Mycomicrothelia melanospora (Hepp) D. Hawksw.

Syn.: Microthelia koerberi Trevis., Microthelia atomaria auct. non (Ach.) Körb., Pyrenula melanospora Hepp, Verrucaria cinerella Flot. ex Zwackh nom. inval.
Non- or doubtfully lichenised.
Substrate: bark
Altitudinal range: from the submediterranean/colline belt (potential vegetation: mixed deciduous forests dominated by Quercus and Carpinus) to the montane belt (potential vegetation: deciduous forests dominated by Fagus sylvatica and closed coniferous forests with Picea abies)
Note: an apparently non-lichenised species with subepidermal ascomata, a dark brown involucrellum, dark brown 1-septate ascospores (13-16 × 6-8 µm) with more or less equal cells and a thin, coarsely verruculose perispore; on the smooth bark of deciduous trees, especially Mespilus germanica; rare throughout Europe; in the Alps only recorded from Austria and Italy.
Austria: Salzburg; Italy: Piemonte;