The Mission of the Yellowstone County Weed Department is to assist the public, private, and other government agencies to manage and control existing noxious weed infestations as well as to prevent new invasive species from infesting Yellowstone County.

Common TeaselDipsacus fullonum L.

Photo from Weeds of the West, revised edition

Attribute	Information
Growth Habit	Biennial which grows to 6 feet in height.
Leaves	Leaves are conspicuously veined, with stiff prickles on the lower midrib. Stem leaves are lanceolate and are up to 10 inches in length.
Stem	The stem is striate-angled with several rows of downward turned prickles.
Flower	Flowers are purple, borne in dense heads, each flower subtended by spine-like bractlets.
Roots	Taproot
Seeds	Fruits are 4-angled, each with a single seed.
Reproduction	By Seed.
Habitat	Most common in moist sites along irrigation ditches, canals, and disturbed areas.
Biological Controls
Herbicides	Glyphosate, 2,4 - D amine