Global occurrence: Oceania – Australasia | Eurasia – Europe | Americas – North America (incl Mexico) | Arctic. Substrate: rock – siliceous, siliciferous, acidic. Life habit: lichenized (mutualistic with algal photobionts). Thallus: crustose (crustaceous) – episubstratal – unspecified; cracked, fissured, fractured, rimose | compartimentized – areolate, squamulate; [th] upper surface: yellow(ish) (if dull: buff); [th marginal and upper surface] specific structures: absent; [th] medulla amyloidity: absent. Ascomata: absent | present; ascoma: apothecial, apothecioid – hymenial; ascoma [mm]: (low) 0.2 (high) 0.5; ascoma: immersed, innate; [ascm, if apoth] disc, mazaedium: plane, flat, flattened, expanded; [ascm, if apoth] disc, mazaedium: black(ish); [ascm, if apoth] subhymenial layers, hypothecium; [if perith] basal excipulum: brown(ish) (if pale: fawn, tan; if mid: cinnamon); [ascm] paraphyses/-oids: present; [ascm] epihymenium, epithecium: brown(ish) (if pale: fawn, tan; if mid: cinnamon) | green(ish) brown (olive brown). Asci: lecanoralean; [asc] tholus: thickened; [asc] tholus amyloidity (iodine reaction): present; [asc] tholus amyloidity pattern: amyloid with acuate axial body towards the apex (= Bacidia-, Buellia-, Ramalina-types etc). Ascospores: (median) 8.0; [asp] shape: oblong, oblong-obtuse; [asp] length [µm]: (low) 13.0 (high) 15.0; [asp] width [µm]: (low) 6.5 (high) 8.5; [asp] septa: present, transversely septate; [asp] transversal septa: (median) 1.0; [asp] pigmentation: medium brown, brownish; [asp] perispore, epispore: ornamented, rough, warted, striate, cracked. Conidiomata: absent | present. Conidia: bacilliform, bacillary; [co] length [µm]: (low) 4.5 (high) 5.5. Secondary metabolites: present, arthothelin | stictic acid. Primary photobiont: present, chlorophytaceous – trebouxiaceous, chlorococcoid. Secondary photobionts (eg in cephalodia): absent.