Thallus ± orbicular, loosely attached, to 7 cm diam. Lobes dark leaden grey to bluish-black when wet, pale grey to faint greyish-blue when dry, 0.3-0.7(-0.9) cm wide, adjacent to somewhat imbricate, broadly cuneate to flabellate, apices rounded, margins ± entire or variously notched or incised, ± deflexed. Upper surface matt, minutely wrinkled, uneven, in parts minutely scabrid, with transverse, concentric ridges, isidiate. Isidia concolorous with thallus, laminal and marginal, at first granular, becoming terete, mainly simple, occasionally weakly branching, 0.01-0.15 mm diam., to 1 mm long, sparse in young lobes, becoming crowded in older parts. Lower surface pale, densely rhizinate. Rhizines pale, sometimes becoming bluish-grey or blackish, rarely visible beyond lobe margins, complex, entangled or arranged in distinct lines. Apothecia sparse to frequent, to 1.5 mm diam., disc concave at first becoming plane or convex with age, usually pale brown, sometimes blackened or dark with age, proper margin distinct (at least in young apothecia) usually pale, sometimes dark with age, occasionally with small, white, basal, projecting hairs, fruits closely surrounded by a ring of granular to terete or partly flattened isidia, forming a ± lobulate thalline margin. Ascospores 11-15 × 5-8 µm.