This plant is extremely rare in Indiana. The only recent specimens are from the low dunes near Lake Michigan in Lake and Porter Counties. It formerly was frequent on the low dunes at Pine, now the north end of Clark Street in Gary, but in 1935 search was made for it and only a few plants were seen. It will soon be extinct at this station, and only a few plants have been seen in Porter County. In the Wabash College herbarium are two sheets collected by Dr. A. Clapp Aug. 6, 1835, in the "barrens" (in Floyd or Harrison Counties).
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.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.