Rhizomes tuberous-thickened at the end; stems weak and soft, 1-3 dm; lvs thin, ovate or deltoid-ovate, 2-6 cm, usually more than half as wide, acute, sharply and coarsely undulate-dentate, broadly truncate to more commonly cordate at base; petioles thin and ±flat above, and with a conspicuous thin median wing beneath; racemes rarely with more than 15 fls, elongating to 1 dm in fr, the fls at anthesis all clustered at the still unelongated top; pedicels 2-6 mm, glabrous, spreading or slightly deflexed in fr; sep 1-2 mm, white or pinkish, glabrous; pet 1-2.5 mm, bilobed to about the middle or less; anthers 0.2-0.3 mm; disk nearly obsolete; stigma capitate or inconspicuously bilobed; fr 2-3 mm, unilocular and 1-seeded, not ribbed or furrowed; 2n=22. Moist or wet woods and mossy bogs; circumboreal, s. to N.Y., Ind., Io., and S.D., and in the mts. to N.C., Tenn., and N.M. June-Aug. Ours is var. alpina.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
General: Perennial, 10-40 cm tall; stems solitary, simple, slender, delicate; herbage glandular-puberulent in the inflorescence; plants rhizomatous. Leaves: Cauline, opposite, ovate to sub-orbicular, 2-7 cm long, 1.5-6 cm wide, the lowest ones smaller, thin, glabrous or with few short hairs along veins and minutely ciliate along the margins, margins entire or often irregularly toothed; petiole 2-3 cm long. Flowers: Inflorescence a raceme, terminal, elongate, showy, with numerous flowers; floral tube absent; sepals 7-16 mm long, pinkish purplish, puberulent; petals unequal, slightly asymmetric, 1-2 cm long, pink-purple, seldom white; style 1-2 cm long, surpassing the stamens, stigma deeply 4-cleft; flowers July-September. Fruits: Indehiscent capsule, 1.5-2.5 mm long, club-shaped, obovoid, or top-shaped, beset with hook-shaped hairs; seed 1. Ecology: Thickets, ravines, canyons, montane regions, coniferous forests, often in shaded habitats and moist soils; 1400- 2700 m (4500-9000 ft); Apache, Coconino, Graham, and Navajo counties; Canada, northeastern, north-central, and western U.S. Notes: na Editor: Springer et al. 2008