Description: Thallus crustose, not lichenized, continuous, endosubstratic, whitish, smooth, dull. Perithecia hemispherical or slightly elliptical, black, c. 0.4-1 mm across, not covered by thallus. Exciple thin, in upper half clypeus-like, bluish-black to violet-brown; involucrellum dark brown, mingled with bark cells; hamathecium of persistent pseudoparaphyses anastomosing above the asci, c. 1 μm thick, not inspersed with oil droplets; hymenial gel non-amylod. Asci 8-spored, cylindrical to clavate, thick-walled, the inner wall thickened towards apices, with a shallow, broad ocular chamber. Ascospores at first 3-septate then submuriform to muriform, hyaline, long ellipsoid to clavate, (15-)17-21(-23) × (6-)7-10(-11) μm, with 4-6 transverse septa and 1-2 longitudinal septa. Pycnidia black. Conidia 3-septate, brown, 9-12 x 3-4 μm. Photobiont absent. Spot tests: all negative. Chemistry: without lichen substances.
Note: a rare species growing on smooth bark, especially of Betula.