Spotted knapweed
(Centaurea biebersteinii)
General description:
Herbaceous, short-lived perennial, 2-4’ tall. Persists as a rosette 1-4 years before bolting. Flowering plants usually have 1-6 stems, but many have up to 20.
Ecological threat:
- Invades dry areas, including prairie, oak and pine barrens, dunes, and sandy ridges. It also invades roadsides and disturbed areas.
- Roots exude allelopathic chemicals (compounds that inhibit the growth of other vegetation).
- It is not palatable as a forage plant and is avoided by both livestock and native grazers.
- Infestations cause increased runoff, sedimentation, and decreased water-holding capacity in soil.
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