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Invasive Species: Purple Loosestrife

Invasive Species: Purple Loosestrife

Purple Loosestrife

(Lythrum salicaria)
*Established in Michigan*

RESTRICTED 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

 

Identification:

  • 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.

purple loosestrife
Photo courtesy of Linda Wilson, University of Idaho, Bugwood.org.

purple loosestrife
Photo courtesy of John D. Byrd, Mississippi State University, Bugwood.org.

purple loosestrife
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.

MORE INFORMATION:

Purple Loosestrife Invasive Species Alert - Printable PDF

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.