Description: Thallus crustose, episubstratic, granular to irregularly areolate, dispersed or continuous, white to yellowish white, forming small patches. Apothecia distinctly lecanorine only when young, but soon appearing biatorine, sessile, 0.2-0.5 mm across, with a dark green, red-brown, olive-black or black (often piebald), strongly convex, epruinose disc, and a thin, smooth, soon excluded thalline margin. Epithecium yellowish brown to olive-green, with granules dissolving in K; hymenium colourless, 55-80 µm high; paraphyses branched and anastomosing, 2-2.5 µm thick, the apical cells only slightly swollen, up to 3.5 µm wide; hypothecium colourless. 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, narrowly ellipsoid, (10-)12-17 x 4.5-5.5 µm. Photobiont chlorococcoid. Spot tests: thallus K-, C-, KC+ faintly yellow, P-, UV+ pale orange. Chemistry: usnic acid, zeorin.
Note: on twigs of Calluna and other shrubs, more rarely on lignum and bark of coniferous trees and oaks. Closely related to L. symmicta, this species is included in the Italian red list of epiphytic lichens as “Endangered” (Nascimbene & al. 2013c).