Calaminarian grassland

Open formations colonizing heavy metal soils, either natural or resulting from past mining operations, in rapid regression and limited to a few stations in eastern Belgium, western Rhineland, Westphalia and Lower Saxony, and to one station in the southern Netherlands, with outposts in northern France, comprised of a highly specialised flora with the endemics [Viola calaminaria], [Viola guestphalica], [Thlaspi caerulescens] ([Thlaspi alpestre ssp. calaminare]) and [Festuca aquisgranensis] ([Festuca ophioliticola ssp. calaminaria]), with [Minuartia verna var. hercynica], [Silene vulgaris ssp. humilis] and [Armeria halleri], limited to this formation and the next, and with the steppic, central European [Festuca valesiaca].