Thallus crustose, continuous, rimose to areolate-cracked, thin or thick, granular or verrucose, occasionally subsquamulose especially at margins, white, greyish or yellowish, very rarely sorediate, corticolous and saxicolous. Photobiont green, . Apothecia lecideine, immersed to sessile, minute to large, rounded, disc black, strongly convex, occasionally roughened-scabrid or pruinose, margins thin, concolorous with disc, occasionally surrounded at base by a superficial thalline margin, often occluded. Hypothecium colourless or yellow-brown to red-brown or black and carbonaceous. Exciple continuous with or distinct from hypothecium, brown to black occasionally pale. Paraphyses thin, septate, simple or branched, brownish and slightly swollen at apices. Asci clavate, 8-spored. Ascospores greenish-brown to grey, 1-septate, without a hyaline epispore.