Global occurrence: Eurasia – Europe | Americas – North America (incl Mexico) | Arctic. Substrate: rock – siliceous, siliciferous, acidic | rock, stones, pebbles – unspecified. Life habit: lichenized (mutualistic with algal photobionts). Thallus: crustose (crustaceous) – episubstratal – unspecified; compartimentized – areolate, squamulate; [th] upper surface: white(ish) green | blue(ish) white | yellow(ish) white (ivory, off-white, cream-coloured); [th marginal and upper surface] specific structures: absent; [th] morphol substructures (eg areoles, lobes, branches) upper surface: smooth, plane. Ascomata: absent | present; ascoma: apothecial, apothecioid – hymenial; ascoma [mm]: (low) 0.3 (high) 0.6 (max) 1.0; ascoma: 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: white(ish) green | yellow(ish) white (ivory, off-white, cream-coloured); [ascm, if apoth] subhymenial layers, hypothecium; [if perith] basal excipulum: hyaline, colourless; [ascm] paraphyses/-oids: present; [ascm] paraphyses/-oid cells width [µm]: (low) 1.5 (high) 2.5; [ascm] paraphyses/-oid apical cells width [µm]: (median) 3.5; [ascm] epihymenium, epithecium: blue(ish) | yellow(ish) brown. Asci: lecanoralean; [asc] tholus: thickened; [asc] tholus amyloidity (iodine reaction): present; [asc] tholus amyloidity pattern: amyloid with widening axial body towards the apex (= Lecanora-, Parmelia-, Rinodina-types etc). Ascospores: (median) 8.0; [asp] shape: subglobose, subspherical | ellipsoidal; [asp] length [µm]: (low) 8.0 (high) 14.0; [asp] width [µm]: (low) 5.0 (high) 6.0; [asp] septa: absent – spore lumen unilocular, monolocular; [asp] pigmentation: hyaline, colourless; [asp] perispore, epispore: not apparent. Conidiomata: absent | present. Conidia: [cur] – curved, unciform, falcate, sickle-shaped; [co] length [µm]: (low) 15.0 (high) 20.0. Secondary metabolites: present, usnic acid | unknown/unidentified pigment(s). Primary photobiont: present, chlorophytaceous – trebouxiaceous, chlorococcoid. Secondary photobionts (eg in cephalodia): absent.