Thallus dingy grey-white to greenish-grey or creamish, continuous, minutely wrinkled, verrucose-papillate, papillae minute, subglobose, 0.1 mm diam., to minutely areolate-cracked, areolae separated by narrow cracks, 2-6 cm diam., sometimes delimited at margins by a narrow, black prothallus. Apothecia sessile or subpedicellate, round to irregular, scattered or crowded, 1.0-2.5 mm diam., disc plane to subconvex-irregular, dark red-brown or black, with a thin to dense grey-white pruina, margins persistent, conspicuous, concolorous with thallus or paler, entire to crenulate-verrucose. Epithecium red-brown, 15-17 µm thick. Hymenium pale yellow-brown, 50-130(-180) µm tall. Hypothecium pale brownish or colourless, 30-60 µm thick. Paraphyses filiform, dense, not capitate at apices. Asci clavate, 8-spored, with a prominent apical dimple. Ascospores spiral in ascus, biseriate, fabiform, curved, apices rounded, contents oily-granular, 20-30(-34) × 7-10.2(-13) µm. Chemistry: Cortex K+ yellow, Pd-. Thamnolic acid.