Xero-thermophile medio-European and Atlantic forests on calcareous, often superficial, soils, usually of steep slopes, with a generally abundant herb and shrub undergrowth, characterized by sedges (Carex digitata, C. flacca, C. montana, C. alba), grasses (Sesleria albicans, Brachypodium pinnatum), orchids (Cephalanthera spp., Neottia nidus-avis, Epipactis leptochila, E. microphylla) and thermophile species, transgressive of the Quercetalia pubescenti-petraeae. The bush-layer includes several calcicolous species (Ligustrum vulgare, Berberis vulgaris) and Buxus sempervirens can dominate.