A pioneer species of wet mud and shallow water, found in a wide variety of habitats including the edges of lakes, ponds, reservoirs, rivers, ditches, canals and backwaters. It also occurs in reedswamps and tall-herb fens, and readily colonises sand-, gravel-, clay- and marl-pits. It is shade-tolerant, and is found in swampy Alnus woods and Salix carr. Reproduction is by seed. Lowland.
An annual of moist, open disturbed ground around the margins of ponds and by ditches, often on ground subject to winter-flooding. The substrate may be peaty, muddy or stony but humus-rich. Seed may not be set in cool summers. Lowland.
A rhizomatous perennial herb of marshes and wet pastures near the coast, and sometimes in base-rich flushes on sea-cliffs. It also occurs on pond margins and in ditches inland, where it is usually planted. Reproduction is through vigorous rhizomatous spread, and it may not set seed in Britain. Lowland.