Subcontinental xeric, thermophile grasslands of middle European collinar rock ledges, mostly dominated by the strong tufts of the glaucous Festuca pallens, Festuca sadlerana and Festuca pannonica and of the green Sesleria albicans, and with Dianthus gratianopolitanus, Carex humilis, Melica ciliata, Aster alpinus, Artemisia campestris ssp. lednicensis, Hieracium spp., Biscutella laevigata ssp. varia, Teucrium botrys, Teucrium montanum, Helianthemum canum, Iris aphylla, Allium strictum, Allium senescens ssp. montanum, locally distributed from French Jura and Rhine valley to sub-Pannonic foothils and Carpathians in Romania. The communities of the Festucion pallescentis often occupy isolated stations and include rare or relictual species which impart to many of them a distinctive biogeographical and physiognomic individuality. In particular, rare and highly disjunct western outposts occur in the Meuse basin of the Belgian and French Ardennes, harbouring, among others, very isolated populations of Draba aizoides var. montana, Artemisia alba ssp. saxatilis and Hieracium vogesiacum.