Plants (10-)20-70(-75) cm; rhizomes contorted. Stems 1-3. Leaves: ocrea brown, cylindric, 9-25(-32) mm, margins oblique, glabrous; petiole attached to sheath 10-35(-50) mm, usually wingless, rarely winged distally, (10-)30-70(-110) mm; blade elliptic to oblong-lanceolate or oblong-oblanceolate, (3.5-)5-22 × 0.8-4.8 cm, base tapered to rounded, rarely abruptly truncate or cuneate, often asymmetric, margins entire, sometimes wavy, apex usually acute to acuminate, rarely obtuse, abaxial face glabrous or pubescent with whitish or brownish hairs, glaucous, adaxial face glabrous, not glaucous; cauline leaves 2-6, petiolate proximally, sessile distally, gradually reduced distally, blade elliptic or lanceolate to linear-lanceolate. Inflorescences 1(-2), short-cylindric to ovoid, (10-)20-40(-50) × (8-)12-25 mm, bulblets absent; peduncle 1-10 cm. Pedicels ascending or spreading, 2-8(-11) mm. Flowers 1-2 per ocreate fascicle; perianth white or pale pink; tepals oblong, 4-5 mm, apex obtuse to acute; stamens exserted; anthers yellow, elliptic. Achenes yellowish brown or olive-brown, 3.2-4.2 × 1.3-2 mm, shiny, smooth. 2n = 24. Flowering Jul-Sep. Streambanks, moist or swampy meadows, alpine slopes; 1300-3800 m; Alta., B.C.; Ariz., Calif., Colo., Idaho, Mont., Nev., N.Mex., Oreg., Utah, Wash., Wyo. Infrequent specimens of Bistorta bistortoides have basal leaf blades that are lance-ovate and abruptly contracted at the bases, and petioles distinctly winged distally, similar to those of B. officinalis.

Roots of western bistort were used in soups and stews by the Blackfoot, boiled with meat by the Cherokee, and used in a poultice that was applied to sores and boils by the Miwok (D. E. Moerman 1998).

General: Perennial, 20-70 cm tall; stems 1-3, erect, simple, glabrous; rhizomes thick, contorted; roots fibrous. Leaves: Mostly basal (well developed), some cauline, alternate, elliptic, oblong, or oblanceolate, 5-22 cm long, 0.8-4.8 cm wide, glabrous above, glabrous to pubescent and glaucous below, margins entire, sometimes wavy; ocreas cylindric, 9-25 mm long, papery, brown; petiole mostly 3- 7 cm long, attached to sheath. Flowers: Inflorescence a dense, many-flowered raceme, appearing spike-like; sepals 5, the outer three 1-2 mm long, green with white membranous margin, the inner two 3 mm long, petaloid, white; petals 3, white with greenish center, the crest of the keel petal often purplish; flowers May- September. Fruits: Achene, 3-angled, 3-4 mm long, yellowish brown to olive- brown, smooth, shiny. Ecology: Moist mountain meadows, streambanks, alpine slopes; 1800- 3400 m (6000-11000 ft); Apache, Coconino, Graham, Greenlee, Navajo, and Yavapai counties; western Canada, western and southwestern U.S. Notes: na Editor: Springer et al. 2008