Mulligan (Agriculture Canada, Ottawa, retired)
Butomus umbellatus L., flowering rush, butome à ombelle Flowering rush is a perennial aquatic herb, with fleshy rhizomes, that grows 1 to 1.5 meters (3.3 to 5 feet) high. It can tolerate a water level up to 2 meters (6.5 feet) deep. It was introduced into this Continent from east Asia as an ornamental plant, and it is now found along the fresh water shores of lakes, ponds, and riverbanks in all northern States and in all provinces except Saskatchewan. Where present, it has the potential to be an invasive species displacing native riparian vegetation and presenting a serious obstacle to boat traffic. It was reported for the first time in North America at Laprairie Quebec in 1897 and by 1935 Marie-Victorin considered it to be the most dominant aquatic monocotyledon in the Montreal area. It continues to be spread by garden plantings and by other movements of plant fragments and seeds.