Umbilicaria subglabra (Nyl.) Harm.

Syn.: Agyrophora subglabra (Nyl.) M. Choisy, Gyrophora subglabra Nyl.; incl. Umbilicaria subglabra (Nyl.) Harm. var. schmidtii Frey
Lichenised.
Substrate: siliceous 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: on steeply inclined to horizontal, exposed surfaces of siliceous rocks, often at the top of large boulders; widespread throughout the Alps.
Austria: ?Vorarlberg; Tirol; Salzburg; Kärnten; Steiermark; Switzerland: Graubünden; Uri; Vaud; Valais; France: Alpes-de-Haute-Provence; Haute-Alpes; Alpes-Maritimes; Isère; Italy: Friuli; Trentino Alto Adige; Piemonte; Valle d'Aosta;