These alpine grasslands, supported by siliceous bedrocks, are dominated by the tussock-forming grasses Festuca supina and Avenella flexuosa. They have a rich lichen component. The association occurs on wind-exposed ridges and slopes from the timberline at approximately 1250 m to the highest summits of the Czech mountains. The soils are regularly disturbed by freeze-thaw cycles and aeolian erosion. Most stands are found in the Krkonoše Mountains, but several of them also occur in the Hrubý Jeseník and Králický Sněžník Mountains.