Thallus foliose, dorsiventral, heteromerous, closely attached to sub-strate, suborbicular to spreading, corticolous or saxicolous. Lobes narrow, radiating, pinnate, subpinnately-dichotomous to subdichotomous, discrete or confluent at margins, centrally confluent, eventually verrucose to subcrustose. Upper surface glaucous-grey, glaucous-white, pale grey to dark grey, smooth or wrinkled, with or without soredia, with or without pruina. Medulla white or pale yellow in upper part, occasionally reddish. Photobiont green, . Lower surface corticate, of longitudinal, thick, brown hyphae, black, rarely pale grey to grey, without rhizines. Apothecia sessile to subpedicellate, lecanorine, disc black, epruinose occasionally lightly grey-or purple-pruinose, margins distinct, well-developed, with persistent algal cells at the upper edge or along the greater part of the thalline exciple. Ascospores 8 per ascus, brown to dark brown, thick-walled, 1-septate, ellipsoid to elongate-ellipsoid, not constricted at centre.