Thallus foliose, dorsiventral, heteromerous, lobate, ± radiate, corticolous, saxicolous or terricolous, rosette-forming to irregularly spreading, loosely to closely attached. Lobes ± inflated, hollow, upper surface corticate, perforate (two species lack perforations), with or without soredia, isidia or maculae, lower surface corticate, naked, ± uniformly attached to substrate, uneven, blackened, without rhizines, walls of internal cavity white, or pigmented or blackened. Apothecia laminal, rounded, lecanorine, often cupuliform, sessile or ± subpedicellate to distinctly pedicellate, disc concave to plane, matt, shining or pruinose, eperforate, thalline exciple well-developed. Epithecium pigmented, occasionally with granular inclusions. Hymenium colourless. Hypothecium chondroid, of thick-walled, conglutinated cells. Paraphyses anastomosing, apical cells capitate or not, ± pigmented. Asci 2- or 8-spored. Ascospores colourless, simple, ellipsoid, 20-120 × 10-50 µm, thick-walled. Pycnidia immersed, minute, punctiform, laminal, with a dark apex. Conidia short, bacilliform. Taxa in the genus show a diverse chemistry, including depsides, depsidones, fatty acids and pigments.