Thallus orbicular, to 3 cm diam., sometimes confluent with other thalli, ± closely attached. Lobes radiating, to 1 mm wide, overlapping or indistinctly separated. Upper surface pale grey to dark brown, sometimes yellowish (skyrin), sorediate. Soralia laminal or marginal, ± capitate, sometimes spreading and covering large areas of thallus, white or yellowish (skyrin). Lower surface black, rhizinate. Rhizines simple, occasionally projecting beyond lobe margins. Apothecia ± central, rarely towards lobe apices, to 1.5 mm diam., with or without rhizines on lower side. Ascospores 18-26 × 7-11 µm. Chemistry: TLC nil.