Thallus somewhat subcrustose centrally, closely appressed throughout or slightly raised at margins, moderately to tightly adnate, 2-9 cm diam., saxicolous. Lobes 0.3-1.5 mm broad, almost flat to strongly convex at apices, convex centrally, short and rounded to somewhat elongate, closely contiguous to subimbricate. Upper surface olive to yellow-brown or black-brown, paler at apices, ± smooth at periphery becoming wrinkled, fissured to subareolate centrally, mostly very dull, slightly shining at apices, without isidia. Lower surface dark brown to black, paler in some parts, especially when raised from substrate, smooth to wrinkled, dull to subnitid, lacking rhizines. Apothecia common, sessile, concave at first becoming plane to irregularly convex, 2.5-5 mm diam., margins entire. Ascospores ellipsoid or oval-ellipsoid 8.5-11 × 4.5-6 µm. Pycnidia common. Conidia acerose to subbifusiform, 5.5-9 × 1 µm. Chemistry: Cortex K-, HNO3+ dark blue-green; medulla K+ yellow to orange-yellow, C-, Pd+ red-orange. Protocetraric and fumarprotocetraric acids.