Very open formations colonizing, within the supra-Mediterranean steppe zone of the Causses (unit E1.51), local deposits of dolomitic sands, characterized by Armeria girardii (Armeria juncea), Arenaria aggregata, Helianthemum pilosum, Sedum ochroleucum, Alkanna tinctoria, Alyssum serpyllifolium, Helichrysum stoechas, Silene otites, Aster alpinus, Festuca christianii-bernardii, Corynephorus canescens, Phleum arenarium.