This is a species-poor vegetation type dominated by Calla palustris. It occurs in mesotrophic to dystrophic habitats such as pools in alder carrs, fishpond littoral zones with peat accumulation and ditches. Occasional records are also from eutrophic habitats such as ponds in the centres of village squares. It is typical of advanced stages of terrestrialization, but C. palustris stands can also float on the water surface in littoral zones, which significantly contribute to accumulation of organic sediment. This community is distributed in precipitation-rich, moderately warm to cool colline and submontane areas of the Czech Republic.