Description: Thallus crustose, whitish to pale brown, poorly evident, not lichenized. Perithecia black, 0.2-0.4 mm across, circular or ellipsoid, Involucrellum of compacted hyphae and often with minute fragments of bark cells, K+ yellowish brown; hamathecium of persistent, much branched, 1.5-2.5 μm thick paraphysoids; hymenial gel I-. Asci obpyriform, with an apically much thickened wall, 65-105 x 20-40 μm. Ascospores 1(-3)-septate, the upper half wider than the lower one, at first hyaline, then turning brownish and verruculose, sole-shaped, 27-40 x 8-13 μm, without a distinct perispore. Pycnidia usually abundant, black, c. 0.1 mm across. Conidia bacilliform, 4-6 x c. 1 μm. Photobiont absent. Spot tests: all negative. Chemistry: without lichen substances.
Note: an early coloniser of smooth bark, especially on twigs of broad-leaved trees and shrubs (e.g. Corylus and Fagus), in humid deciduous woodlands.
Growth form: Fungus
Reproductive strategy: mainly sexual
Most common in areas with a humid-warm climate (e.g. most of Tyrrenian Italy)