Thallus closely appressed, rather tightly adnate, 2-3 cm diam., saxicolous. Lobes 1-3 mm broad, flat, elongate and discrete, mostly distinctly wider at ends and narrowing towards centre. Upper surface dark red-brown or blackening, paler and more yellow-brown at apices, smooth to weakly pitted at apices, becoming fissured and weakly wrinkled centrally, dull, slightly shining at apices, without isidia. Lower surface black, paler at apices, flat, smooth and ± dull, moderately rhizinate. Rhizines concolorous with lower surface, to 0.2 mm long. Apothecia not seen. Pycnidia common. Conidia bifusiform, 5-6 × 1 µm. Chemistry: Cortex K-, HNO3+ dark blue-green; medulla K-, C-, KC+ rose fading, Pd-. Glomelliferic acid.