Stems erect, 5-10 dm, conspicuously hirsute on the angles with deflexed bristles to 2 mm; petioles to 1 cm, or none; lvs narrowly oblong or lanceolate, 4-12 × 1-4 cm, acuminate, serrate, usually distinctly hairy above; bracts long-ciliate and denticulate; cal-tube hirsute, rarely also minutely hairy, 3.3-4.7 mm, the lobes narrowly lanceolate to almost linear, at least three-fourths as long, hirsute or ciliate. Wet soil; Mass. and Vt. to Ont. and Man., s. to Md., Ky., and Ark. July, Aug. (S. tenuifolia var. h.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.