Purple Loosestrife

Scientific Name:
Lythrum Salicaria
Identifying Characteristics:
Woody stalks with 4, 5, or 6 sides up to 2.4 meters tall and 1.5 meters wide
Purple flowers with 5-7 petals.
Leaves face opposite to each other, are 3-10 centimeters in length and have smooth edges.
Last seen:
This plant is native to Europe and Asia.
In Ontario it can be found around the Great lakes, the St. Lawrence River Basin, and towns such as Timmons, Geraldton, Sioux Lookout, and Rainy River.
First Offense:
Its first offense was in the early 19th century.
Known Accomplices:
Purple Loosestrife was likely introduced due to soil including its seeds being used to stabilize European ships sailing to North America, where the soil was later dumped.
Crimes Committed:
Can rapidly degrade wetlands, (the most biologically diverse ecosystem) which hundreds of North American bird, insect, fish, reptile, amphibian, plant and mammal species need to survive.
Quickly reproduce and have dense, web-like roots that choke out all other life.
About 190 000 hectares of North American wetlands, marshes, pastures, and riparian meadows are impacted yearly.
Attempts at Capture:
Government approved the release of two European leaf-consuming beetles, which are natural predators of the Purple Loosestrife, in 1992.
These beetles reduced Loosestrife populations significantly.


The Purple Loosestrife can clog irrigation canals and degrade farmland.
This species costs the government millions every year and the reward reflects the importance of its capture.

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