Senna

Senna, the leaflets of various species of the leguminous genus Cassia, containing a nanseous volatile oil and a purgative principle known as cathartic acid. The plants vary in size, but their leaves are pinnate, and the leaflets are distinguishable from adulterants by being slightly oblique at their bases. C. acutifolia and C. angustifolia are shrubs, the one, known as Alexandrian or Nubian Senna, native of tropical Africa from Timbuctoo to Nubia; the other, known as Bombay or Tinnevelly Senna, native of Somaliland, Arabia, and the Punjaub. C. marilandica is the source of American Senna. In addition to a cathartic acid, the leaves contain oxalic, tartaric, and malic acids. The principal preparations of senna are the syrup, tincture, infusion, confection, and the compound senna mixture, or "black draught." The dose of the last named is 1 to 1-1/2 fluid ounces. The action of senna is to stimulate the muscular coat of the intestine, and black draught is one of the most commonly employed among purgative preparations.