Thallus foliose, closely appressed, rosette-forming, to 8 cm diam., saxicolous, rarely on glass. Lobes broad (to 6 mm wide), rounded, margins very shallowly incised. Upper surface yellowish-green, wrinkled, shining, isidiate centrally, maculate and soredia absent. Isidia simple, terete, becoming coralloid-branched, laminal, often dense, forming a ± areolate crust, sparse at margins. Lower surface black, wrinkled, with a naked, brown, marginal zone. Rhizines black, simple, central. Apothecia and pycnidia not seen. Chemistry: Cortex K-; medulla K+ yellow, C-, KC-, Pd+ orange. Stictic and usnic acids.