Global occurrence: Antarctic – Antarctica | Oceania – Australasia | Eurasia – Europe | Americas – South and Central America | Antarctic – Southern Subpolar Islands, Subantarctic Islands. 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: grey(ish) | yellow(ish) grey; [th upper surface]: epruinose; [th marginal and upper surface] specific structures: absent; [th] morphol substructures (eg areoles, lobes, branches) width [mm]: (median) 0.5 (max) 1.0; [th] morphol substructures (eg areoles, lobes, branches) upper surface: bullate; [th] medulla amyloidity: present. Ascomata: absent | present; ascoma: apothecial, apothecioid – hymenial; ascoma [mm]: (median) 0.6 (max) 0.9; ascoma: immersed, innate | subsessile, subimmersed, adnate, semi-immersed, emergent | sessile, superficial; [ascm, if apoth] disc, mazaedium: plane, flat, flattened, expanded; [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] subhymenial layers, hypothecium; [if perith] basal excipulum: black(ish) brown; [ascm] paraphyses/-oids: present; [ascm] epihymenium, epithecium: green(ish) brown (olive brown). Asci: lecanoralean; [asc] tholus: thickened; [asc] tholus amyloidity (iodine reaction): present; [asc] tholus amyloidity pattern: with amyloid tube and flanks (= Rimularia-, Trapelia-types etc). Ascospores: (median) 8.0; [asp] shape: ellipsoidal; [asp] length [µm]: (low) 12.5 (high) 21.0; [asp] width [µm]: (low) 6.5 (high) 10.0; [asp] septa: absent – spore lumen unilocular, monolocular; [asp] pigmentation: hyaline, colourless; [asp] perispore, epispore: not apparent. Secondary metabolites: present, norstictic acid. Primary photobiont: present, chlorophytaceous – trebouxiaceous, chlorococcoid. Secondary photobionts (eg in cephalodia): absent.