Thallus greenish-grey to yellowish-grey, smooth or wrinkled, verrucose or plicate often ± subareolate or ± granular, limited, often intersected by black lines of marginal prothallus, often forming extensive mosaics, 1-5 cm diam., or sometimes thallus reduced to scattered areolae (especially on dead wood), corticolous or lignicolous. Apothecia few to many, sessile, round to irregular, disc black, matt or shining, plane to subconvex, 0.3-1.0 mm diam., margins thick, black, entire to irregularly crenulate, persistent. Hypothecium red-brown. Asci 51 × 15-18 µm with a distinct, I+ blue apical tholus 7-8 µm thick. Ascospores (10-)12-15.3 × 5-6.8 µm. Chemistry: Cortex K+ yellow, C+ orange-red. Xanthones.