Plants with a short, stout rhizome or branched caudex; stem 2-10 dm, pubescent with short, spreading, often coarse hairs, or merely scabrous; lvs thick and firm, scabrous-hirsute above, more loosely and softly hairy beneath, entire or nearly so, petiolate, the basal and lower cauline ovate or lanceolate, deeply cordate, 4-9 נ2-5.5 cm, the middle and upper gradually or abruptly reduced; infl open, paniculiform, with numerous narrow bracts, the bracteate peduncles often very long, invol 6-10 mm, short-hairy (subglabrous), the elongate, narrow, well imbricate bracts with reflexed green tip; rays 20-45, bright blue, 7-15 mm; achenes glabrous; 2n=16, ?18. Dry woods, usually associated with limestone; Ozark region from s. Ill. to e. Kans., Okla., and Ark.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.