The native habitats of this perennial herb are damp woodland, ditches, stream and river banks, where it occurs in both shaded and open situations. As an alien, it occurs on roadside verges, waste ground and other disturbed sites. Generally lowland, but reaching 335 m in Mid Perth.
This species has long been considered introduced to Ireland, Wales and most of England. In Scotland too its native status is sometimes questioned, partly in view of its late discovery (1777), and the limit of any native range has been obscured by escapes. There is no significant change in its presumed native distribution since the 1962 Atlas, though alien records are much more frequent in England.
European Temperate element.
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