This distinctive species (with clasping leaves) is known mostly on the Coastal Plain and in the Great Lakes region, but there are occasional records further inland, as on the Cumberland Plateau in Tenn. (Ch). There are reports from Ky. (BT, J, M), including colls. from ADAI (for Field) and CLIN (for EKY). However, presence remains dubious pending location and examination of colls. The closely related T. fraseri (Spach) Gleason, with smaller flowers, is more northern but does occur in southern W.Va. (K, W).