Thallus heteromerous, foliose, dorsiventral, monophyllous, attached to substrate by a ± central umbilicus. Lobes entire, strongly dissected, pliable and somewhat leathery when wet, brittle when dry. Upper surface pustulate, pustules ± convex, round or oval, marginal or ± central, ± pruinose, cracked or lacerate, brown, dark brown, grey-brown or greyish, rarely reddish, with or without isidia, soredia or verrucae. Photobiont green, . Lower surface lacunose, lacunae corresponding to pustules of upper surface, smooth or verrucose, without rhizines. Apothecia lecideine, sessile to pedicellate, disc plane, smooth or irregular, margins persistent. Ascospores 1 (rarely 2) per ascus, large, muriform, pale to dark brown.