A large hardy perennial, to 2 m (6 fat), on a thick rhizome, with a basal clump of palmate lobed leaves. Spires of reddish-green flowers arise on long, hollow stems in summer.
History and traditions
Rhubarb has been an important medicinal herb in China for many centuries. It is mentioned in the Shen Nong Canon of Herbs, dating from 206 scan 23, though claims exist that it has been recorded in much earlier Chinese texts, dating from 2700 sc. Several species of rhubarb (there are 50 in the genus) were used, but R. palmatum is thought to be the main source of Chinese medicinal rhubarb. The plant was first grown in Europe in 1763. R. officinale, also medicinal and of Chinese origin, came to Europe, as a plant, in 1867. However, rhubarb in dried or powdered form had been known for centuries before that in the West. It was imported to ancient Greece, where they called it rha-barbarum because it was brought by traders from the barbaric regions beyond the river Rha (Volga). It reached Europe in the 13th century and was in demand as a purgative drug, which lacked the side effects of other more toxic products, remaining popular into the 20th century. Rhubarb powder was a major constituent of the 19th-century proprietary medicine, Gregory powder, named after the Scottish doctor who patented it. And in an article in The Lancet, 1921, it is cited as a certain, even “magical”, remedy for dysentery, when administered in small, strictly controlled amounts.
Related species
Edible garden rhubarb is from hybrids, developed during the 19th century, of R. rhabarbarum syn. R. rhaponticum, and there are now many cultivars. It is slightly laxative, but does not have medicinal properties.
Habitat/distribution
Native to China and northeast Asia, found on deep, moist soils at altitudes of 3,000—-4,000 m. Introduced elsewhere in temperate zones.
Growth
Requires rich, moist soil and a sunny situation. It is possible to propagate from seed, but division of roots in spring or autumn is the preferable method. Cultivars must be propagated by division.
Parts used
Rhizomes dried for use in decoctions, powders and medicinal preparations.
Uses
Medicinal
Used in very small doses for diarrhoea and gastric upsets, and in larger doses for chronic constipation. Also given for liver and gall bladder complaints.
