Thallus crustose, thin or evanescent, smooth or finely rimose-cracked, pale to dark grey, occasionally tinged pale yellow, green or dull brown. Prothallus not evident. Soralia and isidia absent. Photobiont Trentepohlia. Anamorph: conidiomata pycnidia, often thinly white- or greenish-pruinose. Conidia 3-5 × 0.5-1 (-2) μm, bacilliform or slightly dumb-bell shaped. Teleomorph: ascomata lirellate apothecia, 0.7-2.5 (-4) × (0.1-) 0.2-0.5 mm, 80-120 µm high, mostly elongate, infrequently branched, rarely stellate, scattered or contiguous, sessile. Disc very variable, a slit frequently becoming ± exposed with age or fully exposed from the beginning. Thalline exciple absent. True exciple and/or disc sometimes ± grey or green-pruinose, the exciple K– in section. Epithecium brown, K–. Hymenium 60-80 μm tall, I+ red. Ascus broadly clavate, fissitunicate, 8-spored. Ascospores (18-) 20-37 × (5-) 6-9 μm, 4- to 6-septate, clavate to clavate-ellipsoidal, the middle cells somewhat enlarged, with a thin epispore and rounded ends, becoming red-brown with age. Chemistry: thallus C–, K–, KC–, Pd–, UV– (no lichen products detected).