This is an open vegetation type of rock outcrops with the prostrate perennial herb Scleranthus perennis and drought-adapted acrocarpous mosses Ceratodon purpureus and Polytrichum piliferum. It is confined to very shallow soils disturbed by erosion and in some places also by trampling. It occurs in moderately dry areas of the Bohemian Massif, particularly in central and southern Bohemia and south-western Moravia.