Verrucaria slovaca Servít

Lichenised. Poorly known taxon.
Substrate: calciferous rocks
Altitudinal range: from the montane belt (potential vegetation: deciduous forests dominated by Fagus sylvatica and closed coniferous forests with Picea abies) to the subalpine belt (potential vegetation: open, taiga-like forests dominated by Larix decidua and/or Pinus cembra and Rhododendron)
Note: a species with a spreading, hemiendolithic, whitish thallus, finally hemispherically protruding ascomata (to c. 0.35 mm in diam.) often with a thalline annulus and separated by a cleft from the thallus, an adpressed involucrellum reaching down to the base of the perithecium, and oblong to ellipsoid ascospores (to c. 30 µm long); on rather shaded surfaces of calcareous rocks in Central Europe, with a few records from the Western Alps (France).
France: Alpes-de-Haute-Provence; Alpes-Maritimes;