Thallus squamulose, ± forming rosettes, closely appressed to the substrate. Squamules 2 × 2-3 mm, extended to 5 mm at the margins. Upper surface fragile, pale red-brown to smoke grey-brown, smooth or scabrid matt. Soralia predominantly marginal, sometimes also laminal, coarse, knob-like, at first concolorous, sometimes breaking down into a ± uniform surface of coralloid blue-grey granules which may become coarsely cracked-areolate. Hypothallus blue-black, fimbriate, sometimes apparent between cracks but seldom extending beyond the squamules. Photobiont Nostoc. Anamorph: not known. Teleomorph: ascomata apothecia, 1-1.5 mm diam., rare. Disc red-brown, flat. Thalline exciple absent, true exciple rather thick, paler, persistent. Interascal tissue of unbranched paraphyses, not or slightly thickened at the apices, the pigment external, I+ blue. Asci 8-spored, apical apparatus a deeply K/I+ blue staining ring structure. Ascospores 16-20 × 9-10 μm, hyaline, ellipsoidal, without an epispore.