Botanical name: 

The purgative tuber known under the common name jalap, Exogonium purga, is a gift of Mexico, and by reason of its cathartic qualities naturally became a favorite in Europe in the days of heroic medication. The early Spanish voyagers learned of its qualities from the natives, and in the sixteenth century carried large quantities to Europe. Monardes (447), in 1565, mentions a cathartic under the name Mechoacan rhubarb, or root, which some believe to have been jalap, but this Flückiger (239) discredits, because Colon, an apothecary of Lyons, in 1619, states that jalap was then newly brought to France. Flückiger also accepts that both drugs were well known in 1610, although often confused. Owing to this confusion between the two bulbs, one was called black mechoacan, while the other was known as white jalap. Strangely enough, the exact botanical source of jalap remained a question until 1829, when Dr. Coxe, of Philadelphia, author of Coxe's American Dispensatory, identified the drug from living plants sent to him from Mexico, and published descriptions, with colored plates, in the American Journal of Medical Sciences, 1829. This celebrated cathartic, so much used by licensed physicians and in domestic medication, is to be credited to the natives of Central America, whose employment of the drug introduced it to European commercial adventurers who, as a matter of business, made it known to the professions of medicine and pharmacy.

The History of the Vegetable Drugs of the U.S.P., 1911, was written by John Uri Lloyd.