Thallus to 2-3 cm diam., forming continuous smooth to granular patches, grey. Prothallus when present black. Soredia arising in ± circular, convex soralia, to 1 mm diam., farinose, pale yellow (to white in dried collections). Large crystal clusters occur in the thallus and are visible as translucent spots when the thallus is moistened. Anamorph: no information available. Teleomorph: ascomata apothecia, usually absent, to 0.8 mm diam., dispersed, immersed or sessile. Thalline exciple entire to delicately
crenulate, becoming excluded, including large crystal clusters. Discs pale green-, pink-brown or rarely almost black, flat. Epithecium pale yellow-brown interspersed with small granular crystals. Hymenium 35-60 μm tall. Interascal tissue of paraphyses, sparsely branched, apices not swollen or pigmented. Asci 45-50 × 10-15 μm. Ascospores (7-) 10-14 × (4-) 6-8 μm. Chemistry: thallus C–, K–, soralia sometimes weakly K+ yellow, Pd–, UV± pale orange (± atranorin, ± chloratranorin, 2-O-methylsulphurellin and usnic acid).