Botanical name: 

Senna leaves are from two species of cassia, one of which is native to Nubia and other sections of Africa, while the other abounds in Yemen and Southern Arabia as well as in some parts of India, where it is cultivated for medicinal use. The cultivated plant, originally the product of Arabian seed, furnishes the leaves known in commerce as Tinnevelly senna. The drug was introduced into Western Europe by the Arabians, and in this connection it may be stated that, notwithstanding its present abundance in some parts of Africa, according to Isaac Judaeus (336a), a native of Egypt, who lived about 850-900 A. D., senna was brought from Mecca to Egypt. In early Arabian medicine the pods of the senna were preferred to the leaves. Its price in France, 1542, was about that of pepper or ginger. This writer found senna in the Orient, carried in shops selling foods and provisions, as well as in the Oriental bazaars, it being everywhere a familiar domestic cathartic. Its native use introduced the drug to medicine and antedates historical record.

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