Siliceous cliff and rock communities of the thermo-Mediterranean, mesomediterranean and lower supra-Mediterranean levels of Provence, Corsica and eastern Spain, mostly constituted by ferns, in particular, of genus Cheilanthes (including Cosentinia) in xeric sunny situations, of genera Asplenium and Polypodium in more shady locations, accompanied by species of genus Dianthus, in particular, Dianthus sylvestris ssp. siculus, Dianthus sylvestris ssp. godronianus.