Diffuse Knapweed
(Centaurea diffusa)

Photo from Weeds of the West, revised edition

Growth Habit: diffusely branched annual or short-lived perennial, 1 to 2 feet tall.

Leaves: Leaves are pinnately divided.

Stem: Stems are rough to the touch. 1 to 2 feet tall.

Flower: Flowers are white to rose or sometimes purplish; margins of involucral bracts are divided like the teeth of a comb, and bracts are tipped with a definite slender spine. Achenes are brown or grayish; pappus is lacking.

Roots: Elongated taproot

Seeds: Oblong, dark brown or grey with longitudinal lines.

Reproduction: By seed

Habitat: Diffuse Knapweed can be found in pastures, rangeland, roadsides, waste areas, as a highly competitive plant.

Biological Controls:

Herbicides: Tordon, Tordon + 2,4-D, Curtail + 2,4-D, dicamba + 2,4-D, Milestone