Calcareous cliff and rock communities of the Alps and the Carpathians, of lesser satellite ranges and of sub-Mediterranean areas of the northern Tyrrhenian periphery. Dominant species include ferns Asplenium ruta-muraria, Asplenium trichomanes, Asplenium viride, Cystopteris fragilis, Gymnocarpium robertianum, vascular plants (e.g.Saxifraga paniculata) and mosses.