Global occurrence: Eurasia – Asia Extratropical | Eurasia – Europe | Americas – North America (incl Mexico) | Americas – South and Central America | Eurasia – Asia Tropical | Arctic.  Substrate: rock – siliceous, siliciferous, acidic.  Life habit: lichenized (mutualistic with algal photobionts).  Thallus: crustose (crustaceous) – endosubstratal, inconspicuous, immersed | crustose (crustaceous) – episubstratal – unspecified; cracked, fissured, fractured, rimose; [th] upper surface: grey(ish) | white(ish); [th marginal and upper surface] specific structures: absent; [th] medulla amyloidity: present.  Ascomata: absent | present; ascoma: apothecial, apothecioid – hymenial; ascoma [mm]: (low) 0.5 (high) 1.2 (max) 1.5; ascoma: sessile, superficial; [ascm, if apoth] disc, mazaedium: plane, flat, flattened, expanded | subconvex, slightly convex | convex; [ascm, if apoth] disc, mazaedium: black(ish); [ascm, if apoth] margin surface; [if perith] periostiolar area, ostiole, involucrellum: black(ish); [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: brown(ish) (if pale: fawn, tan; if mid: cinnamon).  Asci: lecanoralean;[asc] tholus: thickened; [asc] tholus amyloidity (iodine reaction): present; [asc] tholus amyloidity pattern: amyloid with acuate axial body towards the apex (= Bacidia-, Buellia-, Ramalina-types etc).  Ascospores: (median) 8.0; [asp] shape: oblong, oblong-obtuse; [asp] length [µm]: (low) 12.0 (high) 16.0; [asp] width [µm]: (low) 7.0 (high) 8.5; [asp] septa: present, transversely septate; [asp] transversal septa: (median) 1.0; [asp] pigmentation: medium brown, brownish; [asp] perispore, epispore: ornamented, rough, warted, striate, cracked.  Conidiomata: absent | present.  Conidia: bacilliform, bacillary; [co] length [µm]: (low) 4.0 (high) 5.0.  Secondary metabolites: present, atranorin.  Primary photobiont: present, chlorophytaceous – trebouxiaceous, chlorococcoid.  Secondary photobionts (eg in cephalodia): absent.