Global occurrence: Africa (incl Madagascar) | Oceania – Australasia | Eurasia – Europe | Americas – North America (incl Mexico) | Arctic. Substrate: rock – calcareous, calciferous, basic. Life habit: lichenized (mutualistic with algal photobionts). Thallus: crustose (crustaceous) – episubstratal – unspecified [th] upper surface: brown(ish) (if pale: fawn, tan; if mid: cinnamon) | grey(ish) brown | red(dish) brown (if pale: orange brown) | white(ish) brown (beige) | brown(ish) red (carneous); [th upper surface]: epruinose | pruinose; [th upper surface] pruina: scarce, sparse, fine; [th marginal and upper surface] specific structures: absent; [th] morphol substructures (eg areoles, lobes, branches) width [mm]: (low) 0.5 (high) 5.0;[th] morphol substructures (eg areoles, lobes, branches) upper surface: subsquamulose | squamulose. Ascomata: absent | present; ascoma: apothecial, apothecioid – hymenial; ascoma [mm]: (median) 1.5 (max) 2.5; [ascm, if apoth] disc, mazaedium: epruinose; [ascm] paraphyses/-oids: present. Asci: lecanoralean; [asc] tholus: thickened; [asc] tholus amyloidity (iodine reaction): absent; [asp] length [µm]: (low) 4.0 (high) 8.0; [asp] width [µm]: (low) 1.5 (high) 3.0; [asp] septa: absent – spore lumen unilocular, monolocular; [asp] pigmentation: hyaline, colourless; [asp] perispore, epispore: not apparent. Secondary metabolites: absent. Primary photobiont: present. Secondary photobionts (eg in cephalodia): absent. Primary photobiont: chlorophytaceous – trebouxiaceous, chlorococcoid.