Bistorta (L.) Scop. is a genus of perennial herbaceous plants in the family Polygonaceae (buckwheat family), comprising approximately 44 accepted species as of 2025. The genus sits within the subfamily Polygonoideae, tribe Persicarieae, and was formally established by Giovanni Antonio Scopoli in 1754, following Linnaeus's original grouping two years earlier. Molecular phylogenetic analysis supports Bistorta as a distinct clade within Polygonoideae.
Plants in the genus are characterized by fibrous, often contorted rhizomes, erect and unbranched stems, and leaves that are generally longer than wide — mostly basal with a few alternately arranged stem leaves. The inflorescences are dense, spike-like clusters of small bisexual flowers with five white to purple-pink tepals (rarely red) and 5–8 stamens. Fruits are unwinged, three-angled achenes in shades of brown. The monoploid chromosome number is x = 11 or 12.
The genus has a broad native range across the Northern Hemisphere, from Mexico in North America to Thailand in Asia, with centers of diversity in temperate and alpine zones. Species occupy a variety of habitats, but many favor moist or wet conditions such as streambanks, wet meadows, and subalpine zones. Well-known members include Bistorta officinalis (common bistort), B. vivipara (alpine bistort), B. amplexicaulis (red bistort), and B. bistortoides (American bistort).
Etymology
The genus name Bistorta derives from the Latin words meaning "twice-twisted" (bis = twice, torta = twisted), a reference to the contorted, S-shaped or doubly bent rhizome of the type species, Bistorta officinalis. The name reflects a common practice in pre-Linnaean botanical nomenclature of naming plants after a distinctive morphological feature.
Distribution
Bistorta has a wide native distribution across the Northern Hemisphere, ranging from Mexico in North America eastward through Europe and across temperate and montane Asia as far as Thailand. The genus is notably diverse in mountainous regions of central Asia. Bistorta bistortoides occurs in western North America from Canada to California, typically at montane to subalpine elevations above 2,500 meters in moist meadows and swamps.
Taxonomy
Bistorta was first circumscribed by Carl Linnaeus in 1753 and formally raised to genus rank by Giovanni Antonio Scopoli in his Methodus Plantarum of 1754, where the accepted citation Bistorta (L.) Scop. originates. The synonym Colubrina Montandon is occasionally encountered in older literature. Molecular phylogenetic work confirms Bistorta as a well-supported clade within the subfamily Polygonoideae, tribe Persicarieae, of the family Polygonaceae. GBIF recognizes the accepted name Bistorta (L.) Scop. (key 8148051) with descendant species recorded, while Plants of the World Online accepted 44 species and one natural hybrid (Bistorta × rhaetica) as of November 2025. The genus was long treated as part of the broader genus Polygonum, which accounts for the synonym Polygonum sect. Bistorta still encountered in historical texts.
Ecology
Many bistorts are plants of cool, moist to wet habitats — streambanks, wet meadows, subalpine and alpine zones. Bistorta bistortoides is documented in montane–subalpine moist meadows where it stabilizes wet meadow soils and provides early-season pollen and nectar resources for pollinators. Plants are browsed lightly by deer and elk in spring. Species in the genus are generally tolerant of cold temperatures and waterlogging but sensitive to heat and drought.
Cultivation
Bistorts generally require consistently moist, cool soils and perform best where moisture is not limiting. They tolerate cold and temporary waterlogging. At warmer sites, light shade is preferred; in cool climates, full sun is suitable. Plants are heat-intolerant and drought-sensitive — prolonged dry conditions lead to leaf degradation. Several species, including B. officinalis and B. amplexicaulis, are grown as garden ornamentals for their showy poker-like flower spikes.
Propagation
Propagation is straightforward by two methods. Seeds germinate freely when sown in cold frames in spring. Division of clumps in spring or autumn is described as very easy and is the most common method for named cultivars. Division is the preferred method for propagating selected garden forms while maintaining true-to-type characteristics.
Cultural Uses
Bistorta bistortoides leaves are edible raw or cooked, described as mild, slightly mucilaginous, and pleasantly acid. Seeds are edible but small and labor-intensive to collect; they can be toasted and used as a thickener. Roots are extremely bitter due to high tannin content and require extensive boiling with multiple water changes before consumption. Medicinally, the astringent root has been used as a poultice for sores and boils. Caution is warranted for individuals with rheumatism, arthritis, gout, kidney stones, or hyperacidity due to oxalic acid and tannin content.
