Stout, fibrous-rooted, glabrous perennial 1-3 m; stem conspicuously 6-8-angled and sulcate; lvs green on both sides, irregularly dentate and sometimes shallowly lobed, commonly ±ciliolate in the sinuses, palmately veined, the lower very large and long-petioled, to 8 dm wide, often reniform, the upper reduced and more flabellate or ovate; heads numerous in a short and broad, flat-topped infl, 5-fld, narrowly cylindric, the disk 3-7 mm wide as pressed; invol 7-12 mm, its principal bracts 5, sometimes with a few minute basal bracteoles; receptacle with a short conic projection in the center; 2n=50. Open woods; N.J. and Pa. to Minn. and Mo., s. to Ga. and Miss. June-Sept. (C. reniformis; Mesadenia r.; M. muehlenbergii)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.