An annual of hedge banks, waste places, arable fields and other cultivated ground. Lowland.
A biennial or monocarpic perennial herb found on sea-walls, beside brackish ditches, on tidal river banks and drift lines, and the uppermost parts of saltmarshes. Inland it occurs on disturbed ground in marshes, by ponds and ditches and occasionally in gravel-pits. Lowland.
This perennial herb occurs in permanent shallow water in streams, ditches, ponds, canals and backwaters, and in sites which are subject to periodic desiccation, such as the edges of lakes, pools, reservoirs and dune-slacks. It is confined to oligotrophic or mesotrophic habitats, and most sites are base-poor. Reproduction is by seed. 0?500 m (Cronkley Fell, N.W. Yorks.).
This perennial sterile hybrid is found in marshes and at the sides of lakes, rivers, streams and canals. Lowland.
A perennial herb, found in shallow water in streams, ditches, swamps and marshes, and on seasonally exposed mud at the edges of ponds, lakes, rivers and canals, sometimes scrambling into nearby vegetation. It is characteristic of nutrient-enriched sites. Generally lowland, but reaching 335 m E. of Shap (Westmorland).
A creeping perennial herb of damp meadows and shallow water in ditches and ponds, generally at sites subject to winter flooding. At Port Meadow (Oxon) it grows in disturbed, shortly-grazed neutral grassland and adjacent open soil, where trampling by horses and cattle keeps the habitat open. Seed is produced by plants that escape grazing. Lowland.