Thallus heteromerous, foliose, dorsiventral, lobate, often very large, orbicular, rosette-forming or irregularly laciniate or ± dichotomously branched or polyphyllous, rarely ± monophyllous, loosely to closely attached. Lobes very variable, narrow, strap-shaped, ± dichotomously branching with distinctly bifurcating apices which may be pointed, blunt, or rounded, complex, imbricate, margins entire or variously incised orfolded often with conspicuous, elongate or verruciform pseudocyphellae, often free and ascending, tough, thick and coriaceous to thin and fragile. Upper surface smooth or wrinkled, or ± scabrid or hairy, often deeply or shallowly faveolate, with faint or marked reticulum of interconnecting ridges, shining, matt or dull, often conspicuously maculate, with or without pseudocyphellae, isidia, phyllidia or soredia. Medulla white or yellow. Photobiont green ( or -like) or blue-green (). Internal cephalodia containing present in species with a green photobiont. Lower surface glabrous in some species but usually ± tomentose, tomentum pale to dark, thick and felted to indistinctly pubescent. Pseudocyphellae always present, white or yellow, sparse to frequent, ± immersed in tomentum to raised-conical, round to irregular, margins distinct or indistinct. Apothecia hemiangiocarpic, emergent, sessile to pedicellate, laminal or marginal, rounded, margins entire or crenate-striate, phyllidiate, isidiate or sorediate in some species, disc matt or shining, sometimes white-pruinose, thalline exciple well-developed, smooth to verrucose or areolate-scabrid, hairy, sorediate or maculate. Ascospores 8 per ascus at maturity, colourless or brown, simple at first, becoming polaribilocular to 3-septate.