Description: Thallus crustose, episubstratic, granular, cracked-areolate or verrucose, usually thick and well developed, rarely thin and subimmersed, pale to dark grey. Apothecia abundant, sessile or somewhat immersed, 0.9-1.6(-2.5) mm across, 0.4-0.7 mm high, short cylindrical to lenticular, with a black mazaedium and a faint white pruina on the outer surface of the margin. Exciple brown, 80-170 µm thick laterally, of strongly sclerotized, interwoven hyphae, with an outer, 6-9 µm thick, gelatinous layer, strongly thickened at base (up to 450 µm high); hypothecium dark brown, up to 170 µm high, of periclinally arranged, sclerotized hyphae. Asci cylindrical, formed singly from hooked ascogenous hyphae, persisting until the spores are nearly ripe, with uniseriately arranged spores. Ascospores 1-septate, slightly constricted at septum, brown, broadly ellipsoid, 14-19(-21) x 8-11 µm, with an ornamentation of mainly longitudinally arranged, minute ridges in young spores, later disrupted by a few irregular cracks, the surface appearing striated. Pycnidia spherical to slightly flattened, semi-immersed in the thallus. Conidia simple, hyaline, cylindrical, 3-4 x 1 µm, tapering at one end. Photobiont chlorococcoid. Spot tests: thallus K+ yellow to reddish brown, C-, P-, P+ pale yellow or P+ yellowish red. Chemistry: placodiolic acid, plus sometimes a yellow, unidentified pigment, and other unidentified substances.
Note: a temperate to southern boreal-montane, circumpolar lichen found on old conifer stumps, more rarely on lignum of broad-leaved deciduous trees (especially Quercus and Castanea), and on wooden fence-posts, with optimum in upland areas. It is included in the Italian red list of epiphytic lichens as “Vulnerable” (Nascimbene & al. 2013c).