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American bistort, smokeweed, western bistort

alpine bistort, serpent-grass, viviparous bistort

Habit Plants (10–)20–70(–75) cm; rhizomes contorted. Plants (2–)8–30(–45) cm; rhizomes sometimes contorted.




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.

ocrea brown, cylindric, 4–22(–27) mm, margins strongly oblique, glabrous;

petiole attached to sheath 6–20(–45) mm, unwinged distally, 5–110(–200) mm;

blade linear to lanceolate or oblong-ovate, 1–8(–10) × 0.5–1.7(–2.3) cm, base cuneate to rounded or cordate, often asymmetric, margins entire, usually revolute, not wavy, apex obtuse to acute, abaxial face pubescent with whitish or brownish hairs, glaucous, adaxial face glabrous, not glaucous;

cauline leaves 2–4, petiolate proximally, sessile distally, gradually reduced distally, blade linear-lanceolate to linear.


1(–2), short-cylindric to ovoid, (10–)20–40(–50) × (8–)12–25 mm, bulblets absent;

peduncle 1–10 cm.

1, narrowly elongate-cylindric, (15–)20–90 × 4–10 mm, usually bearing pink to brown or purple pyriform bulblets proximally and sterile flowers distally;

peduncle 1–5 cm.


ascending or spreading, 2–8(–11) mm.

ascending or spreading, (1–)2–5 mm.


1–2 per ocreate fascicle;

perianth white or pale pink;

tepals oblong, 4–5 mm, apex obtuse to acute;

stamens exserted;

anthers yellow, elliptic.

1–2 per ocreate fascicle;

perianth greenish proximally, usually white or pink distally, rarely red;

tepals obovate, 2.1–4 mm, apex obtuse to acute;

stamens included or exserted, some or all often poorly developed;

anthers reddish to purple.


yellowish brown or olive-brown, 3.2–4.2 × 1.3–2 mm, shiny, smooth.

rarely produced, dark brown, 2.2–3.3 × 0.9–1.5 mm, dull, granular.


= 24.

= 96, 120.

Bistorta bistortoides

Bistorta vivipara

Phenology Flowering Jul–Sep. Flowering Jun–Sep.
Habitat Streambanks, moist or swampy meadows, alpine slopes Moist to wet spruce or mixed woods along shorelines, moist subalpine woods and meadows, alpine meadows, heaths, nutrient-rich sites
Elevation 1300-3800 m (4300-12500 ft) 0-4000 m (0-13100 ft)
from FNA
[WildflowerSearch map]
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from FNA
AK; AZ; CO; ID; ME; MI; MN; MT; NH; NM; NV; OR; SD; UT; VT; WA; WY; AB; BC; LB; MB; NB; NT; NU; ON; QC; SK; YT; SPM; Greenland; Europe; Asia
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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).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Bistorta vivipara is highly variable morphologically and cytologically. Robust plants with large leaves, compact spikes, and persistent bulblets have been named subsp. macounii. Abortion of stamens, production of bulblets, and the rarity of fruits suggest that reproduction is largely asexual; fruits and seedlings are produced rarely (N. Söyrinki 1989). B. Jonsell and T. Karlsson (2000+, vol. 1) summarized chromosome numbers that include 2n = 66, ca. 77, ca. 80, 88, 99, ca. 100, 110, 120, and ca. 132.

A. E. Porsild and W. J. Cody (1980) reported that indigenous peoples of the circumpolar region eat the starchy, slightly astringent rootstocks raw or cooked, and preserve them in seal oil or by freezing. E. Hultén (1968) reported that the rootstocks taste like almonds.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 5, p. 596. FNA vol. 5, p. 595.
Parent taxa Polygonaceae > subfam. Polygonoideae > Bistorta Polygonaceae > subfam. Polygonoideae > Bistorta
Sibling taxa
B. officinalis, B. plumosa, B. vivipara
B. bistortoides, B. officinalis, B. plumosa
Synonyms Polygonum bistortoides, B. bistortoides var. oblongifolia, Persicaria bistortoides, Polygonum bistortoides var. linearifolium, Polygonum bistortoides var. oblongifolium Polygonum viviparum, B. vivipara subsp. macounii, Persicaria vivipara, Polygonum viviparum var. macounii
Name authority (Pursh) Small: Bull. Torrey Bot. Club 33: 57. (1906) (Linnaeus) Delarbre: Fl. Auvergne ed. 2, 2: 516. (1800)
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