Coarse, taprooted, rough-hairy, 1-3 m; lvs alternate, deeply pinnatifid or bipinnatifid, the lower very large, to 5 dm, progressively reduced upwards, the uppermost entire and well under 1 dm; heads in a narrow, sometimes racemiform infl, large, the disk 2-3 cm wide; invol 2-4 cm, exceeding the disk, its bracts ovate, acuminate, squarrose, not much imbricate; rays (13-)17-25(-34), 2-5 cm; 2n=14. Prairies; O. to Minn. and S.D., s. to Ala. and Tex.; locally intr. e. along railroads to N.Y. July-Sept. The basal lvs tend to align themselves in a north-south direction.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
This species is a true prairie plant and in its distribution in Indiana it was restricted to the prairie areas. All of our prairie areas are under cultivation and it is found now only in moist prairie habitats along railroads and roadsides. The published records extend its range somewhat beyond that shown on the map. Beyond the area indicated by the map, it has been reported from the area of Delaware, Jay, Randolph, and Wayne Counties, and from Elkhart, Knox, and Noble Counties.