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Invasive Species: Purple Loosestrife
*Established in Michigan*
Report this species:
Use the Midwest Invasive Species Information Network (MISIN) online reporting tool
- Or - download the MISIN smartphone app and report from your phone - MISIN.MSU.edu/tools/apps/#home
- Perennial herb with a woody, square stem covered in downy hair.
- Height varies from 4 to 10 feet.
- Leaves are arranged in pairs or whorls.
- Magenta flower spikes with 5-7 petals per flower are present for most of the summer.
Photo courtesy of Linda Wilson, University of Idaho, Bugwood.org.
Photo courtesy of John D. Byrd, Mississippi State University, Bugwood.org.
Photo courtesy of Steve Dewey, Utah State University, Bugwood.org.
Habitat: Purple loosestrife thrives along roadsides and in wetlands. While seeds can germinate in water, establishment is much more successful in moist substrate that’s not flooded. It prefers full sun, but can tolerate shade.
Native Range: Europe and Asia.
U.S. Distribution: Purple loosestrife has been introduced to every state except Florida.
Local Concern: Given the right conditions, purple loosestrife can rapidly establish and replace native vegetation. This can lead to a reduction in plant diversity, which reduces habitat value to wildlife.
Other Common Names: Purple lythrum, rainbow weed, salicaria, spiked loosestrife.
MDARD Weed Risk Assessment for Purple Loosestrife (Lythrum salicaria) - This document evaluates the invasive potential of the plant species using information based on establishment, spread and potential to cause harm.