Comments: L. salicaria is native to Eurasia and was first reported from the northeastern coast of North America in 1814, (Stuckey 1980). Although purple loosestrife occurs in nearly all sections of the United States, the heaviest concentrations are in the glaciated wetlands of the northeast. Occurrences west of the Mississippi River appear to be scattered (Stuckey 1980), with the species establishing in reclamation projects in the west (Thompson and Jackson 1982).

Purple loosestrife is found in wetlands such as cattail marshes, sedge meadows, and open bogs. L. salicaria also occurs along stream and river banks and lake shores. In addition, the plant is found in ditches and other disturbed wet soil areas.

L. salicaria grows best in high organic soils, but tolerates a wide range of soils including clay, sand, muck, and silt (Thompson and Jackson 1982). Generally, the plant is found in full sun, but it can survive in 50% shade (Thompson and Jackson 1982). Typical associates include Typha latifolia, T. glauca, Phragmites australis, Spartina sp., Scirpus spp., and Carex spp. (Thompson and Jackson 1982).