| Reynoutria multiflora | |
|---|---|
 | |
| Chinese knotweed | |
Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Order: | Caryophyllales |
| Family: | Polygonaceae |
| Genus: | Reynoutria |
| Species: | R. multiflora |
| Binomial name | |
| Reynoutria multiflora | |
| Synonyms[1] | |
| |
Reynoutria multiflora (syn.Fallopia multiflora andPolygonum multiflorum) is a species offlowering plant in the buckwheat familyPolygonaceae[1] native to central and southernChina.[2][3] It is known by the English common namestuber fleeceflower[4] andChinese (climbing) knotweed. It is known ashe shou wu (何首烏) in China and East Asia.[5] Another name for the species isfo-ti,[6][7][8] which is a misnomer.[9]
It can be difficult to prevent the spread of this vine and to remove it once established. The leaves are thin and fragile but the stems, although narrow in diameter, can be very strong.
Reynoutria multiflora is aherbaceousperennialvine growing to 2–4 m (6 ft 7 in – 13 ft 1 in) tall from a woodytuber. Theleaves are 3–7 cm (1.2–2.8 in) long and 2–5 cm (0.79–1.97 in) broad, broad arrowhead-shaped, with an entire margin. Theflowers are 6–7 mm (0.24–0.28 in) diameter, white or greenish-white, produced on short, densepanicles up to 10–20 cm (3.9–7.9 in) long in summer to mid-autumn. Thefruit is anachene 2.5–3 mm (0.098–0.118 in) long.[2]
In Chinese folklore, it is believed that the root of he shou wu (何首烏,Reynoutria multiflora) can, after a thousand years, transform into a human form, either as a child or an old person. It is also said thatZhang Guolao, one of theEight Immortals, achieved immortality by consuming the essence of he shou wu.[10]
Two types of stories often revolve around the essence of he shou wu. In one version, a monk or Taoist acquires a human-shaped he shou wu and instructs a disciple to cook it. The disciple, tempted, secretly tastes it, becomes immortal, and disappears. In the other version, the essence of he shou wu takes on human form and accompanies a woman. Finding his behavior suspicious, the woman sews a thread into him. The following day, she traces the thread and finds it attached to a he shou wu root, from which a human shape is growing.[10]
Reynoutria multiflora is listed in theChinese Pharmacopoeia and is one of the most popular perennialtraditional Chinese medicines. Caution must be taken, however, as overconsumption can lead totoxicity-induced hepatitis.[11]
More than 100 chemical compounds have been isolated fromReynoutria multiflora, and the major components have been determined to bestilbenes,quinones,flavonoids, and others.[citation needed] Its extract contains astilbeneglycoside.[12][13]
