Placidium tenellum (Breuss) Breuss
Syn.: Catapyrenium tenellum Breuss
Lichenised.
Substrate: calciferous soil
Altitudinal distribution: submediterranean/colline belt (potential vegetation: mixed deciduous forests dominated by Quercus and Carpinus)
Note: a widespread but rare species of dry, very open grasslands and garrigues on calcareous substrata, extending eastward to Mongolia, with a single record from low elevations in the Western Alps (France).
