Verrucaria ulmi Breuss

Lichenised. Poorly known taxon.
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: a species with a thin thallus forming small blackish patches, hemispherically protruding ascomata (to 0.35 mm in diam.) laterally covered by a thin thalline layer, a tightly adpressed involucrellum reaching the base of the perithecium, and ellipsoid ascospores (to c. 30 µm long); on bark of deciduous trees (e.g. Ulmus), with a few records, all from Central Europe, including the Eastern Alps (Austria).
Austria: Steiermark; Niederösterreich (incl. Wien);