Thallus crustose, membranaceous to gra-nulose or verrucose, white to gray-white; hypothallus lacking. Apothecia to 1 mm broad; exciple brown-black, entire to disappearing; disk black, flat to convex; hypothecium brown-black; epithecium brown; hymenium hyaline, 1+ blue, not inspersed, 70-100 µm; paraphyses brown-capitate; spores dark brown, 3-septate, often curved, 15-43 X 6-12 µm.
Reactions: thallus K+ yellow, P—.
Contents: atranorin in GAo-T test.
This species grows on moss and over other lichens. It appears to be circumpolar arctic and alpine.