Global occurrence: Eurasia – Europe | Americas – North America (incl Mexico) | Arctic.  Substrate: bark, cork, plant surface – trunks, branches, twigs.  Life habit: lichenized (mutualistic with algal photobionts).  Thallus: crustose (crustaceous) – episubstratal – unspecified | squamulose (squamulous); compartimentized – areolate, squamulate; [th] upper surface: yellow(ish) grey | yellow(ish) brown | grey(ish) white; [th marginal and upper surface] specific structures: present; [th margin] cilia, cilioid structures: absent; [th upper surface] isidia, isidioid structures: absent; [th upper surface] soredia, soralia, soralioid structures: present; [th] morphol substructures (eg areoles, lobes, branches) width [mm]: (median) 0.4 (max) 1.0.  Ascomata: absent.  Primary photobiont: present, chlorophytaceous – trebouxiaceous, chlorococcoid.  Secondary photobionts (eg in cephalodia): absent.