This occurs mostly in the Great Plains, and in eastern states it is only a rare waif. L. ludoviciana is similar to hirsuta (Cr), but differs in its more prickly-toothed leaves, and its larger heads, with 20-56 flowers (versus 13-25). It was reported from Ky. by FNA 19, BA and Mohlenbrock et al. (1966). There is a verified coll. from CARL (O'Dell & Windler #990 at SIU), but an initially supposed coll. from CALL (MUR) has been redetermined as canadensis.