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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.

Porolithon pachydermum (Foslie) Foslie

This name is not current. Find out more information on related names.

Reference
Kongel.Norske Vidensk.Selsk.Skr. (Trondheim) 1909(2):57 (1909)
Conservation Code
Not threatened
Naturalised Status
Native to Western Australia
Name Status
Not Current

Scientific Description

Habit and structure. Thallus encrusting to lumpy, pale pink, 70–800 μm thick, monomerous in construction. Medulla multilayered, of branched filaments produced by apical initials 7–15 μm long, 9.5–15.0 μm diam.; lateral fusions uncommon; medullary cells 7–27 μm long, 7–12 μm diam. Cortex multilayered, with cells 7–20 μm long, 7–10 μm diam. Cortical filaments each ending in an intercalary initial cell that subtends 1 (rarely 2) rounded epithallial cells 7–8 μm long, 7–10 μm diam., with centrally placed cytoplasm. Intercalary initials generally a similar size to the cortical cells that they generate. Megacyte fields throughout the uppermost cortical layers, obvious from the surface, also evident deeper in the cortex, formed from modified cortical cells 29–40 μm long, 12–20 μm diam.; as fields mature, the megacytes appear to slough, leaving an open ‘honeycomb’. Megacyte fields becoming buried in the cortex, their appearance unchanged.

Reproduction. Tetrasporangial conceptacles level with the thallus surface, with only the pore visible, 65–220 μm outside diam., 165–390 μm internal diam.; pore 10–20 μm diam. below the conceptacle roof. Mature conceptacles becoming buried in the cortex. Tetrasporangia 40–60 μm long, 20–28 μm diam. Other reproductive structures not observed.

Distribution. Restricted to tropical waters of Pacific Ocean and Caribbean Sea.

Habitat. epilithic in the intertidal.

[After R.A. Townsend & J.M. Huisman in Algae of Australia: Marine Benthic Algae of North-western Australia, 2. Red Algae: 125 (2018)]