Thallus appressed, tightly adnate, 2-6 cm diam., saxicolous. Lobes 1-3 mm broad, flat, elongate and discrete, mostly wider at or near tips and narrowing inwards. Upper surface dark brown or blackening, slightly paler and red-brown at apices, smooth or slightly pitted, shallowly fissured or wrinkled centrally, dull, subnitid at apices, without isidia. Lower surface black, slightly paler at apices, ± smooth, flat, dull, sparsely to moderately rhizinate. Rhizines simple, concolorous with lower surface, to 0.3 mm long. Apothecia common, sessile, concave at first becoming plane, margins entire. Ascospores 8.5-10.5 × 4.6 µm. Pycnidia common. Conidia 5.5-6.5 × 1 µm. Chemistry: Cortex K-, HNO3 dark blue-green; medulla K-, C-, KC- Pd-. ?Stenosporic acid.