Buchnera americana L.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Stem mostly simple, 4–9 dm, roughly short-hairy; lower lvs lanceolate, 5–10 cm, acuminate, coarsely few-toothed, very scabrous, the upper progressively smaller and narrower; spikes peduncled, elongating in fr to 1–2 dm; cal hairy, 6–9 mm, much surpassing the subulate bracts; cor deep purple, the tube 1–1.5 cm, the lobes 5–8 mm; fr 6–8 mm, barely surpassing the persistent cal; 2n=42. Sandy or gravelly soil of upland woods or prairies; N.Y. and s. Ont. to Mich., Ill., and se. Kans., s. to Ga. and Tex. July–Sept.