(Centaurea repens L.)
Sunflower family - Asteraceae
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.