This marsh type, dominated by Carex acutiformis, occurs in mesotrophic to eutrophic wetlands such as littoral zones of fishponds, oxbows, alluvial pools, river banks, floodplains of small streams, ditches, depressions in wet meadows and canopy openings in alder carrs. The soil is base-rich, organic or mineral, and it is wet or inundated with up to 5 cm deep water for most of the year. Occurrences of this association are concentrated in lowlands and warm colline areas of the Czech Republic.