The alliance Ranunculion aquatilis includes aquatic vegetation of shallow, often periodical, still or slowly moving water with significant fluctuations of water table during the season. In summer water table can drop below the level of the bottom in some habitats. Dominant species can occur in different growth forms depending on water depth. They include various species of Batrachium, Callitriche, and Hottonia palustris. Depending on water depth, the dominant species are accompanied by various aquatic or wetland plants. This vegetation occurs mainly in natural habitats such as alluvial pools and oxbows, but it may also occur in man-made habitats if they are in an early successional stage or affected by frequent disturbance, which limits otherwise competitively stronger species of aquatic macrophytes. The alliance Ranunculion aquatilis is most common and diverse in north-western and central Europe and becomes increasingly rare towards the south and east.