Global occurrence: Eurasia – Europe | Americas – North America (incl Mexico) | Arctic. Substrate: rock, stones, pebbles – unspecified. Life habit: lichenized (mutualistic with algal photobionts). Thallus: crustose (crustaceous) – episubstratal – unspecified; thallus: cracked, fissured, fractured, rimose | compartimentized – areolate, squamulate; [th] upper surface: white(ish) | black(ish) green; [th marginal and upper surface] specific structures: absent. Ascomata: absent | present; ascoma: perithecial, perithecioid – hymenial; ascoma [mm]: (median) 1.0; ascoma: immersed, innate; [ascm, if apoth] margin excipular photobionts: absent; [ascm] paraphyses/-oids: absent. Asci: fissitunicate – verrucarialean; [asc] tholus: thickened; [asc] tholus amyloidity (iodine reaction): absent. Ascospores: (median) 8.0; [asp] shape: ellipsoidal; [asp] length [µm]: (low) 7.0 (high) 10.0; [asp] width [µm]: (low) 4.0 (high) 7.0; [asp] septa: absent – spore lumen unilocular, monolocular; [asp] pigmentation: hyaline, colourless; [asp] perispore, epispore: not apparent. Secondary metabolites: absent. Primary photobiont: present, chlorophytaceous – trebouxiaceous, chlorococcoid. Secondary photobionts (eg in cephalodia): absent.