Open grasslands of the coussous still covering vast but dwindling expanses of the Crau (southern France) a fossil delta of the Durance, with Brachypodium retusum, Stipa capillata, Dichanthium ischaemum, Elymus caput-medusae, Thymus vulgaris, Bellis sylvestris, Asphodelus fistulosus, Euphorbia seguierana, Linum gallicum, Salvia multifida, Bufonia macrosperma; they support a fauna of exceptional originality.