Thallus orbicular, closely attached, to 5 cm diam., saxicolous. Lobes rounded, 5-12 mm wide, crowded, margins crenate, often ascending, ciliate, cilia sparse to conspicuous, 0.5-1.5 mm long, rather coarse. Upper surface matt, coriaceous, greenish-grey, often pruinose at lobe margins and becoming irregularly cracked, sorediate. Soralia marginal, linear to subglobose, soredia coarse, granular, white at first, becoming dark greyish-black. Lower surface black, with a naked, brown, marginal zone. Rhizines black, simple. Apothecia not seen. Chemistry: Cortex K+ yellow; medulla K-, C-, KC-, Pd-. Caperatic acid and atranorin.