Caloplaca nubigena (Kremp.) Dalla Torre & Sarnth. var. keissleri (Servít) Clauzade & Cl. Roux

Syn.: Blastenia keissleri Servít, Caloplaca keissleri (Servít) Poelt
Lichenised.
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 alpine belt (potential vegetation: treeless Alpine grasslands and tundras, to the lower limit of perennial snow and the equilibrium line of glaciers)
Note: a taxon with an endolithic thallus indicated by usually whitish patches and sunken orange apothecia with slightly concave discs and thin parathecial margins (somehow recalling Protoblastenia incrustans); on boulders and outcrops of limestone; fairly common at higher elevations in the eastern Mediterranean region; apparently more frequent in the Western Alps.
Austria: Vorarlberg; Tirol; France: Alpes-de-Haute-Provence; Alpes-Maritimes; Drôme; Vaucluse; Var;