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) – endosubstratal, inconspicuous, immersed; [th marginal and upper surface] specific structures: absent; [th] medulla amyloidity: absent. Ascomata: absent | present; ascoma: apothecial, apothecioid – hymenial; ascoma [mm]: (median) 0.8 (max) 1.0; ascoma: sessile, superficial; [ascm, if apoth] disc, mazaedium: subconvex, slightly convex | convex | distinctly convex | strongly convex, hemispherical, (sub-)globose; [ascm, if apoth] disc, mazaedium: black(ish) | red(dish) brown (if pale: orange brown) | brown(ish) red (carneous); [ascm, if apoth] margin surface; [if perith] periostiolar area, ostiole, involucrellum: green(ish) black | green(ish) blue | black(ish) green | blue(ish) green (turquoise); [ascm, if apoth] margin excipular photobionts: absent; [ascm, if apoth] subhymenial layers, hypothecium; [if perith] basal excipulum: red(dish) | red(dish) brown (if pale: orange brown) | brown(ish) red (carneous); [ascm] paraphyses/-oids: present. Asci: lecanoralean; [asc] tholus: thickened; [asc] tholus amyloidity (iodine reaction): present. Ascospores: (median) 8.0; [asp] shape: ellipsoidal | elongate-fusiform, ellipsoidal-fusiform; [asp] length [µm]: (low) 8.0 (high) 12.0; [asp] width [µm]: (low) 2.7 (high) 3.8; [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.