Of late, I have had cause to make several journeys from Shalesmoor into Neepsend, each time crossing the river Don. On the banks of this river I have observed large stands of donkey rhubarb – otherwise known as Japanese knotweed.
Having learned of the medicinal benefits of this strange and pungent plant, I have now begun to gather a small amount each time that I pass by – to consume with my evening meal as an aid to digestion.
Japanese knotweed Fallopia japonica is a large, herbaceous perennial plant, native to eastern Asia in Japan, China and Korea. In North America and Europe the species is very successful and has been classified as an invasive species in several countries.
A member of the family Polygonaceae, Japanese knotweed has hollow stems with distinct raised nodes that give it the appearance of bamboo, though it is not closely related. While stems may reach a maximum height of 3–4 m during each growing season, it is typical to see much smaller plants in places where they sprout through cracks in the pavement or are repeatedly cut down. The leaves are broad oval with a truncated base, 7–14 cm long and 5–12 cm broad, with an entire margin. The flowers are small, cream or white, produced in erect racemes 6–15 cm long in late summer and early autumn.
Other English names for Japanese knotweed include: Hancock’s curse, elephant ears, pea shooters, donkey rhubarb (although it is not a rhubarb), sally rhubarb, fleeceflower, Himalayan fleece vine, monkeyweed, Japanese bamboo (although it is not a bamboo), American bamboo, and Mexican bamboo. There are also regional names, and it is sometimes confused with sorrel.
In Japanese, the name is itadori 虎杖, イタドリ
Japanese knotweed is a concentrated source of emodin, used as a nutritional supplement to regulate bowel motility.The roots of Japanese knotweed are used in traditional Chinese and Japanese herbal medicines as a natural laxative. Some caution should be exercised when consuming this plant because, similarly to rhubarb, it contains oxalic acid; which may aggravate conditions such as rheumatism, arthritis, gout, kidney stones or hyperacidity.
Paul Evans, 13 December 2011