Purple Loosestrife
Other Common Names: spiked loosestrife
(Lythrum salicaria)
Non-Native
Purple Loosestrife has woody, square stems with purple flowers at the ends.
Description
Purple loosestrife stems are four to ten feet tall, hairy, woody, and angled (four to six sides).
Leaves are green and sword shaped with a round or heart shape at the base and are whorled or paired around the stems.
Flowers are pinkish purple with five to seven narrow petals around a yellow center. There are many flowers along the top six to 12 inches of the flower spikes. Purple loosestrife blooms July through September. Because flowers bloom gradually on the stalk, seeds are produced and released for multiple weeks.
Every purple loosestrife plant can produce as many as 2.7 million seeds each year. The seeds are as small as grains of sand and thus easily spread by wind, water, animals, and humans. Loosestrife seeds often germinate right away, but they can lay dormant for multiple years before they sprout.
Purple loosestrife looks like native fireweed and blue vervain, which are beneficial wetland plants. Purple loosestrife grows aggressively and can crowd out native vegetation.
Management Options
Click here for more information on how to control purple loosestrife.
Location
Purple loosestrife can be found across the United States.
Propagation
seeds, rhizomes
Management Options
Click here for more information on how to control purple loosestrife.