Department Header For Noxious Weed Division
Yellowstone County, Montana
Noxious Weed
Weed Information Contact Department

Tansy Ragwort
(Senecio jacobea L.)


Tansy Ragwort

Photo from Weeds of the West, revised edition

Tansy Ragwort Toxic

Tansy Ragwort Rosetta

Tansy Ragwort Stem

Tansy Ragwort Leaf

Tansy Ragwort Bloom

Tansy Ragwort Seed

Toxic: Toxic. All livestock, most especially cattle and horses.

Growth Habit: Biennial or short-lived perennial, 1 to 6 feet tall, solitary or several.

Leaves: leaves are 2 to 8 inches long, alternate and equally distributed, mostly 2 to 3 times pinnately lobed, the terminal lobe generally larger than the lateral ones.

Stem: 1 to 6 feet tall, solitary or several.

Flower: Flowering heads are numerous, both ray and disk flowers are yellow; ray flowers are 10 to 13 in number and ¼ to ½ inch long.

Roots: Taproot

Seeds: minutely pubescent

Reproduction: By Seed

Habitat: Range and Pasturelands

Biological Control: Cinnabar Moth, Ragwort Seed Fly, Tansy Ragwort Flea Beetle

Herbicide: 2,4-D, or 2,4-D + dicamba, or 2,4-D + trichlopyr

Caution: Tansy Ragwort is toxic to cattle, horses, sheep, humans and pets.

Video Supplied By Montana Weed Control Association