Weed It & Reap: Have You Seen This Weed?
Text and illustration by Jessica Sprajcar
Last Seen: This native of Eurasia is now spreading through farm fields and along roadsides in all states except those in the southeast and south-central parts of the U.S.
Aliases: Centaurea stoebe, Centaurea biebersteinii, Centaurea maculosa
Description: A rosette of leaves forms close to the ground during its first year. In subsequent years, this two to three feet tall plant forms thistle-like pink to purplish flowers that bloom from July through early fall.
If yon spot this plant, don't take a nap... A thick root structure and abundant seeds that can remain viable in the soil for up to seven years make knapweed a formidable plant to deal with. Populations can spread quickly, so don't let it grow out of control. To learn how to combat this invader, go to http://www.nps.gov/plants/alien/fact/cest1.htm.