Communities of the margins of shallow lakes, rivers and brooks dominated by shorter, mostly non-graminoid helophytes emerging from mesotrophic or eutrophic, stagnant or slow-moving, shallow water, and constituting fringes or patches within or alongside reedbeds. Habitat structure is determined by one or two dominant species, e.g. Alisma spp., Oenanthe aquatica, Rorippa amphibia, Sparganium spp., Sagittaria sagittifolia, Equisetum fluviatile, Acorus calamus and Hippuris vulgaris (see subdivisions).
Formations of Sagittaria sagittifolia and Sparganium emersum of slowly flowing, and sometimes standing, meso-eutrophic waters of western Eurasia; formations of Sagittaria sagittifolia, Sagittaria natans and Caltha membranacea of similar eastern Asian waterbodies.