Description: Thallus crustose, episubstratic, dull green, rarely with a brownish tinge, granular or minutely squamulose, the granules (0.03-)0.04-0.12 mm in diam., often coalescing into a verrucose crust, the squamules, when present, flattened to convex, often minutely lobulate, up to 0.24 x 0.1 mm, adpressed to ascending (especially when developing on mosses). Cortex of rounded to angular cells, a few of them with up to 1.7 µm high papillae. Perithecia black, including the ostiolar region, half to three-quarters immersed amongst the thalline granules, globose when young, later pear-shaped, 0.14-0.2 mm across, the upper part roughened with vertical furrows. Exciple 2-layered, pigmented in outer part, colourless and of compressed cells within; involucrellum absent; hamathecium of periphysoids which soon dissolve into a poorly differentiated hymenial gel (interascal filaments in mature ascomata lacking). Asci 8-spored, clavate, thin-walled, fissitunicate, not or very weakly thickened above, I-, K/I-. Ascospores muriform, hyaline, ellipsoid to rarely subglobose, 20-46 x 12-20 µm. Photobiont chlorococcoid,the cells 5-10 µm wide. Spot tests: K-, C-, KC-, P-, UV-. Chemistry: without lichen substances.
Note: mainly on bark among mosses and on mossy rocks in rather humid and shaded situations. The species is apparently widespread in Central Europe; the Italian sample, from the bark of Q. coccifera, extends its distribution to the Mediterranean region.