The species occurs on siliceous rock in full sun, often on small rocks and pebbles, throughout Europe and North America. It is apparently rare in the Czech Republic, so far reported from single localities mostly in Central Bohemia and Southern Moravia. It forms pseudo-lecanorine apothecia, the disc expanding until it reduces the areole to a thalline margin. The diagnostic character is large ascospores mostly 10–14 × 6.5–8.0 µm. Though it usually occurs on siliceous rock, or on siliceous rock inter mixed with calcareous rock, it can occur on calcareous substrates. Specimens on calcareous rock differ from A. macrocarpa in having an areolate thallus of pseudo-lecanorine apothecia and having less than 50 ascospores per ascus. The hymenium height is in Czech specimens as high as 140 µm.
taxonomic classification:Ascomycota → Lecanoromycetes → Acarosporales → Acarosporaceae → Acarospora
Red List (Liška & Palice 2010):DD – data deficient
Red List (Malíček 2023):C2 – strongly endangered
Occurrence in the Czech Republic
All records: 10, confirmed 9. One click on a selected square displays particular record(s), including their source(s).