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Service Notice

The Western Australian Herbarium’s collections management system, WAHerb, and DBCA’s taxonomic names application, WACensus, have been set to read-only mode since 1 October 2025. Recent taxonomic changes are not reflected in Florabase, herbarium collections, or in the census. We are hoping to be able to reinstate services around December 15; we will provide an update at that time.

The notice period started at 9:00 am on Wednesday, 1 October 2025 +08:00 and will end at 12:00 pm on Monday, 15 December 2025 +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.