Rheum palmatum/R. officinale
There has been some confusion regarding the geographical origin of Rhubarb since it is variously known as Turkey Rhubarb, Chinese Rhubarb or Russian Rhubarb. It appears that the medicinal Rhubarb is in fact one and the same species, but the confusion arose because of different trade routes by which it entered Europe. Originally the medicinal Rhubarb comes from China and Tibet. This species has been known and used in Europe since at least the 18th century. It is related to our garden Rhubarb and, as for that species, the leaves are highly toxic. However, the Chinese Rhubarb (also known as Turkey Rhubarb) is a distinct species, which grows extremely fast and very large - several inches a day, according to Mrs Grieves: '...In one day it was observed to grow 3 inches and over 4 inches in one night.' It is the root which is used medicinally. It is hardly surprising that the Chinese valued it so highly - as apparently, did the British, who responded with canon fire to a Chinese threat to stop Rhubarb export. This is said to have been the beginning of the so called Opium war. Perhaps it was due to the Opium that the Chinese and British were so desperate for this magic root - Opium is among the most effective substances to stop diarrhoea - in other words, people who are habituated to Opium (as most of the 18th century society was - Opium was THE most commonly prescribed medicinal substance in the Western world) were likely also almost constantly constipated - hence the need for a reliable, yet gentle laxative like Rhubarb. (English Rhubarb is ordinary garden Rhubarb, whose medicinal action is not as pronounced.)
Medicinal Rhubarb is one of the best, most reliable and gentle laxatives available in the herbal material medica. In fact, it has long been official in the British pharmacopoeia. Small doses act slightly astringent, while large doses are laxative. It acts by stimulating the peristaltic movement and thus has a toning effect on the whole digestive system. In the past it was a favourite remedy for children as it was considered mild, safe and reliable. Mrs Grieves mentions its use for treating bacillary dysentery. In ancient China it was also used for the plague and to treat certain venereal diseases. Some laboratory studies have shown it to have anti-tumour activity in mice. However, this has not been studied further in any human trials, but, it is interesting to note that Rhubarb is one of the original herbs included in the Essiac formula, which is believed to have anti-tumour effects in humans.
Following our ancestor's traditions, an amulet of Rhubarb root can be used as a charm to protect against jaundice. During the time of the great plague Rhubarb was used for protection against the black death. In modern use it may be adapted as a protective charm against grave infectious diseases. It is purifying and cleansing.