The association Phalaridetum arundinaceae includes dense stands of reed canary grass, Phalaris arundinacea, occurring in complexes of marsh vegetation in lowland river floodplains and in the littoral zones of still water bodies. It occurs in shallow depressions, oxbows in an advanced stage of terrestrialization, along ditches with slow-moving water or on the banks of flooded sand pits. In contrast to the association Rorippo-Phalaridetum arundinaceae, habitats of Phalaridetum arundinaceae are flooded longer, remain constantly wet, are not directly affected or disturbed by currents, and grow on fine-grained sand or silt. Strong accumulation of litter contributes to the development of organic soil. This association can also occur in floodplains of middle river courses, where it grows in depressions that are distant from the river channel. In the Czech Republic this vegetation type is common from lowlands to mid-altitudes.