Purple loosestrife is an exotic weed in Illinois. The Illinois Exotic Weed Act prohibits the sale or distribution of this plant in Illinois. The plant is spread by seed. An individual plant can produce almost 23 million seeds in a single year. It commonly grows in wet areas such as shores, roadsides, and swamps. The plant is native to Eurasia, and today can be found throughout the entire United States. Purple loosestrife has rhizomes that aid the plant in reproducing far beyond its parent plant. It can become established quickly and form dense vegetative thickets that exclude nearby native plants.
As an alternative, swamp milkweed (Asclepias incarnata) is a plant native to the United States with a similar habitat and appearance. There are a number of native and non-native species that could be used in place of purple loosestrife. More desirable species may be found using the online Search Trees and Plants page of the Arboretum website. Before purchasing or planting, be sure to check for any local or state guidelines on this species, and ensure that this plant is suitable for its habitat by checking its attributes at mortonarb.org or plants.usda.gov.
- Family (English) Loosestrife
- Family (botanic) Lythraceae
