In the phytosociological survey we sampled 11,477 individuals corresponding to 49 species, of which the most abundant species were Bacopa monnieri (4427 individuals), Salvinia auricu-lata (2275), Hydrocotyle bonariensis (2159) and Paspalum vaginatum(1084) (Table 2). The absolute density of the community was164 plants per square meter. The most frequent species wasNymphoides indica, recorded in 35 (50%) plots. S. auriculata, Hydro-cotyle bonariensis, Paspalum vaginatum, Echinodorus subalatus and Ludwigia leptocarpa were other frequently occurring species, andwere recorded in more than 20% of the plots, while 19 species were sampled in a single plot and five species only in two plot (Table 2).