Description: Thallus inapparent, not lichenized, developing on bark of living trunks of Quercus. Perithecia black, half-immersed to superficial, (0.17-)0.2-0.25(-0.27) μm across, smooth, scattered singly or gregarious, pyriform, circular from above, sometimes laterally collapsed, with a central apical papilla laterally enlarged by stellate or sulcate structures. Exciple continuous, dark brown, becoming hyaline towards the centrum, 20-30 μm thick, of a textura angularis composed of thin-walled, isodiametric to elongated cells with subhyaline to dark brown walls. Paraphyses hyaline, smooth, thin-walled, septate, rarely branched, 1.5-3.3 μm thick, embedded in a I- gelatinous matrix. Asci 8-spored, cylindrical-clavate,, unitunicate, thin-walled, without a distinct apical apparatus. Ascospores 1-3-septate, hyaline, sinuous, sigmoid, semicircular to hook-shaped, (53-)65-93(-109) x (3-)3.5-4.5(-5) μm, thin-walled, smooth, with narrowly rounded ends, multiguttulate. Pycnidia scattered, black, slightly smaller than the perithecia (c. 0.1-0.15 mm across. Conidia 1-celled, hyaline, threadlike, (16-)18-23(-24) x (0.8-)0.9-1.1(-1.2) μm. Photobiont absent. Spot tests: all negative. Chemistry: without lichen substances.
Note: on bark of living trunks of Quercus known from Austria, Croatia, Czech Republic, Germany, Hungary, Poland, Sweden, and Switzerland; to be looked for in Italy.