Origin:
Native to the Great Plains in the U.S., and found from Wisconsin and Illinois west to Idaho and Arizona.
Biology:
A perennial plant with an extensive creeping root system, with reproduction from seeds. Plants mature at anywhere from 4 to 18 inches in height, adapting to conditions where they are mowed frequently by producing lateral stems and a more spreading habit. New growth may appear from these roots. Flowers and seed production occur in early to mid summer.
Identification:
The rough leaves are up to 5 inches in length and deeply lobate with an alternating pattern and toothed margins. The underside of the leaf and the stems are covered with short white hairs. The flowers are very small and borne in small clusters along the elongated upper stems. The seed is a light brown bur with several long flat spines on its edges.
Characteristicts Important to Control:
Extensive horizontal roots can make control difficult, and if a herbicide is to be used plants should be allowed to produce adequate foliage first. A systemic herbicide is needed to kill the entire plant and roots, and a pre-emergent herbicide may be effective on the seeds.
