This vegetation type is dominated by Persicaria amphibia, which forms usually open stands with leaves floating on the water surface. It occurs in mesotrophic to eutrophic water bodies with still or slowly moving water, e.g. at the margins of fishponds and water reservoirs, in fish storage ponds, flooded sand pits, channels, oxbows and other types of alluvial pools, and lentic sections of streams. It is associated with both early and late stages of terrestrialization. The dominant species is well adapted to habitat desiccation; in such conditions, it occurs in a terrestrial growth form. Localities of this association are scattered across the Czech Republic from the lowlands to mountain areas.