Sarcogyne regularis

Taxon

Sarcogyne regularis

Authority
Körb. (1855)
Synonyms
Sarcogyne pruinosa
Conservation Status
BLS Number
1306
Taxon Photo
General Description

A pioneer species of calcareous substrates, natural and anthropogenic, frequent in lowland areas. The dark apothecia discs are generally densely blue-grey pruinose but look red-brown when wet. Internally the multispored asci with about 100 to 200 spores are distinctive.

Identification

Thallus generally immersed and inconspicuous, or white to grey and scurfy. Apothecia sessile or ± sunken into pits in the substrate, (0.3–) 0.4–1.5 (–2) mm diam.; disc red-brown to black, generally densely blue-grey pruinose but sometimes not; exciple black, often more densely pruinose than the disc and then white-grey, not or slightly raised, not crenulate, finally becoming excluded, to 50 μm thick; hymenium (65–) 70–100 (–110) μm tall; hypothecium ± colourless. Asci 60–85 × 14–18 μm, 100- to 200-spored. Ascospores 3–5 (–6) × 1.5–2 μm. Conidiomata unknown.

Morphs with red-brown, densely pruinose apothecia embedded in pits in the substrate, usually hard limestones, are sometimes distinguished as a separate species, ‘S. pruinosa auct.’, the status and correct name of which remains unclear. Specimens lacking pruina are rare but occur.

Habitats

On calcareous rocks, walls, chalk pebbles, sea-shells, asbestos-cement and old mortar, particularly in lowland areas.

Distribution Map
Key to map date classes
Distribution

Frequent, throughout Britain and Ireland, less frequent in the uplands.

References

Knudsen, K., Kocourková, J., Cannon, P., Coppins, B., Fletcher, A. & Simkin, J. (2021). Acarosporales: Acarosporaceae, including the genera Acarospora, Caeruleum, Myriospora, Pleopsidium, Sarcogyne and Trimmatothelopsis. Revisions of British and Irish Lichens 12: 1-25.

Text by Neil A Sanderson, based on Knudsen et al (2021)