Description: Thallus squamulose to subcrustose-placodioid, bright yellow-green, sometimes with brownish patches, very thick. Squamules convex, contiguous, wrinkled, to 3 mm broad, the marginal ones to c. 1 cm long, developing on a black prothallus. Upper surface inspersed with yellowish granules, later covered by a thick epinecral layer; lower surface black, attached by numerous bundles of black rhizinoids. Apothecia frequent, lecideine, rounded, sessile, up to 2 mm across, developing among the squamules, with a black, flat to convex disc, and a thin, indistinct, concolorous proper margin. Exciple soon excluded, dark reddish brown; epithecium dark olive-green to blackish, K , N+ pale red; hymenium colourless, I+ blue; paraphyses anastomosing, densely branched, not or slightly thickened above; hypothecium dark. Asci 8-spored, clavate, with a I+ blue outer gelatinous coat, thickened at apex, with an internal I+ deep blue cap. Ascospores 0-1(-3)-septate, the central septum with an internal torus, brown, ellipsoid with rounded ends, 12-18 x 7-10 μm. Photobiont chlorococcoid. Spot tests: thallus K , C , KC , P+ yellow-orange, UV+ orange. Chemistry: rhizocarpic acid.
Note: an arctic-alpine, probably circumpolar lichen found on acid soil rich in humus and over bryophytes in fissures of siliceous rocks in cold, perennially humid situations above or near treeline; restricted to the Alps in Italy.
Growth form: Foliose, broad lobed
Substrata: soil, terricolous mosses, and plant debris