Purple Loosestrife
Scientific Name: Lythrum salicaria

History/Origin
          This native of Europe and Asia was first introduced in the early 1800's and most likely spread through the American interior by river-born traffic. The flower was purposefully brought into the Intermountain West as an ornamental for flowerbeds.

Biology/Ecology
          Purple loosestrife likes to have its feet (roots) wet. Seeds of this plant are spread by water and on the feet and bodies of birds and wetland animals. Seeds will often sink in the water, but upon germination the new seedlings float to the surface and take root where possible. These seeds usually germinate in such high densities that they suppress native plant seedlings. After flowering the standing plant stalks die leaving only the woody roots alive. These dead seasonal stalks can remain standing for 2 years. New seasonal growth sprouts up among the dead stalks, from both the root crown and along rhizomes, creating a densely grown stand of living and dead stalks.

Known Impacts
Detrimental:
          The dense stand of plant roots and stalks, impedes water flow and can clog irrigation canals and wetland channels, reducing the amount of open water for waterfowl. These same stands often crowd out over 50% of the native vegetation. Desired plants such as cattails and bullrush are overrun, creating a shift in wildlife habitats that affects predator/prey relationships, eliminates nesting sites, and generally reduces vertebrate and invertebrate populations.

Beneficial:
           The flowers of this plant are beautiful and are often used in ornamental flower beds. It was also used as a medicinal herb by early settlers of America.

Potential Locations
           Purple Loosestrife often grows in association with cattails and other wetland plants. These areas include streams, canals, ditches, shorelines of shallow ponds, and many other areas with moist soil.

Control/Management
• Herbicides are the best know tool for removing this plant(example herbicides: Escort, Roundup Ultra, Arsenal, Velpar [look at herbicide label: free search]).
• Education should be a top priority. If it is considered just another pretty "wildflower", people will not act or even understand the need for control measures.
• Present bio-control agents can slow down the spread, but do not eradicate the weed.
• Hand pulling or other physical manipulation has little or no effect because of the rhizomes.

NAPIS : biological control (maps)
Other Links