Protoparmeliopsis muralis (Schreb.) M. Choisy var. diffracta (Ach.) M. Choisy ex Werner

Syn.: Lecanora diffracta (Ach.) Ach., Lecanora muralis (Schreb.) Rabenh. var. diffracta (Ach.) Rabenh., Lichen diffractus Ach.
Lichenised. Poorly known taxon.
Substrate: siliceous rocks
Altitudinal range: from the submediterranean/colline belt (potential vegetation: mixed deciduous forests dominated by Quercus and Carpinus) 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 variety differing from typical P. muralis in having a black hypothallus visible between the areolae, not distinguished from P. bolcana by some authors, merged with P. muralis by others; on siliceous rocks in open situations, apparently widespread in Europe but not common; the distribution gaps in the Alps are probably virtual for the reasons given above.
France: Alpes-de-Haute-Provence; Haute-Alpes; Alpes-Maritimes; Isère; Haute-Savoie; Var;