Thallus very variable, thin, scurfy-uneven, ± cracked, to rather thick, nodular-uneven, grey-green or dark green-brown to black. Prothallus not differentiated. Isidia and soralia absent. Photobiont chlorococcoid, with cells 7-17 (-20) µm diam. Anamorph: not observed. Teleomorph: ascomata apothecia, frequent, 0.3-0.8 mm diam., flat to shallowly convex, slightly constricted at the base, dark brown-black or less often dark red-brown, glossy when young, sometimes a dull pale brown in extreme shade. The exciple sometimes persists but is often excluded. Epithecium blue-green, green-brown or olive-brown, colours often intermixed. Hymenium and hypothecium hyaline. Interascal tissue of paraphyses, septate, branched
and anastomosed in a gelatinous matrix, resembling excipular hyphae, the apices not or only slightly thickened. Asci broadly clavate to clavate-cylindrical, Lecanora-type with a broad apical cushion, 8-spored. Ascospores (15-) 20-30 (-40) × 2-3 µm, 3- to 7-septate, needle-shaped, helically twisted, remaining curved after ejection; hyaline, smooth- and thin-walled, without an epispore, gelatinous sheath or appendages. Chemistry: All parts C-, K–, KC–, Pd– (no lichen products detected by TLC).