Lvs linear, 1-nerved, to 5 mm wide; otherwise much like no. 1 [Trichostema dichotomum L.], but apparently sharply distinct; 2n=38. Chiefly in the coastal states from Conn. to Fla. and Tex., and irregularly inland to O. and Tenn. July-Oct. (T. dichotomum var. lineare)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.