Global occurrence: Eurasia – Europe | Americas – North America (incl Mexico) | Arctic. Substrate: lichens, lichenized fungi. Life habit: lichenized (mutualistic with algal photobionts). Thallus: crustose (crustaceous) – endosubstratal, inconspicuous, immersed; [th marginal and upper surface] specific structures: absent. Ascomata: absent | present; ascoma: apothecial, apothecioid – hymenial; ascoma: sessile, superficial; [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) | hyaline, colourless; [ascm] paraphyses/-oids: present. 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: ellipsoidal; [asp] width [µm]: (low) 4.0 (high) 6.0; [asp] septa: absent – spore lumen unilocular, monolocular; [asp] pigmentation: hyaline, colourless; [asp] perispore, epispore: not apparent. Secondary metabolites: absent. Primary photobiont: present; chlorophytaceous – trebouxiaceous, chlorococcoid. Secondary photobionts (eg in cephalodia): absent.