Nabalus crepidineus

Nabalus crepidineus (formerly Prenanthes crepidinea), commonly called the nodding rattlesnakeroot, is a species of plant in the Asteraceae family occurring in the northern central United States.

It is a perennial which grows in mesic environments and blooms in late summer and autumn. In 2010 it was reclassified from the genus Prenanthes to Nabalus