Global occurrence: Oceania – Australasia | Eurasia – Europe | Americas – North America (incl Mexico) | Arctic.  Substrate: rock – calcareous, calciferous, basic | rock, stones, pebbles – unspecified.  Life habit: lichenized (mutualistic with algal photobionts).  Thallus: crustose (crustaceous) – episubstratal – unspecified; continuous, diffuse, effuse | granular, granulose, granulate | cracked, fissured, fractured, rimose | compartimentized – areolate, squamulate; [th] upper surface: grey(ish) | blue(ish) grey | grey(ish) blue; [th marginal and upper surface] specific structures: absent.  Ascomata: absent | present; ascoma: apothecial, apothecioid – hymenial; ascoma [mm]: (low) 0.5 (high) 1.2; ascoma: sessile, superficial; [ascm, if apoth] disc, mazaedium: plane, flat, flattened, expanded | subconvex, slightly convex | convex | distinctly convex | strongly convex, hemispherical, (sub-)globose; [ascm, if apoth] disc, mazaedium: black(ish) | blue(ish) black | black(ish) blue; [ascm, if apoth] margin excipular photobionts: absent; [ascm, if apoth] subhymenial layers, hypothecium; [if perith] basal excipulum: green(ish) black | green(ish) blue | blue(ish) green (turquoise); [ascm] paraphyses/-oids: present.  Asci: lecanoralean; [asc] tholus: thickened; [asc] tholus amyloidity (iodine reaction): present; [asc] tholus amyloidity pattern: with amyloid tube, ring (= Collema-, Micarea-, Porpidia-, Psora-types etc).  Ascospores: (median) 8.0; [asp] shape: ellipsoidal; [asp] length [µm]: (low) 7.0 (high) 10.0; [asp] width [µm]: (min) 2.5 (low) 3.0 (high) 4.5; [asp] septa: absent – spore lumen unilocular, monolocular | present; [asp] septa: transversely septate; [asp] transversal septa: (low) 0.0 (high) 1.0; [asp] pigmentation: hyaline, colourless; [asp] perispore, epispore: not apparent.  Secondary metabolites: present.  Primary photobiont: present, chlorophytaceous – trebouxiaceous, chlorococcoid.  Secondary photobionts (eg in cephalodia): absent.