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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.

Actinotrichia fragilis (Forssk.) Børgesen

Reference
Dansk Bot.Ark. 8:6, Pl. 1, Fig. 4 (1932)
Conservation Code
Not threatened
Naturalised Status
Native to Western Australia
Name Status
Current
Image

Scientific Description

Habit and structure. Thallus to 7 cm high, grey-pink to orange-red, forming a hemispherical or spreading clump, subdichotomously branched at intervals of 2–10 mm. Axes 250–600 µm in diameter; emergent filaments either absent, randomly arranged, or in whorls at intervals of 150–200 µm. Medullary filaments 5–12 µm in diameter. Cortex 3 or 4 cells thick; inner cells 22–32 µm in diameter, with occasional lateral fusions; epidermal cells turbinate, 20–27 µm in diameter; emergent filaments cylindrical, to 550 µm long, with cells 10–13 µm in diameter.

Reproduction. Spermatangial cavities 150–250 µm in diameter; spermatangia spherical to obovoid, c. 5 × 7 µm. Cystocarps not observed. Tetrasporangia subspherical, 25–27 × 22–25 µm.

Distribution. Known from Coral Bay, W.Aust., presumably across northern Australia to the Great Barrier Reef, Qld. Widespread in tropical seas.

Habitat. A. fragilis growson rock or coral platforms in the subtidal.

John Huisman & Cheryl Parker, 3 August 2021

Distribution

IBRA Regions
Carnarvon, Dampierland, Northern Kimberley.
IBRA Subregions
Cape Range, Mitchell, Pindanland.
IMCRA Regions
Kimberley, Ningaloo, Pilbara (offshore).
Local Government Areas (LGAs)
Ashburton, Broome, Carnarvon, Derby-West Kimberley, Exmouth, Karratha, Wyndham-East Kimberley.