Thallus: squamulose, scattered or sometimes forming rosette-shaped patches squamules: shallowly or deeply lobed, flat to convex, up to 2 mm diam. upper surface: olive-brown to brown, not sorediate upper cortex: not developed but with a yellowish epinecral layer (11-13 µm thick) medulla: partly consisting of loosely interwoven hyphae and partly paraplectenchymatous (cells: elongated, 1-1.5 µm thick); algal layer: 45-100 µm thick lower cortex: proso- to paraplectenchymatous, 15-26 µm thick; cells: globose, up to 6.5 µm in diam. lower surface: paler than the upper surface, attached by a tuft of rhizines or a branched umbilicus Apothecia: one per squamule (extremely rarely 2-3), adnate, with a raised rim when mature; disc: red to yellow-brown, 0.5-1 mm in diam.; epihymenium: yellow-brown, K-; hymenium: I+ blue, 120-150 µm high asci: clavate to obclavate; wall: I+ orange but blue after pretreatment with K, >100-spored ascospores: subglobose to ellipsoid, 5-8 x 2-4 µm Pycnidia: no data available conidia: ovoid-fusiform, 3.1-4.3 x 1.8-2.4 (-3.1) µm Spot tests: all negative Secondary metabolites: none detected. Substrate and ecology: commonly on soil and acidic rocks, occasionally on calcareous rocks in deserts and other open, arid habitats World distribution: SW North America, southern and West Africa, Europe, Asia, Australia Sonoran distribution: desert areas of Arizona, southern California, Sonora, Sinaloa, Baja California and Baja California Sur.