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The Western Australian Herbarium’s collections management system and census were set to read-only mode on 1 October 2025. Taxonomic updates published since this time are not being reflected in Florabase, herbarium collections, or Western Australia’s taxonomic names census (Nomos). Conservation listings displayed on Florabase may also be out of date. Please refer to DBCA’s Threatened species and communities webpage for the most recent Threatened and Priority Flora List, noting that recent taxonomic updates are similarly not included. Our database migration is moving to a staging phase. We thank you for your patience as we ensure the integrity of our biodiversity data, develop new workflows, and train staff to use the new systems. Please reach out to us if you have any questions or concerns.

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Dictyota robusta J.Agardh

Reference
Analecta Algol. 1:76-77 (1894)
Conservation Code
Not threatened
Naturalised Status
Native to Western Australia
Name Status
Current
Image

Scientific Description

Habitat and structure. Thallus medium to dark brown, (5–)10–20 cm long, dichotomously branched at intervals of (1–)1.5–5 cm, branches (3–)5–15(–20) mm broad, usually increasing in width above points of branching, axils rounded, apices broad and usually truncate with a slightly depressed apical cell; proliferations absent except following damage. Holdfast rhizoidal; epilithic. Cortical cells 14–22 µm across, L/B1–1.5(–2). Medulla in upper and mid parts of thallus one cell thick centrally, 3–4 cells thick near the margins, in older parts becoming 2 cells thick centrally; thickness centrally 120–160 µm, becoming 200–240 µm thick below, margins 240–320 µm thick; intracellular wall thickenings present in medullary cells of some thalli. Hair tufts scattered, hairs 16–24 µm in diameter.

Reproduction.Unknown.

Distribution From the Houtman Abrolhos, W. Aust., to Port Phillip Heads, Vic.

Habitat. D. robusta is a deep water species off open coasts, known from 10 to 50 m deep.

[After Womersley, Mar. Benthic Fl. Southern Australia II: 202 (1987) as Dilophus robustus]

John Huisman & Cheryl Parker, 3 August 2021

Distribution

IBRA Regions
Esperance Plains, Geraldton Sandplains, Swan Coastal Plain.
IBRA Subregions
Geraldton Hills, Perth, Recherche.
IMCRA Regions
Abrolhos Islands, Central West Coast, Leeuwin-Naturaliste, WA South Coast.
Local Government Areas (LGAs)
Augusta Margaret River, Cockburn, Dandaragan, Esperance, Greater Geraldton, Irwin, Jerramungup.