The plant abounds in Yemen and Hadramaut in Southern Arabia; it is also found on the Somali coast, in Sind and the Punjab. In some parts of India it is now cultivated for medicinal use.
The uncultivated plant of Arabia supplies the so-called Bombay Senna of commerce, the true Senna Mekki of the East. The cultivated and more luxuriant plant, raised originally from Arabian seeds, furnishes the Tinnevelly Senna of the drug market.
History—According to the elaborate researches of Carl Martius,[838] a knowledge of senna cannot be traced back earlier than the time of the Elder Serapion, who flourished in the 9th or 1Oth century; and it is in fact to the Arabian physicians that the introduction of the drug to Western Europe is due. Isaac Judæus,[839] who wrote probably about a.d. 850-900 and who was a native of Egypt, mentions senna, the best kind of which he says is that brought from Mecca.
Senna (as Ssinen or Ssenen) is enumerated among the commodities liable to duty at Acre in Palestine at the close of the 12th century.[840] In France in 1542, a pound of senna was valued in an official tariff[841] at 15 sols, the same price as pepper or ginger.
The Arabian and the mediæval physicians of Europe used both the pods and leaves, preferring however the former. The pods (Folliculi Sennæ) are still employed in some countries.
Cassia obovata Coll.[842] was the species first known to botanists, and it was even cultivated in Italy for medicinal use during the first half of the 16th century. Hence the term Italian Senna used by Gerarde and others. In the records of the “Cinque savii alla mercanzia” at Venice we found an order bearing date 1526 to the effect that Senna leaves of Tuscany were inadmissible; the same was applied in 1676 to the drug from Tripoli in Barbaria, that from Cairo being exclusively permitted.
Production—According to Nectoux,[843] whose observations relate to Nubia at the close of the last century, the peasants make two senna harvests annually, the first and more abundant being at the termination of the rains,—that is in September; while the other, which in dry seasons is almost nil, takes place in April.
The gathering consists in simply cutting down the shrubs, and exposing them on the rocks to the burning sun till completely dry. The drug is then packed in bags made of palm leaves holding about a quintal each, and conveyed by camels to Es-souan and Darao, whence it is transported by water to Cairo. By many travellers it is stated that Senna jebeli, i.e. mountain senna (C. acutifolia), finds its way to the ports of Massowhah and Suakin, and thence to Cairo and Alexandria.
Cassia obovata, which is called by the Arabs Senna baladi, i.e. indigenous or wild senna, grows in the fields of durra (Sorghum) at Karnak and Luxor, and in the time of Nectoux was held in such small esteem that it fetched but a quarter the price of the Senna jebeli brought by the caravans of Nubia and the Bisharrin Arabs. It is not now collected.
Description—Three kinds of senna are distinguished in English commerce:—