Rhizomatous perennial; stems weak but mostly erect, 2-8 dm, retrorsely strigose-puberulent especially along the angles, or less often glabrous or glandular; lvs barely or scarcely petiolate, the blade lanceolate to narrowly ovate-oblong, pinnately veined, mostly blunt-toothed, 2-6 cm נ6-20 mm, truncate-subcordate at base, glabrous above, usually puberulent beneath; fls solitary in the axils of slightly reduced lvs; cal 3.5-4.5 mm; cor blue marked with white, 1.2-2 cm; 2n=32. Wet soil; circumboreal, s. to Del., Ind., Mo., and Calif. June-Aug. (S. epilobiifolia)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
General: Perennial, 20-80 cm tall; stems somewhat weak but erect, simple or branched, strigose-puberulent, particularly on the angles, sometimes glabrous or glandular; rhizomes slender. Leaves: Cauline, opposite, simple, lanceolate to narrowly ovate- oblong, 2-6 cm long, 6-20 mm wide, glabrous above, puberulent to nearly glabrous and paler beneath, margins crenate-serrate to blunt-toothed, base truncate to sub- cordate; petioles 1-4 mm long. Flowers: Inflorescence an elongate raceme, usually with 2 flowers at each node; pedicels 2-3 mm long; bracts subtending the flowers minute, leaf-like, deciduous; calyx 5-7 mm long, enlarging some in fruit, puberulent on the veins, deeply bilabiate, the upper lip broad, abruptly pointed, the lower lip cleft about halfway to the base, the apices also abruptly pointed; corolla 8-12 mm long, blue, central lobe of the lower lip large, broadly rounded, lateral lobes much smaller; stamens 2; flowers July- October. Fruits: Nutlets 4, the surface variously marked. Ecology: Moist meadows, marshes, streambanks, other wetland habitats; 1800-2900 m (6000-9500 ft); Apache, Gila, and Yavapai counties; widely distributed throughout North America. Notes: na Editor: Springer et al. 2008