Description: Thallus foliose to subfruticose, almost monophyllous, often more thalli appearing together in colonies of small lobes radiating from the substrate. Lobes olivaceous to dark brown, wrinkled, rather glossy, flattened, rounded at apex, up to 10 mm long (usually less), 2-3 mm broad, smooth to wrinked; lower surface whitish or pale brown, with scattered, simple or slightly branched rhizines. Upper and lower cortex prosoplectenchymatous; medulla white, rather loose. Apothecia very numerous and often obscuring the lobes, lecanorine, submarginal to terminal, up to 3.5 mm across, with a reddish brown, glossy disc and a thick, smooth to crenulate margin often bearing scattered pseudocyphellae. Epithecium brown; hymenium and hypothecium colourless; paraphyses conglutinate. Asci 8-spored, thick-walled, the apex I+ blue with a wide, divergent axial body, Lecanora-type. Ascospores 1-celled, hyaline, ellipsoid, 6-10 x (3.5-)5-7(-10) μm. Pycnidia black, mostly marginal, slightly projecting. Conidia dumbbell-shaped (enlarged at both ends), 5-7 x c. 1 μm. Photobiont chlorococcoid. Spot tests: cortex and medulla K-, C-, KC-, P-, UV-. Chemistry: medulla with lichesterinic and protolichesterinic acid.
Note: a subarctic-subalpine, circumpolar species found near treeline on small twigs of shrubs and trees, especially Betula, Alnus viridis, Rhododendron ferrugineum, mostly near the ground and in areas with siliceous substrata; confined to the Alps in Italy and very rare in dry areas.