Buellia badia (Fr.) A. Massal.

Buellia with conspicuous, dark brown, thickly areolate to squamulose thallus and black apothecia between areoles. The species is predominantly lichenicolous, forming characteristic isles on thalli of various crustose lichens, such as members of the genus Xanthoparmelia. Older specimens often become solitary. Buellia badia grows on acidic to slightly calcareous, sunny siliceous and volcanic stones and rocks. It also infrequently occurs in cushions of small acrocarpous mosses on siliceous substrates. In the Czech Republic, the lichen is locally abundant mainly in river valleys at lower and middle elevations. The species is widespread in most of Europe, from lowlands to mountains but avoids alpine zones.

Ascomycota → Lecanoromycetes → Caliciales → Caliciaceae → Buellia