Thallus foliose, dorsiventral, heteromerous, lobate, orbicular, 3-15 cm diam., uniformly closely attached to substrate even at margins, corticolous or saxicolous. Lobes variable, sublinear, apically obtuse to subirregular, apically rounded, margins smooth, black-rimmed, without cilia or other ornamentation. Upper cortex of palisade plectenchyma with a thin, pored epicortex. Upper surface smooth or wrinkled, isidia, pustules and soralia present or absent, pseudocyphellae and maculae absent. Medulla white. Photobiont green. Lower surface black or pale brown, broad-lobed species often with a narrow, brown, naked marginal zone. Rhizines moderately abundant, uniformly simple, often pale at apices. Apothecia uniform, sessile to subpedicellate, 1-3 mm diam., disc imperforate, red-brown, shining or matt, thalline exciple concolorous with thallus, smooth, isidiate, sorediate or pustulate. Ascospores 8 per ascus, simple, colourless, mostly within range 7-13 × 6-10 µm.