Thallus thick, coarsely warted to deeply cracked-areolate. Areoles large, 2-2.5 mm diam., sharply angular, separated by deep cracks, rounded-wavy at the thallus edge, dark blue-grey or becoming brown (with age ?), with a white sheen resembling pruina. Anamorph: conidiomata pycnidial, conidia 3-5 × ca 1 μm in size. Teleomorph: ascomata apothecia, 0.3-1.0 mm diam., very numerous, 3-6 per areole, crowded and sometimes completely obscuring the areoles, elevated, round, becoming irregular through compression, black when wet. Thalline margin thin, persistent, with a white sheen, cracking radially when old. Proper margin pseudoparenchymatous, cells ca 5-8 × 3-5 μm in size. Disc dark brown-black, matt, flat, becoming pseudogyrose when old; epithecium olive-green, N+ green, with a gelatinous layer of colourless cells outside. Interascal tissue composed of paraphyses that are sparingly branched, moniliform, widening to ca 3 μm at the apices. Asci cylindric-clavate, thin outer coat K/I+ blue, wall and apical dome K/I–, 8-spored. Ascospores (9-)12-14 × 7-9 μm, broadly ellipsoidal, hyaline, thin- and smooth-walled, without a gelatinous sheath or epispore. Chemistry: thallus K–, Pd– (unidentified compound by t.l.c.).