Russian Knapweed
(Centaurea repens L.)
Sunflower family - Asteraceae

Photo by Tom Whitson, Roy Reichenbach

Produced by Wyoming Weed & Pest Council in cooperation with Sandoz Crop Protection Corp.

Photos from Montana Weed Control Association

Toxicity: Toxic. Horses.

Growth Habit: Perennial herb, up to 3 ft. tall, erect, may be in dense clumps. Grayish color

Leaves: Alternate, simple, of several types: Upper leaves -- small, narrow, unbroken edge; Stem leaves -- intermediate in size, slight toothed margins; Basal leaves -- deeply notched.

Stem: Numerous branched, each ending with a single flower.

Flower: Single, terminal, lavender, thistle like, scaly seed head.

Roots: Dark brown to black and heavily scaled.

Seeds: Flattened, ivory colored, retained in cup shaped seed heads.

Reproduction: Seeds and creeping rootstocks.

Habitat: Grazing land, grain and other crops, waste places, roadsides, river banks, and irrigation ditches.

Biological Controls: Russian knapweed gall nemotode (Subanguina picridis).

Herbicides: Tordon, Curtail, Transline, Telar, Milestone.