Since its first North American record (perhaps 1845 in R.I.), this Europaean species has spread slowly into northeastern states and adjacent Canada, especially the Great Lakes region (SERNEC 2024; K). It has recently been reported from W.Va. (W) and e. Ky. (V. Voelker/NP, pers. comm.). It is common across most of Britain: "A perennial herb of wetland habitats, such as marshes, fens and streamsides, especially where disturbed, as well as man-made habitats, such as gardens, cultivated and waste ground, quarries, streets and other urban localities. It has a wide ecological tolerance, occurring in both wet and dry, acidic and basic, eutrophic and nutrient-poor conditions; and plasticity may result in plants of very different appearance in each" (BSBI 2022; plantatlas2020.org/atlas).