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Service Notice

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 Conservation listings displayed on Florabase may also be out of date.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.

The notice period started at 12:00 pm on Wednesday, 1 October 2025 +08:00 and will end at 12:00 pm on Friday, 1 January 2027 +08:00.

Microdictyon umbilicatum (Velley) Zanardini

Reference
Mem.Reale Ist.Veneto Sci. 10:461, Pl. 19 (1862)
Conservation Code
Not threatened
Naturalised Status
Native to Western Australia
Name Status
Current

Scientific Description

Habit and structure. Thallus medium to dark grey-green, 10–30(–45) cm across, firm but delicate, irregularly lobed and lacerate, with an obscure umbilicate base, probably usually epiphytic. Blade essentially monostromatic but with occasional tertiary branches displaced to one side of an earlier branch; branching of filaments alternate, opposite, or with up to six secondary filaments radiating from one point. Primary filaments 180–220 µm in diameter, cells L/B 1.5–3; secondary filaments 80–140 µm in diameter, L/B 2–4, with a rounded tip when free; attachment of filaments by smooth adherence of un-modified ultimate segments; meshes of net irregular; division of segments by ingrowth from the peripheral wall; chloroplast reticulate, composed of numerous, round, pyrenoid-bearing areas with narrow connections.

Reproduction. Unknown.

Distribution. Rottnest I., and Cape Riche, W. Aust., and from Coobowie, Yorke Pen, to Victor Harbor, and American River Inlet, Kangaroo I., S. Aust., Port Jackson, N.S.W. and Southport, Qld.

Habitat. Usually in calm bays and inlets.

[After Womersley, Mar. Benthic Fl. Southern Australia I: 217 (1984)]

John Huisman & Cheryl Parker, 3 August 2021

Distribution

IMCRA Regions
Abrolhos Islands, Central West Coast, Leeuwin-Naturaliste, Ningaloo, Zuytdorp.
Local Government Areas (LGAs)
Carnarvon, Cockburn, Coorow, Exmouth, Greater Geraldton, Northampton.