Description: Perennial rhizomatous with erect stems, 2 - 6 feet. Leaves lance-shaped, simple, entire, and opposite or whorled. Flowers rose-purple, with 5 - 7 petals, less than 1/2 inch long, arranged spike-like and terminal on the stem.
Habitat: Usually associated with moist or marshy sites, ponds, meadows, ditches, and streambanks. Infestation can become dense and impede water flow in canals and ditches. Native to Europe. Introduced and cultivated as an ornamental.
Distribution: The largest known infestation of purple loosestrife in northeastern California is north of McArthur (Shasta Co). There are smaller sites at Tulelake and the Lower Klamath National Wildlife Refuge (Siskiyou Co) and near Reno, NV, along the Truckee River (Washoe Co).
Flowering Period: August to September