Global occurrence: Eurasia – Europe | Arctic.  Substrate: rock – siliceous, siliciferous, acidic.  Life habit: lichenized (mutualistic with algal photobionts).  Thallus: placodioid-crustose, placodioid-foliose; [th] upper surface: yellow(ish) (if dull: buff) | yellow(ish) green | grey(ish) white; [th] morphol substructures (eg areoles, lobes, branches) width [mm]: (low) 1.0 (high) 2.0.  Ascomata: absent | present; ascoma: apothecial, apothecioid – hymenial; ascoma: sessile, superficial | subpedicellate, substipitate, subpedunculate, substalked; [ascm, if apoth] disc, mazaedium: brown(ish) (if pale: fawn, tan; if mid: cinnamon) | red(dish) brown (if pale: orange brown); [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: [asp] septa: absent – spore lumen unilocular, monolocular; [asp] pigmentation: hyaline, colourless; [asp] perispore, epispore: not apparent.  Secondary metabolites: present, usnic acid | zeorin (hopane-6α,22-diol).  Primary photobiont: present, chlorophytaceous – trebouxiaceous, chlorococcoid.  Secondary photobionts (eg in cephalodia): absent.