Thallus: umbilicate, mono- or polyphyllous (sometimes lobate), +circular to irregular in shape, thin, brittle, 1-4(9) cm in diam.; upper surface: brown, smooth where not patchily covered with granular to coralloid, or club- to leaf-like isidia; lower surface: light to dark brown or black, smooth to occasionally broadly pitted; Apothecia: rare, black, sessile to stipitate, gyrose, up to 1.5 mm in diam.; asci: clavate, 8-spored; ascospores: hyaline, simple, broadly ellipsoid, 6-12 x 4-8 µm; Spot tests: medulla K-, C+ red, KC+ red, P-; Secondary metabolites: gyrophoric, lecanoric and hiascic acids.; Substrate and ecology: on siliceous rocks, boreal to low alpine vegetation zones, usually under the snow in winter; World distribution: Europe, Asia, North and South America; Sonoran distribution: in montane habitats in moister microhabitats of Arizona.; Notes: Among the Sonoran Umbilicariae, Umbilicaria deusta is the only one that reproduces by isidia, found on the upper surface.