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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.

Platythalia angustifolia Sond.

Reference
Bot.Zeit. 51 (1845)
Conservation Code
Not threatened
Naturalised Status
Native to Western Australia
Name Status
Current
Image

Scientific Description

Habit and structure. Thallus dark brown, 20–80 cm long, with several complanately branched axes from the holdfast. Holdfast discoid-conical, soon becoming irregularly stoloniferous, 1–3 cm across; epilithic. Axes compressed, alternately pinnately branched, slightly flexuous, becoming denuded and relatively straight below, (2–)3–4(–5) mm broad and (0.5–)1–2 mm thick, with laterals 0.5–1 cm apart. Laterals simple to alternately pinnate, 1.5–4 cm long and (1–)2–3(–4) mm broad, basally constricted, entire, linear to lanceolate, with a slight costa. Medulla of elongate cells with few hyphae, and a cortex of isodiametric cells with a surface phaeoplastic meristoderm.

Reproduction. Thalli dioecious. Receptacles developed from branches of upper laterals, simple or branched. (1–)2–4 cm long and (1–)1.5–3(–4) mm broad. Conceptacles in two rows with marginal or submarginal ostioles, unisexual; oogonia sessile, ovoid, 120–180 µm long and 60–100 µm in diameter, with simple paraphyses; antheridia sessile or on branched paraphyses, ovoid, 25–30 µm long and 10–15 µm in diameter.

Distribution. From Flat Rocks, 40 km S of Geraldton, to Cape Riche, W. Aust.

[After Womersley, Mar. Benthic Fl. Southern Australia II: 404–406 (1987)]

John Huisman & Cheryl Parker, 3 August 2021

Distribution

IBRA Regions
Esperance Plains, Jarrah Forest, Swan Coastal Plain, Warren.
IBRA Subregions
Perth, Recherche, Southern Jarrah Forest, Warren.
IMCRA Regions
Central West Coast, Leeuwin-Naturaliste, WA South Coast.
Local Government Areas (LGAs)
Albany, Augusta Margaret River, Bunbury, Busselton, Cockburn, Cottesloe, Dandaragan, Denmark, Esperance, Irwin, Mandurah, Manjimup.