Thallus greenish-grey to grey-white, matt, thin, covered with small, suberect (ascending) somewhat flattened lobules, thallus spreading, to 10 cm diam., corticolous. Apothecia usually present, to 2 mm diam., sessile, constricted at base, plane to somewhat convex, distinctly marginate, disc and margins concolorous, rust-brown or blackish with rust-brown granular pruina. Excipulum biatorine. Hypothecium colourless to brownish. Hymenium colourless 150-200 µm tall, covered with brown anthraquinone crystals. Asci and paraphyses as in genus description. Ascospores 1 per ascus, colourless, muriform, ellipsoid, 80-120 × 25-45 µm.