Trailing stems to 6 dm, the erect or ascending flowering stems 1-2 dm; lvs long-petioled, broadly ovate, 3-6 cm, obtuse, shallowly crenate, cordate at base; spikes few- fld, 3-5 cm, the elliptic bracts little surpassing the cal; cal-tube 1 cm, the upper lobes 5-6 mm, the lower two 1 mm shorter; cor ascending, 2.5-3 cm. Rich mt. woods; sw. Pa. and s. O. to Tenn. and N.C.; rep. from Ill. May-July.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.