Lythrum salicaria

Plants

purple loosestrife, purple loosestrife or lythrum, purple lythrum, rainbow weed, salicaire, spiked loosestrife

Lythrum salicaria (Purple Loosestrife) is native to Eurasia from central Scandinavia to the Mediterranean, the northwest Mediterranean coast of Africa, portions of central Asia, China and Japan (Thompson et al. 1997). This plant may have been imported very early as a medicibal herb or ornamental (Thompson et al. 1987). Early records in North America are vague as to location of occurrence. The first herbarium specimen is from New Bedford MA, in 1831. Gray (1848) gave its range as Mains, Massachusetts, New York, and Canada and considered it native. Lythrum salicaria reached Philadelphia by 1852. By 1900, it had spread westward to the Great Lakes, and southward to Delaware, the District of Columbia, and North Carolina. Isolated West Coast populations were found in Washington by 1931 and Califonria by 1948 . Solid ballast from coastal and transatlantic shipping, canals, roads, and railroads, as well as escape from cultivation, were all probable means of transport. Many separate introductions are likely (Stuckey 1980; Thompson et al. 1987). As of 1985, records of L. salicaria were still strongly concentrated in the Northeast, with scattered records in the west to San Francisco.   Elsewhere in the world, Lythrum salicaria has been introduced to Australia, New Zealand, and Tasmania. This plant is widely regarded as invasive, dominating wetlands numerically and visually, with their purple flowers. Different methods of controll were attempted to try to maintain native biodiversity, wildlife food, and rare species.

 A bioontrol program, under the auspices of the Agricultural Research Service of the United States Department of Agriculture (USDA-ARS) and the United States Fish and Wildlife Service (USFWS), began with a study of insect herbivores which control L. salicaria in Europe.  Four species of beetles, including Galurcella calmariensis, G. pusilla, Hylobius transversovittatus, and Nanophyes marmoratus were released in freshwater wetlands across the United States, with the intention of attacking the leaves, roots and seeds of the plant.  Between 1993 and 1996, millions of these beetles and their  congener G. pusilla were released in at least 30 states and 3 province. his program, under the auspices of the Agricultural Research Service of the United States Department of Agriculture (USDA-ARS) and the United States Fish and Wildlife Service (USFWS), began with a study of insect herbivores which control L. salicaria in Europe.  Four species of beetles, including G. calmariensis, G. pusilla, Hylobius transversovittatus, and Nanophyes marmoratus were released in freshwater wetlands across the United States, with the intention of attacking the leaves, roots and seeds of the plant.  Between 1993 and 1996, millions of these beetles and their  congener G. pusilla were released in at least 30 states and 3 provinces. The goal of the Purple Loosestrife biocontrol program was not eradication, but reducing the dominance of L. salicaria, and restoring diversity in wetlands. This biocontrol program is considered largely successful (Endriss et al. 2019).