Global occurrence: Oceania – Australasia | Eurasia – Europe | Americas – North America (incl Mexico) | Arctic.  Substrate: rock – siliceous, siliciferous, acidic | rock – calcareous, calciferous, basic | rock, stones, pebbles – unspecified.  Life habit: lichenized (mutualistic with algal photobionts).  Thallus: crustose (crustaceous) – episubstratal – unspecified; [th] upper surface: grey(ish) | white(ish); [th marginal and upper surface] specific structures: absent.  Ascomata: absent | present; ascoma: apothecial, apothecioid – hymenial; ascoma [mm]: (median) 0.9; ascoma: immersed, innate | subsessile, subimmersed, adnate, semi-immersed, emergent; [ascm, if apoth] disc, mazaedium: plane, flat, flattened, expanded; [ascm, if apoth] disc, mazaedium: black(ish); [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) | black(ish) brown; [ascm] paraphyses/-oids: present; [ascm] epihymenium, epithecium: brown(ish) (if pale: fawn, tan; if mid: cinnamon) | green(ish) black | green(ish) grey.  Asci: lecanoralean; [asc] tholus: thickened; [asc] tholus amyloidity (iodine reaction): present; [asc] tholus amyloidity pattern: with amyloid cap (= Icmadophila-, Lecidea-, Pertusaria-types etc).  Ascospores: (median) 8.0; [asp] shape: ellipsoidal; [asp] length [µm]: (low) 20.0 (high) 50.0; [asp] width [µm]: (low) 13.0 (high) 24.0; [asp] septa: present, transversely septate | muriformly septate – muriform, submuriform; [asp] transversal septa: (median) 3.0; [asp] pigmentation: hyaline, colourless | pale brown | medium brown, brownish; [asp] perispore, epispore: thick, distincly halonate.  Primary photobiont: present, chlorophytaceous – trebouxiaceous, chlorococcoid.  Secondary photobionts (eg in cephalodia): absent.