Physcia tribacia (Ach.) Nyl.

Syn.: Lecanora tribacia Ach., Physcia erosa (Borrer) Leight.
Lichenised.
Substrate: intermediate rocks (such as calciferous schists), , lignum
Altitudinal range: from the mesomediterranean belt (potential vegetation: evergreen broad-leaved forests dominated by Quercus ilex) to the montane belt (potential vegetation: deciduous forests dominated by Fagus sylvatica and closed coniferous forests with Picea abies)
Note: a widespread Mediterranean to xeric subtropical lichen found on basic siliceous rocks in sunny situations, often with Peltula euploca and ecologically related species, but less bound to periodical seepage of water; widespread in the Alps, being most common in the dry Alpine valleys.
Austria: Vorarlberg; Tirol; Salzburg; Kärnten; Steiermark; Switzerland: Bern; Graubünden; Schwyz; Ticino; Vaud; Valais; France: Alpes-Maritimes; Savoie; Var; Italy: Veneto; Trentino Alto Adige; Lombardia; Piemonte; Valle d'Aosta;