Global occurrence: Africa (incl Madagascar) | Eurasia – Asia Extratropical | Eurasia – Europe | Americas – North America (incl Mexico) | Eurasia – Asia Tropical | Arctic. Substrate: rock – siliceous, siliciferous, acidic | rock, stones, pebbles – unspecified.  Life habit: lichenized (mutualistic with algal photobionts).  Thallus: peltate, umbilicate; thallus: continuous, diffuse, effuse; [th] upper surface: grey(ish) | brown(ish) grey | red(dish) grey | white(ish) grey | grey(ish) white; [th upper surface]: epruinose | pruinose; [th upper surface] pruina: scarce, sparse, fine; [th marginal and upper surface] specific structures: absent; [th] morphol substructures (eg areoles, lobes, branches) width [mm]: (low) 30.0 (high) 50.0 (max) 80.0; [th] morphol substructures (eg areoles, squamules): distantly discontiguous; [th] morphol substructures (eg areoles, lobes, branches) upper surface: smooth, plane | verrucose, warted | cracked, fissured, fractured, rimulose, subrimose; [th] lower surface: brown(ish) (if pale: fawn, tan; if mid: cinnamon) | red(dish) brown (if pale: orange brown) | grey(ish) white | red(dish) white (pink); [th lower surface] specific structures: present; [th lower surface] rhizines, rhizoid structures: presentl; [th lower surface] rhizines, rhizinoid structures: unbranched, simple | irregularly branched, irregular.  Ascomata: absent | present; ascoma: apothecial, apothecioid – hymenial; ascoma [mm]: (low) 1.0 (high) 4.0; ascoma: immersed, innate | subsessile, subimmersed, adnate, semi-immersed, emergent | sessile, superficial; [ascm, if apoth] disc, mazaedium: plane, flat, flattened, expanded | subconvex, slightly convex; [ascm, if apoth] disc, mazaedium: black(ish); [ascm, if apoth] disc, mazaedium: epruinose; [ascm, if apoth] margin surface; [if perith] periostiolar area, ostiole, involucrellum: black(ish); [ascm, if apoth] margin excipular photobionts: absent; [ascm, if apoth] subhymenial layers, hypothecium; [if perith] basal excipulum: brown(ish) (if pale: fawn, tan; if mid: cinnamon); [ascm] paraphyses/-oids: present; [ascm] epihymenium, epithecium: black(ish).  Asci: lecanoralean; [asc] tholus: thickened; [asc] tholus amyloidity (iodine reaction): present; [asc] tholus amyloidity pattern: entirely amyloid (= Catillaria-, Teloschistes-types etc).  Ascospores: (median) 8.0; [asp] shape: subglobose, subspherical | broadly ellipsoidal | ellipsoidal; [asp] length [µm]: (low) 18.0 (high) 24.0; [asp] width [µm]: (low) 11.0 (high) 21.0; [asp] septa: absent – spore lumen unilocular, monolocular | present; [asp] septa: muriformly septate – muriform, submuriform; [asp] pigmentation: hyaline, colourless | pale brown | medium brown, brownish; [asp] perispore, epispore: not apparent.  Conidiomata: absent | present.  Conidia: cylindrical; [co] length [µm]: (low) 3.0 (high) 4.0.  Secondary metabolites: present, gyrophoric acid.  Primary photobiont: present, chlorophytaceous – trebouxiaceous, chlorococcoid.  Secondary photobionts (eg in cephalodia): absent.