Origin:
Native to western North America, and found in every state from Minnesota and Texas west to the Pacific coast, with isolated populations in a few eastern seaboard states.
Biology:
A perennial bushy warm season plant that reproduces from seeds and from the roots. The foliage, in particular, contains toxic substances that can cause serious problems in livestock, including loss of vigor and aborted fetuses. In cooler climates the above ground stems and leaves die, with new growth occurring from the crown and roots each year.
Identification:
Stems are narrow, stiff, and numerous, and plants generally grows no more than 2 feet tall. Leaves are alternate along the entire length of the stem, and are linear and up to about 1.5 inches long. The flower heads occur in small clusters at the tops of the stems, with yellow disc and ray flowers.
Characteristicts Important to Control:
A common plant found along roadsides and in natural areas, but needing removal in grazing areas. Physical removal may be effective and can eliminate seed production, but a systemic herbicide capable of killing the roots will be needed to eliminate the plants.