(Senecio jacobea L.)
Photo from Weeds of the West, revised edition
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.
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.