Native to the Great Plains area of the United States, and now occurring commonly in the Midwest to the west coast.
An annual weed, propagating by seed. Seeds germinate in mid to late spring and the plant matures in late summer. Plants may be found in most soil conditions, including crops.
Young leaves and seed pods contain toxic alkaloids, and the extremely stout, sharp spines on the seed pods and stems can cause injury to livestock. Plants also serve as an alternate host for the Colorado Potato Beetle.
Mature plants grow only to around 2.5 feet tall, and are extensively branched on the upper length of the stem. Long, stout, yellowish spines occur along the length of the stems and on the seed pods.
Leaves are alternate on the stems, may be 6 inches long, but are divided into lobes that make it appear that there are from 5 to 7 leaves on each stalk. These lobes may then again have 5 to 7 shallow to deep lobes. Like the stems, the leaves are covered with hairs and sharp spines.
Flowers are large and yellow. There are 5 petals, and each petal may be over 1 inch across. The calyx below the petals is covered with spines, and it is this calyx which enlarges to form the spiny seed pod covering the seeds.
Characteristicts Important to Control:
An annual weed.