Reynoutria multiflora (syn. Fallopia multiflora and Polygonum multiflorum) is a species of flowering plant in the buckwheat family Polygonaceae native to central and southern China. It is known by the English common names tuber fleeceflower and Chinese (climbing) knotweed. It is known as he shou wu in China and East Asia. Another name for the species is fo-ti, which is a misnomer. It can be difficult to prevent the spread of this vining plant and to remove it once established. The leaves are thin and fragile but the stems, although narrow in diameter, can be very strong.

Description

Reynoutria multiflora is a herbaceous perennial vine growing to 2–4 m tall from a woody tuber. The leaves are 3–7 cm long and 2–5 cm broad, broad arrowhead-shaped, with an entire margin. The flowers are 6–7 mm diameter, white or greenish-white, produced on short, dense panicles up to 10–20 cm long in summer to mid-autumn. The fruit is an achene 2.5–3 mm long.

In folk belief

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 that Zhang Guolao, one of the Eight Immortals, achieved immortality by consuming the essence of he shou wu. 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.

Traditional medicine

Reynoutria multiflora is listed in the Chinese Pharmacopoeia and is one of the most popular perennial traditional Chinese medicines. Caution must be taken, however, as overconsumption can lead to toxicity-induced hepatitis.

Chemistry

More than 100 chemical compounds have been isolated from Reynoutria multiflora, and the major components have been determined to be stilbenes, quinones, flavonoids, and others. Its extract contains a stilbene glycoside.