approaching holiday season and associated agency and facility soft closures, along with the substantial work involved in data mapping, cleaning, and verification, the migration to the new collection management software is not expected to occur before 1 March 2026, when a further update will be provided. Please reach out to us if you have any questions or concerns.

The notice period started at 9:45 am on Friday, 12 December 2025 +08:00 and will end at 12:00 pm on Monday, 2 March 2026 +08:00.

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)]