Altitudinal distribution: submediterranean/colline belt (potential vegetation: mixed deciduous forests dominated by Quercus and Carpinus)
Note: a rare species with a thick, brownish-grey thallus of convex to subspherical areoles (or conserving the shape of the host thallus) covered by a crystalline pruina, and ellipsoid ascospores (to c. 15 µm long); lichenicolous on Caloplaca arnoldii on calcareous rocks or schists containing some calcium; widespread in SW Europe, including a record from the Western Alps (France).
