This vegetation type, dominated by Spergularia rubra, occurs along forest roads, on sidewalks, playgrounds, roadsides and around railway stations. Soils are sandy to rocky, poor in bases and humus; in comparison with the Herniarietum glabrae they usually contain coarser particles. They can dry out considerably during the summer drought periods. The vegetation has its phenological optimum in mid-summer and early autumn. It occurs in colline to submontane areas of the Bohemian Massif.