Verrucaria andesiatica Servít

Lichenised.
Substrate: ,
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 very thin, epilithic, olive-brown thallus, ascomata (to 0.5 mm in diam.) in convex to conical warts, with a superficially spreading, carbonised involucrellum, and oblong to ovoid ascospores (to c. 30 µm long); on moist siliceous rocks from the lowlands (type!) to treeline; widespread in Europe but very rarely collected.
Switzerland: Schwyz; France: Alpes-Maritimes;