Mostly coarse, unstablized, dry, sunny calcareous screes of the montane and subalpine levels of the Alps and of the uplands and lowlands of Central Europe. Vegetation of alliances Stipion calamagrostis and Arabidion alpinae.
Calcareous screes of the Paris basin and its periphery, with Leontodon hyoseroides, Sisymbrium supinum, Linaria supina, Galeopsis angustifolia and many rare or endemic plants, including Viola hispida (endangered endemic), Galium timeroyi ssp. fleurotii, Iberis violetii, Iberis durandii, Biscutella neustriaca.