Thallus rather fragile, irregularly spreading or ± orbicular, 2-8 cm diam. Lobes narrow, 1-2 mm wide, subrotund, imbricate, axils sinuous, apices rounded and slightly crenulate, margins entire, cilia distinct, evenly dispersed, 0.5 mm long. Upper surface smooth, continuous, slightly maculate apically, greenish-grey to pale brownish, pustules laminal and marginal, eroding apically to expose white or pale yellow medulla. Medulla faintly yellow. Lower surface black with a smooth, brown, naked marginal zone. Rhizines simple or furcate, black, rather sparse. Apothecia occasional, sessile, disc brown, to 5 mm diam., margins crenulate, becoming pustulate, often deeply lacerate, thalline exciple strongly wrinkled, pustulate, greenish. Ascospores 12-24 × 7-8 µm. Chemistry: Cortex K+ yellow; medulla K-, C+ orange-pink, KC+ orange-pink, Pd-. Gyrophoric acid and atranorin.