Thallus foliose, lobate, heteromerous, attached by adhesive discs below, or rarely by the whole lower cortex. Lobes inflated, ± solid in some species, without perforations in the upper surface, with or without soredia, without isidia or pseudocyphellae. Medulla white, loose, arachnoid. Lower surface black, corticate, wrinkled, thin, often fissured or perforate, without rhizines. Photobiont green, . Apothecia lecanorine, sessile or subpedicellate, disc concave to plane, rarely perforate, red-brown to yellowish-brown, epruinose. Ascospores simple, colourless, 8 per ascus. Pycnidia common in fertile species, minute, black, punctiform, immersed in upper surface. Conidia cylindrical, straight.