Bistorta

[2] Bistorta species are native throughout much of the Northern Hemisphere, as far south as Mexico in North America and Thailand in Asia.

The individual flowers have five white to purple-pink (rarely red) tepals.

[3] In 1753, Carl Linnaeus divided up his genus Polygonum into unranked groups, one of which was Bistorta.

[4] 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.