Global occurrence: Eurasia – Asia Extratropical | Eurasia – Europe | Americas – North America (incl Mexico) | Arctic. Substrate: wood – dead, living | bark, cork, plant surface – trunks, branches, twigs. Life habit: lichenized (mutualistic with algal photobionts). Thallus: foliose (foliaceous), leaf-like; thallus: continuous, diffuse, effuse; [th] upper surface: green(ish) | yellow(ish) (if dull: buff) | yellow(ish) grey; [th marginal and upper surface] specific structures: absent; [th] morphol substructures (eg areoles, lobes, branches) width [mm]: (low) 1.0 (high) 5.0; [th] lower surface: yellow(ish) (if dull: buff) | brown(ish) white; [th lower surface] specific structures: present; [th lower surface] rhizines, rhizoid structures: present; [th lower surface] rhizines, rhizinoid structures: squarrosely branched, squarrose. Ascomata: absent | present; ascoma: apothecial, apothecioid – hymenial; ascoma [mm]: (low) 2.0 (high) 6.0; ascoma: sessile, superficial; [ascm, if apoth] disc, mazaedium: red(dish) brown (if pale: orange brown); [ascm, if apoth] margin surface; [if perith] periostiolar area, ostiole, involucrellum: green(ish) | yellow(ish) (if dull: buff) | yellow(ish) grey; [ascm, if apoth] margin excipular photobionts: present; [ascm, if apoth] subhymenial layers, hypothecium; [if perith] basal excipulum: hyaline, colourless; [ascm] paraphyses/-oids: present; [ascm] epihymenium, epithecium: brown(ish) (if pale: fawn, tan; if mid: cinnamon) | red(dish) brown (pale: orange 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] length [µm]: (low) 4.0 (high) 10.0; [asp] width [µm]: (low) 2.5 (high) 6.0; [asp] septa: absent – spore lumen unilocular, monolocular; [asp] pigmentation: hyaline, colourless; [asp] perispore, epispore: not apparent. Conidiomata: absent | present. Conidia: fusiform; [co] length [µm]: (low) 3.5 (high) 8.0. Secondary metabolites: present, pinastric acid | usnic acid | vulpinic acid. Primary photobiont: chlorophytaceous – trebouxiaceous, chlorococcoid. Secondary photobionts (eg in cephalodia): absent.