Thallus crustose, effuse, ecorticate, rarely with effigurate margins, without a lower cortex, without soredia or isidia. Medulla I-. Corticolous, saxicolous or foliicolous. Photobiont green, and , mostly in small groups dispersed throughout thallus. Apothecia lecideine, solitary or clustered, sessile or subinnate, small, 0.3-1.5 mm diam., matt or glossy, rarely pruinose, plane to moderately or strongly convex, young fruits concave with flat disc and swollen margins, margins persistent or disappearing with age. Epithecium of much thickened and branching paraphyses tips, colourless to black. Hymenium colourless 40-60 µm tall, rarely lower (30 µm) or taller (75 µm). Paraphyses simple, much branched in upper part, apical cells swollen, to 8 µm diam., always pigmented, pigment in apical cap. Asci subcylindrical or -type with thickened walls, often with an I+ blue tholus. Ascospores 1-septate, oblong-ellipsoid, oval or fabiform with rounded or pointed ends, colourless, 8 per ascus.