Caloplaca arcis (Poelt & Vězda) Arup

Syn.: Caloplaca citrina (Hoffm.) Th. Fr. var. arcis Poelt & Vězda, Flavoplaca arcis (Poelt & Vězda) Arup, Frödén & Søchting
Lichenised.
Substrate: siliceous rocks
Altitudinal range: from the submediterranean/colline belt (potential vegetation: mixed deciduous forests dominated by Quercus and Carpinus) to the montane belt (potential vegetation: deciduous forests dominated by Fagus sylvatica and closed coniferous forests with Picea abies)
Note: a species of the C. citrina-group with thalli developing coarse blastidia in the centre, distinctly lobate at the margins, often with apothecia; on mineral-rich siliceous rocks and elsewhere also on calcareous rocks, also on man-made walls near settlements; widespread, but in the Alps poorly recorded, probably because it was not distinguished in the past.
Austria: Salzburg; Steiermark; Burgenland; France: Alpes-Maritimes; Vaucluse; Var;