Description: Thallus crustose, episubstratic, of scattered, small, yellow to greenish yellow, convex, 0.05-0.15 mm wide granules (sometimes confluent into 20-30 μm wide granules resembling blastidia), rarely forming a rimose-areolate crust, without a distinct prothallus. Apothecia lecanorine, yellow, 0.2-0.4 mm across, scattered to aggregated, with a flat to finally convex, bright yellow-pruinose disc and a persistent to excluded margin. Exciple with clusters of algae (5-10 μm diam.) in lower part; epithecium yellow-brown, granular; hymenium colourless, 60-70 μm high, I+ blue; paraphyses simple or sparingly branched, the apical cells not or only slightly swollen, 2-2.5 μm thick. Asci 16-32 spored, clavate, with an apical dome which is I+ blue only in the internal, lower part, interrupted in the centre by a a paler blue strip, Candelaria-type. Ascospores 1-celled, hyaline, globose, 4-5.5 μm in diam. Photobiont chlorococcoid, the cells 9–20 μm wide.Spot tests: thallus K-, C-, KC-, P-. Chemistry: pulvinic acid.
Note: a certainly rare epiphytic species, which is however widespread in Southern and Central Europe, with a single record from the Swiss Alps; to be looked for in Italy.