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Spotted Knapweed

Photo by Rob Routledge, Sault College

Common Name: Spotted knapweed
Scientific Name: Centaurea maculosa
Origin: Europe and Asia


The spotted knapweed is a biennial or short-lived perennial herbaceous plant. With grayish leaves and pink to purple thistle-like flowers, this plant grows to be 2 to 3 feet in height. Flowering occurs from July through September.


Often found in artificial corridors, gravel pits, agricultural margins, and overgrazed pastures. The plant prefers open habitats with full sun and can grow in nutrient pool soils and dry conditions.


This plant is able to spread rapidly, outcompeting native plants. The spotted knapweed is also poisonous to other plants. Because the plant is able to grow so rapidly, it often becomes a problem in pastures and agricultural fields.


Consistent mowing and pulling may be effective as it prevents seed dispersal. For larger infestations, herbicides and prescribed burning can be used.

Distribution: View Map

The spotted knapweed is found throughout the United States and is present in the FL-PRISM.

Invasive Rank