Cluster analysis of relevés of aquatic vegetation (cover data, Chord distance, UPGMA): 1, Lemnetum minoris; 2, Ceratophylletum demersi; 3, Lemnetum trisulcae; 4, Potamo perfoliati-Ranunculetum fluitantis; 5, Ranunculo trichophylli-Callitrichetum polymorphae; 6, Parvopotamo-Zannichellietum palustris; 7, Hippuris vulgaris f. fluviatilis community; 8, Veronico beccabungae-Callitrichetum stagnalis; 9: Potametum lucentis; 10, Potamo crispi-Myriophylletum verticillati; 11, Ranunculo circinati-Elodeetum nuttallii; 12, Potametum pectinati; 13, Potamo crispi-Ranunculetum trichophylli; 14, Ranunculo circinati-Myriophylletum spicati; 15, Potametum pusilli; 16, Nymphaeetum albo-luteae.