Global occurrence: Americas – North America (incl Mexico) | Arctic.  Substrate: rock – siliceous, siliciferous, acidic | rock, stones, pebbles – unspecified.  Life habit: lichenized (mutualistic with algal photobionts).  Thallus: subfruticose (subfruticous), fruticulose, dactyliform; [th] upper surface: grey(ish) green | green(ish) yellow; [th upper surface]: epruinose; [th marginal and upper surface] specific structures: absent; [th] morphol substructures (eg areoles, lobes, branches) width [mm]: (low) 0.5 (high) 1.0; [th] morphol substructures (eg areoles, squamules): discontiguous, dispersed (throughout the thallus); [th] morphol substructures (eg areoles, lobes, branches) upper surface: bullate.  Ascomata: absent | present; ascoma: apothecial, apothecioid – hymenial; ascoma [mm]: (low) 0.5 (high) 4.0; ascoma: sessile, superficial; [ascm, if apoth] disc, mazaedium: concave | plane, flat, flattened, expanded; [ascm, if apoth] disc, mazaedium: yellow(ish) (if dull: buff) | white(ish) | yellow(ish) brown; [ascm, if apoth] disc, mazaedium: pruinose; [ascm, if apoth] disc, mazaedium pruina: dense; [ascm, if apoth] margin surface; [if perith] periostiolar area, ostiole, involucrellum: grey(ish) green | green(ish) yellow; [ascm, if apoth] margin excipular photobionts: present | abundant; [ascm, if apoth] subhymenial layers, hypothecium; [if perith] basal excipulum: hyaline, colourless | red(dish) yellow (orange, orange yellow); [ascm] paraphyses/-oids: present; [ascm] paraphyses/-oid cells width [µm]: (low) 1.0 (high) 1.5; [ascm] paraphyses/-oid apical cells width [µm]: (low) 2.0 (high) 2.5; [ascm] epihymenium, epithecium: yellow(ish) (if dull: buff).  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: broadly ellipsoidal | ellipsoidal; [asp] length [µm]: (min) 8.0 (low) 10.0 (high) 14.0 (max) 16.0; [asp] width [µm]: (low) 5.0 (high) 6.0 (max) 8.0; [asp] septa: absent – spore lumen unilocular, monolocular; [asp] pigmentation: hyaline, colourless; [asp] perispore, epispore: not apparent.  Conidiomata: absent | present.  Conidia: filiform, vermiform | [cur] – curved, unciform, falcate, sickle-shaped; [co] length [µm]: (min) 12.0 (low) 15.0 (high) 25.0.  Secondary metabolites: present, isousnic acid | usnic acid | unknown/unidentified compound(s).  Primary photobiont: present, chlorophytaceous – trebouxiaceous, chlorococcoid.  Secondary photobionts (eg in cephalodia): absent.