Thallus of scattered, white, sorediate spots, 0.5-1.5 mm diam., in patches 1-2 cm diam., soredia white, coarse, granular, wrinkled-rimose or ± continuous, corticolous, lignicolous. Apothecia black, convex, 0.2-0.6 mm diam., margin thin, concolorous with disc, soon disappearing. Epithecium blue-black. Hymenium 110 µm tall. Paraphyses branched-anastomosing, 1.5 µm thick, apices slightly swollen to 2 µm thick. Hypothecium colourless or pale straw-coloured, massive, 350-400 µm thick. Asci 2-spored. Ascospores colourless, ellipsoid, 40-50 × 24-28(-32) µm, wall c. 3 µm thick. Chemistry: Thallus K-, C-, KC+ pink, Pd ± rust red.