Northern Prairie Wildlife Research Center
Most North Dakota records for buffalo bur, also called "Kansas thistle", are from south or west of the Missouri River, but the plant has been collected in at least eleven counties east of the River. Buffalo bur originally inhabited the dry prairies and plains, but, since the advent of European man, it has spread to many areas of the United States and Mexico in fields, feedlots, and roadsides at elevations up to 6,000 feet.
Buffalo bur is a taprooted annual (reproduces each year by seeds) bearing long, yellow spines on stems, leaves, and flower heads. Plants collected in North Dakota are usually less than a foot tall. The oblong leaves are 2-3 inches long with deep rounded lobes. Flowers are bright yellow and about an inch wide. Berries up to 3/8 inch in diameter are totally enclosed by the dried flower parts and are filled with dark, pitted seeds.
Look for buffalo bur from May to October in dry, exposed soils in heavily grazed prairies and along roadsides. The berries and roots are possibly poisonous to swine.
Buffalo bur is a member of the potato or nightshade family (Solanaceae). The family has about 3,000 species worldwide; most are found in tropical America. The family includes some very valuable food plants including the tomatoes, bell peppers, and ground cherries as well as harmful or poisonous plants including tobacco, jimsonweed, henbane, and belladonna. The genus Solanum contains about 2,000 species. Solanum is an ancient Latin name for an unknown plant. Rostratum means "beaked" in reference to a characteristic of the pollen-bearing organs, the anthers. Buffalo bur was first described for science in 1813 by Michael Felix Dunal (1789-1856), professor of botany at the University of Montpellier, France.