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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.

Herposiphonia pacifica Hollenb.

Reference
Pacific Sci. 22:549, Fig. 25 (1968)
Conservation Code
Not threatened
Naturalised Status
Native to Western Australia
Name Status
Current

Scientific Description

Habit and structure. Thallus red, attached by unbranched unicellular rhizoids, with digitate tips arising from the distal end of ventral pericentral cells. Indeterminate prostrate axes with circinate apices, with indeterminate axes arising laterally on alternate sides every 3 or 4 segments. Determinate lateral branches arising dorsally every 3 or 4 segments, 1 segment proximal to the indeterminate lateral branch. Prostrate axes terete, 130–145 µm diam. [segment L:B c. 1], with 11 or 12 pericentral cells. Determinate branches initially curved but becoming straight, unbranched, 2.6–3.4 mm and 11 or 12 segments long when mature, terete, 80–100 µm diam. [segment L:B mostly 1–1.5], with 14 or 15 pericentral cells, these noticeably narrower than the axial cell. Determinate axes with well-developed apical trichoblasts to 1.6 mm long, dichotomously divided to 7 times. Cells with plastids not transversely aligned.

Distribution. Widespread in the Indian and Pacific Oceans.

Habitat. Epilithic in the subtidal.

[After J.M. Huisman in Algae of Australia: Marine Benthic Algae of North-western Australia, 2. Red Algae: 517 (2018)]

John Huisman & Olga Nazarova, 3 August 2021

Distribution

IMCRA Regions
Shark Bay.
Local Government Areas (LGAs)
Carnarvon.