Squarrose KnapweedCentaurea virgata
BACKGROUND: Squarrose knapweed is a native plant of the eastern Mediterranean area. It is very competitive on rangelands. Knapweed releases a chemical substance reducing competing vegetation.
DESCRIPTION: This long-lived perennial grows 12 to 18 inches tall. The rosette and stems have deeply lobed leaves. Flowers are rose to pink. It is often confused with diffuse knapweed, but differs in that the toothed flower bracts are curved outward, and are not laterally toothed. Bloom occurs in early to mid-summer.
CONTROL: Several biocontrol agents are available. Herbicides offer good to excellent control. Contact your local state or county weed specialist for specific updated information.