Global occurrence: Eurasia – Europe | Americas – North America (incl Mexico) | Arctic. Substrate: rock – siliceous, siliciferous, acidic. Life habit: lichenized (mutualistic with algal photobionts). Thallus: crustose (crustaceous) – episubstratal – unspecified; cracked, fissured, fractured, rimose | compartimentized – areolate, squamulate; [th] upper surface: green(ish) grey | yellow(ish) grey | brown(ish) green (olivaceous, olive green) | brown(ish) yellow (ochraceous, ochre) | red(dish) white (pink); [th marginal and upper surface] specific structures: absent. Ascomata: absent | present; ascoma: apothecial, apothecioid – hymenial; ascoma: immersed, innate; [ascm, if apoth] disc, mazaedium: green(ish) brown (olive brown) | red(dish) brown (if pale: orange brown) | white(ish) red (rose); [ascm] paraphyses/-oids: present. Asci: lecanoralean; [asc] tholus: thickened; [asc] tholus amyloidity (iodine reaction): absent. Ascospores: (median) 8.0; [asp] length [µm]: (low) 9.0 (high) 12.0; [asp] width [µm]: (low) 5.0 (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 – trentepohliaceous, trentepohlioid. Secondary photobionts (eg in cephalodia): absent.