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).
Usually open communities of the margins of Palaearctic lakes, rivers and brooks dominated by, or rich in, Butomus umbellatus, characteristic of strongly fluctuating still or slow-flowing base- and mineral-rich waters.