Fallopia, commonly called bindweed or knotweed, is a genus of flowering herbs and vines in the buckwheat family, Polygonaceae. There are 12 to 15 species, native throughout the northern hemisphere. While some species of Fallopia are valued and cultivated for their medicinal properties or their ornamental appearance, many are also considered invasive weeds, especially in areas in which they were introduced.
One Asian Fallopia species is F. baldschuanica, with common names including Chinese fleece vine, Russian vine, and silver lace vine. F. baldschuanica has been naturalized in areas of Europe and North America, where it has been introduced as an ornamental plant. F. baldschuanica has abundant white flowers that resemble lace and are sometimes tinged with pink or green. Like other Fallopia species, it grows quickly and easily and can become invasive.
Japanese knotweed, or F. japonica, is an herb native to eastern Asia. It is used to make honey in Asian countries and the United States, but it has also become invasive in North America and Europe. It is found in 39 of the United States and six Canadian provinces. Japanese knotwood also features edible stems and is a source of resveratrol, believed to treat cancer and prolong life. Chinese knotwood, or F. multiflora, is a vine native to parts of China.
Giant knotweed, or F. sachalinensis has a native range including northern Japan and eastern Russia. Like Japanese knotwood, it is rich in resveratrol and has edible shoots. It as also invasive outside of its native area. Two hybrids between F. japonica and F. sachalinensis have arisen in the wild: F. x conollyana or railway-yard knotweed, and F. x bohemica or Bohemian knotweed.
F. convolvulus, or black bindweed, has a large native range, spanning parts or Europe, Asia, and Africa. Black bindweed is a vine with pale green flowers that grows best in direct sun and dry soils. It was historically cultivated in Europe as a food crop, though the edible seeds are produced in quantities too small for the plant to be commercially valuable. F. convolvulus is largely considered an invasive weed, especially in North America, where it is an introduced species.
Fallopia species not only grow extremely quickly, but are dispersed over a wide area by floods. They tend to crowd out other plants, and are resistant to cutting and herbicides. The root system can also destroy roads and the foundations of buildings.
