This association includes vegetation on non-calcareous rock outcrops or stabilized but hardly soil-filled screes which contain the relict species Saxifraga rosacea. Most of these habitats are of natural origin and have been open for millenia. On some screes, this vegetation type occurs in places with streams of cold air emerging from the talus. It is found on several sites in northern and central Bohemia and very rarely in south-western Moravia.