Madison County Noxious Weed
Authority
Nebraska Noxious Weeds
Spotted Knapweed
(Centaurea maculosa Lam
)
Life Span: Perennial
Origin: Eurasia
Reproduction: Seeds
Diffused Knapweed
(Centaurea diffusa Lam
)
Life Span: Biennial (or short-lived perennial)
Origin: Eurasia
Reproduction: Seeds
The reason these plants are considered noxious is:
1. They are very aggressive, infesting dry rangeland and
waste areas.
2. They are prolific seed producers.
3. They are highly competitive, even killing vegetation that
grows below them.
These two plants have not been on the noxious weed list for very long, only since 1992. Both plants are very difficult to
distinguish between each other in the rosette stage. Both plants behave and look almost alike, but they have different blossom
bracts (under the flower), and the Spotted is usually purple, while the Diffuse is usually white.
For a more detailed description of
Knapweeds, check out the
Nebraska Weed Control Association
Website.
Noxious Weeds Home
If you have questions or comments about this site please email them to:
Webmaster
Madison County Noxious Weeds
3203 South 12th Street
Norfolk, Nebraska
Phone: 402-370-3576
Fax: 402-370-4358
©2002 Madison County, Nebraska
This page was last updated on
12/04/07.
