• Purple Loosestrife Plant 215x150

Category A Weed

Loosestrife family (Lythraceae)

Helpful Links

List of all Photo Credits

Purple loosestrife (Lythrum salicaria)


    • Up to 6 ft. tall, 4-5 sided, covered with short hairs and often branched; multiple stems arise from root crown


      • Mostly opposite or whorled, narrow to lance-shaped, 2-6 in. long, smooth edges (margins), lack hair (glabrous) to hairy; NO leaf stems (petioles)


        • Showy; clustered on stalks at the tips of branches; 5-7 pink to purple petals surrounding a yellow center; petals are less than 0.5 in. long, each have a dark (midvein) and appear wrinkled or crushed


          • Taproot with some spreading roots; can associate with nitrogen-fixing bacteria


            • Grows best in wet areas; often found in marshes and along the edges of pond and waterways; known to occur in Carson City, Churchill, Clark, Douglas, Elko, Storey and Washoe counties

            • Perennial; reproduces by seed and stem fragments

            • Historically used as an ornamental plant but has escaped cultivation


              • Repeated hand-removal of individual plants (including roots) can be effective; DO NOT mow

              • Several biological control agents are available

              • Apply metsulfuron to actively growing plants, glyphosate or triclopyr at bloom; imazapyr from bloom until killing frost