Thallus grey-white or pale greenish-grey, minutely roughened-verrucose, slightly cracked to ± areolate-cracked, corticolous, delimited by a thin, black, wavy prothallus. Apothecia sessile, 0.1-1.5 mm diam., concave to plane, sparse or crowded-confluent, rounded to irregular through mutual pressure, margins prominent, concolorous with disc, flexuose, disc black, matt, epruinose. Epithecium blue-black, 8-10(-30) µm thick, dense. Hymenium 30-50 µm tall, colourless. Hypothecium 55 µm thick, colourless. Paraphyses slender, 1.5-2 µm thick, apices blackened, slightly thickened to 3 µm. Asci 34-45 × 10-14 µm, clavate, upper part pale to medium blue in I, with an I+ blue apical tholus to 5 µm thick. Ascospores uni- or biseriate, broadly oval with rounded or slightly pointed ends, 13-17(-19) × (6.5-)8-9 µm, straight, not constricted at septum.