Syn.: Verrucaria nigrescens Pers. var. acrotella sensu Anzi non Verrucaria acrotella Ach.
Lichenised. Poorly known taxon.
Substrate: calciferous rocks
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 calcicolous species with a brown-black, spreading, minutely rimose to areolate thallus, the areolae with a rough to pulverulous surface, a medulla with dark brown patches, hemispherically protruding ascomata covered by a thalline layer (to 0.3 mm in diam.), an involucrellum reaching down about half of the perithecium, and ellipsoid ascospores (to c. 30 µm long); known from a few localities in the Eastern Alps (Italy).
