Thallus ± appressed throughout or somewhat pulvinate, moderately to loosely adnate, 2-7 cm diam., saxicolous. Lobes 1-3 mm broad, ± flat, short and rounded to somewhat angular, contiguous to imbricate or entangled. Upper surface olive-brown to dark reddish-brown, often distinctly paler and yellowish at apices, ± weakly pitted apically, smooth or fissured centrally, dull throughout, shining at apices, isidiate. Isidia ± cylindrical, simple or branched, 0.1-1 mm long, 0.05-0.2 mm diam., often densely packed and ± contiguous centrally. Lower surface brown-black or black, paler at apices, ± smooth, dull or subnitid in part, moderately rhizinate. Rhizines concolorous with lower surface, to 1.2 mm long. Apothecia rare, sessile, strongly concave, to 5 mm diam., margins isidiate. Ascospores ellipsoid 9-11 × 5-6 µm. Pycnidia absent. Chemistry: Cortex K-, HNO3 + blue-green; medulla K-, C-, or ± slow yellow, KC+ red-dingy orange, Pd-. Glomelliferic, glomellic and loxodellic acids with traces of perlatolic and gyrophoric acids.