Information Last Reviewed June 2007
Family: Lythraceae
Symbol: LYMI
Home Range/U.S. Introduction:
This species is naturalized from Europe, first reported in the U.S. along the northeast coast in the early 1800s. Due to its attractive flowers, it has been planted as an ornamental garden species and has escaped from cultivation; it is now in at least 40 states and Canada.
U.S. Range Map:
Species Description:
Plants are erect, emersed, much-branched perennials, glabrous to often pubescent, growing to 1 m tall. The stems are 4-angled. The leaves are opposite or whorled, sessile, mostly longer than the internode above, 2-10 cm long, 0.5-1.5 cm wide, the base obtuse to cordate. The flowers are whorled in showy terminal bracteate spike-like inflorescences. The 6 petals are rose-purple, to 10 mm long. There are usually 12 stamens.
Growth Characteristics:
Plants grow in marshes, lakes, along river margins, wet meadows, prairies, and ditches. It is estimated that one plant may produce 2.5 million seeds.
Problems:
Often populations have spread so aggressively that native vegetation is excluded. Several garden races, some with larger rose-red petals, have been produced from this species and are cultivated. It is estimated that 200,000 ha of wetlands in the U.S. are lost annually through invasions of this species.
References:
Malecki, R. A., B. Blossey, S. D. Hight, D. Schroeder, L. T. Kok, and J. R. Coulson. 1993. Biological control of purple loosestrife. Bioscience 43(10):680-686.
Stuckey, R. L. 1980. Distributional history of Lythrum salicaria (purple loosestrife) in North America. Bartonia 47:3-20.
Thompson, D. Q., R. L. Stuckey, and E. B. Thompson. 1987. Spread, impact, and control of purple loosestrife (Lythrum salicaria) in North American wetlands. U.S. Fish and Wildlife Research Report 2.