Acarospora fuscata

Ascomycota › Lecanoromycetes › Acarosporales › Acarosporaceae › Acarospora

Description

A brown crustose lichen made of adjoining, irregular areoles, often with dark edges. Small reddish-brown to nearly black apothecia are embedded in the areoles; several may occur within one areole.

Source: ITALIC — Acarospora fuscata

Chemistry

Cortex: K−, C+ red, KC+ red, P−, UV−. Gyrophoric acid is reported in the cortex; the medulla is C− and KC−.

Source: ITALIC — Acarospora fuscata

Habitat and Substrate

Grows mainly on acidic siliceous rock exposed to rain, sometimes spreading over other lichens.

Source: ITALIC — Acarospora fuscata

Similar Species

Compare other brown Acarospora species. The cortical C+ red reaction is useful, but identification also requires attention to thallus structure and apothecial anatomy.

Sources: ITALIC; BLS identification revision

How to Identify

Use the Acarospora key; check the cortical C reaction and a thin apothecial section.

Source: BLS identification revision

Important Links

ITALIC — description, chemistry and images

British Lichen Society — species account and British distribution

GBIF — taxonomy and global occurrence records

AFL — species account and photographs

Lichens maritimes — species photographs

Identification Bibliography

Knudsen, K., et al. (2021). Acarosporales: Acarosporaceae. Revisions of British and Irish Lichens, 12, 1–25.

Nimis, P. L., et al. ITALIC: The Information System on Italian Lichens. Online account: Acarospora fuscata.

For identification, use the relevant key and compare the microscopic characters and chemical reactions. Photographs alone may be insufficient for closely similar crustose species.