This type of riparian scrub is dominated by Salix purpurea, which is accompanied by other willow species, namely S. euxina, S. triandra and S. viminalis. It occurs rarely on gravelly and sandy accumulations of montane and submontane rivers, especially in the Šumava and Moravskoslezské Beskydy Mountains. This scrub develops on gravel bars in the floodplains after strong floods or on disturbed stream banks. During succession in the absence of strong disturbance it can be replaced by Alnus incana woodland.