Thallus 3-6 cm diam., foliose, smooth, membrane-like, often forming extensive colonies, ± deeply and irregularly lobate. Lobes 0.5-1.5 cm wide, few, thin, ± rounded, loosely attached, often partly ascending, irregularly folded, rumpled and wavy; the margin entire or rarely coarsely lacerate, sometimes ± revolute. Upper surface dark olive-green to black, with numerous, often crowded isidia on surface and margins. Isidia concolorous, globose when young, becoming flattened and squamule-like, ± horizontal or ascending. Anamorph: no information available. Teleomorph: ascomata apothecia, very rare, laminal. Disc 1.5-2.5 mm, flat, the thalline margin smooth or ± striate. Ascospores 26-34 × 6-6.5 μm, ellipsoidal to fusiform, 3- to 5-septate.