Description: Thallus crustose, endosubstratic or episubstratic and then warted-areolate, greenish yellow to ochre, the areoles 0.1-0.4 mm wide. Apothecia lecanorine, rounded, 0.4-1 mm across, sessile and constricted at base, with a reddish-brown, finely whitish-pruinose disc, and a prominent, persistent, not flexuose proper margin. Thalline exciple corticate, 75-110 µm wide laterally, 100-140 µm wide at base, cortex 5-20 µm wide in upper part, 16-40 µm wide in lower part, the medullary hyphae with 1-2 µm thick lumina; epithecium reddish brown, 5-15 µm high, N-; hymenium colourless or yellowish, 40-60 µm high; paraphyses simple or sparingly branched, c. 1 µm thick at mid-level; hypothecium colourless or yellowish, 40-90 µm high. Asci 8-spored, clavate, very thin-walled, with a K/I+ blue, tall tholus penetrated by a faintly amyloid apical cushion, the wall K/I-, surrounded by a blue outer layer, Lecanora-type. Ascospores 1-celled, hyaline, ellipsoid, 9-13 x 4.5-6 µm. Photobiont chlorococcoid. Spot tests: thallus K-, C-, KC- or KC+ faintly yellow, P-. Chemistry: isousnic and usnic acids.
Note: a species described from North America and also found on the mountains of central and southern Spain, mainly growing on the bark of Pinus; to be looked for in Italy.