Bistorta is a genus of flowering plants in the family Polygonaceae. about 40 species are accepted. It has been supported as a separate clade by molecular phylogenetic analysis.[ Bistorta species are native throughout much of the Northern Hemisphere, as far south as Mexico in North America and Thailand in Asia.][
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Description
Species of Bistorta are Perennial plant . Their roots are fibrous, forming . They have erect, unbranched Plant stem. Their leaves are usually longer than wide, mostly basal, but with some arranged alternately on the stems. The are spikelike. The individual flowers have five white to purple-pink (rarely red) . The flowers are bisexual, although the 5–8 stamens are sometimes poorly developed. There are three styles. The fruits are in the form of , that are brown or dark brown, unwinged, and three-angled. The Ploidy of chromosomes, x, is 11 or 12.[
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Taxonomy
In 1753, Carl Linnaeus divided up his genus Polygonum into unranked groups, one of which was Bistorta. In 1754, Giovanni Antonio Scopoli elevated Bistorta to a genus.[
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Bistorta is placed in the subfamily Polygonoideae, tribe Persicarieae, along with the genera Koenigia and Persicaria. A 2015 molecular phylogenetic study suggested that the tribes in Polygonoideae were related as shown in the following cladogram.[
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Within the tribe Persicarieae, Bistorta is most closely related to Koenigia:[
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Species
, Plants of the World Online accepted the following 44 species and one natural hybrid.[
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Bistorta abukumensis 5.JPG| Bistorta abukumensis
Beautiful Deosi Flowers.jpg| Bistorta affinis
Bistorta amplexicaulis Polygonium amplexicaule HabitusInflorescences BotGardBln0906a.jpg| Bistorta amplexicaulis
Bistorta bistortoides, Western bistort, Yosemite.jpg| Bistorta bistortoides
Bistorta macrophylla Tawang.jpg| Bistorta macrophylla
Bistorta vivipara T57.jpg| Bistorta vivipara
