Purple loosestrife (Lythrum salicaria)

  • Purple Loosestrife Plant 215x150

Category A Weed

Loosestrife family (Lythraceae)

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    • 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


                Purple Loosestrife Infestation 215x150
                Purple Loosestrife Plant 215x150
                Mature Plant
                Purple Loosestrife Flower 215x150
                Purple Loosestrife Leaves Stem 215x150
                Leaves along stem
                  Nevada Noxious Weed Field Guide
                Nevada Noxious Weed Guide