Thallus 0.15-0.2 mm thick, roughened in parts, white, grey or brownish-grey, matt, areolate-cracked, areolae angular, 0.2-0.6 mm diam., plane to subconvex, in patches 1-5 cm diam., saxicolous. Apothecia crowded, often densely developed, ± innate to sessile, solitary to 1-4-confluent, rounded or angular, 0.2-0.5 mm diam., disc flat, black, matt, epruinose, margin thin, black, entire, ± flexuose in older fruits. Hypothecium thick, brown-black. Ascospores biseriate, brown, broadly ellipsoid, or subovoid to ± fabiform, apices rounded or slightly pointed, slightly constricted at septum, 12.8-16 × 6-6.4 µm, septum to 1.5 µm thick.