Rhubarb

Rhubarb here is Chinese or Turkey rhubarb, a herbaceous perennial of the knotweed family, Polygonaceae, native to western China, northern Tibet and the Mongolian Plateau. It stands up to two metres tall, roughly twice the height of garden rhubarb, with large, jagged, hand-shaped leaves, tall sprays of tiny flowers and a thick, deep root that is brown outside and deep yellow within. That root, dahuang, has been used in traditional Chinese medicine for more than two thousand years; dried, it became one of the great goods of the Silk Road, and Europe used it for centuries before learning which plant it came from. Grieve describes it as a valued purgative whose after-effect is astringent, so that it can check diarrhoea, and in small doses a tonic for sluggish digestion. Kynes adds that China and medieval Europe both thought it a cure for plague, and that French and German alchemists called it by the secret name zipar. In magic Cunningham gives it to Venus and earth: a piece of root worn on a string at the neck guards against stomach pains, and rhubarb pie served to a partner keeps them faithful. Kynes adds air, Gemini, Jupiter and Saturn, and uses it for love, fidelity and abundance.