RHUBARB is the root of various species of Rheum, Nat. Ord. Polygonaceae. The rhubarb of commerce is obtained through various sources, and appears to have been known to the ancients, although much obscurity invests the history of the Rha or Rheon of the ancient Greek writers, and the rhacoma of the Romans. These names are supposed to have been applied to the dried roots of Rheum rhaponticum of Linnaeus, which is a native of Thracia, and of the coasts of the Euxine and Caspian seas, and part of Siberia. The rhubarb root was first introduced into European pharmacy by the Arabians, and was highly valued by Avicenna. The finer kinds of rhubarb are received from Chinese Tartary and possibly from Tibet. It finds its way to Europe through Russia; and from the fact, that the best kind was formerly sold by the merchants of Anatoli or Anatolia, it was called Turkey rhubarb. This sort is now generally imported from Russia and Turkey. There is another sort, rather inferior, which is called Canton or East Indian rhubarb, imported from Canton or Singapore. Of late, much rhubarb root has been prepared in Europe, and is either used as a milder medicine or for the purpose of sophisticating the finer foreign sorts. The town of Banbury in Oxfordshire has long been famous for the cultivation and preparation of English rhubarb, which is the product of Rheum rhaponticum; no other species is found to be of any value medicinally. Within the last few years the petioles or leaf-stalks of the various species of rhubarb have become a most
important staple of our vegetable markets, in consequence of their agreeable subacidity and their succulence, which renders them very useful and wholesome in tarts and other forms of food. The chief species of rhubarb now known are:—Rheum palmatum (Linn.), supposed to yield the Turkey rhubarb root; it is also cultivated in this country as a culinary vegetable. R. undulatum (Linn.) is the source of the French rhubarb. R. compactum (Linn.) is also cultivated in France for its root, which is prepared to imitate the foreign drug. R. Emodi (Wallich) yields that kind of East Indian rhubarb known in trade as Himalayan; it is also a favourite garden species. R. rhaponticum (Linn.) is the commonest kind in cultivation in our gardens. Hundreds of tons of the leaf-stalks of this species are sent to our markets every week during the season, and form a cheap and refreshing food for all classes. The roots also are prepared as before stated. Ten or twelve other species are known, and some of them are probably as well adapted for the purposes of medicine or cookery as those above mentioned, but they have not been so well examined.
The quantity of rhubarb root imported in 1858 was 211,117 lb., the estimated value of which was L.39,300. This large quantity is entirely consumed in pharmacy, it being applied to no other use than as a mild aperient medicine. (T. C. A.)