The Collaborative International Dictionary
Bistort \Bis"tort\, n. [L. bis + tortus, p. p. of torquere to twist: cf. F. bistorte.] (Bot.) An herbaceous plant of the genus Polygonum, section Bistorta; snakeweed; adderwort. Its root is used in medicine as an astringent.
Wikipedia
Bistorta is a genus of flowering plants in the Polygonaceae family with only one accepted species, Bistorta sherei H. Ohba & Akiyama (2002). It has been supported as a separate clade by molecular phylogenetic analysis. A number of species that were once assigned to Bistorta are now either treated as synonyms of species in the genus Persicaria, or currently remain unresolved.
Usage examples of "bistorta".
Miss Rohde (Old English Herbals) says: 'It is interesting to find that Turner identifies the Herba Britannica of Dioscorides and Pliny (famed for having cured the soldiers of Julius Caesar of scurvy in the Rhine country) with Polygonum bistorta, which he observed plentifully in Friesland, the scene of Pliny's observations.