CASSIA (from the Greek ucurola), a genus of plants belonging to the natural order Leguminosce. It consists of a large number of species, chiefly inhabiting the tropical or temperate parts of the world, and including among them the plants that produce the Senna leaves so commonly employed as a purgative. The genus Cassia belongs to the suborder Ccescdpiniece of Legurainove, and is character ised by De Candolle as follows :—Calyx consisting of five sepals which scarcely adhere at their base, but are more or less irregular. Petals five, unequal in size ; stamens tan, distinct from each other ; the three lowest being the longest, the four intermediate ones shorter and straight, and the three uppermost deformed; such of the anthers as are perfect open at the point ; ovary stalked, usually curved ; legume variable in form ; the species consist of trees, shrubs, or mere herbs ; the leaves are simply and abruptly pinnhted, and usually bear glands on their stalks ; the leaflets are opposite each other. Between 200 and 300 species are described by botanists.
C. acutifolia, a small under-shrub, with ovate lanceolate sharp pointed leaflets, yellow flowers in terminal erect racemes, and compressed velvety legumes an inch long and half an inch broad. It is found wild in Egypt, Sennaar, and Abyssinia, and forms an important article in the commerce of those countries. It is chiefly sent to Alexandria for shipment, whence it has gained the name of Alexandrian Senna among the drug-merchants. It is considered the most valuable of all the sennas.
a °Lopata, Aleppo Senna, has obovato very-blunt leaflets, and curved pods, with a very slight covering of down. The flowers are pale yellow. It is common in the same countries as the last, and mixed with it in commerce ; it however chiefly constitutes the Aleppo Senna.
C. lanceolate. Leaflets very narrow and acute ; pods piano compressed, atraightish, a little tumid in the middle. Found wild in Arabia, whence it is exported under the name of Senna of Mecca.
It is a good deal cultivated in India, on which account, and from its being usually shipped for Europe from Indian ports, it has acquired the name of East Indian Senna in the market. As a species it appears to differ very little if at all from C. acutifolia.
Of the different species of Cassia mentioned above only the leaves are used in medicine. C. Fistula and other species are now referred to Cathartocarpus. [CATIIANTOCARP08.] The leaflets of several different species of Cassia belonging to the section Senna constitute the various kinds of Senna called Senna leaves. In addition to the leaflets, the leaf-stalks and pods are frequently present, especially in the Alexandrian Senna, which contains also the leaves and pods of Tephrosia Apollinea, and the leaves, but rarely the follicles, of Cynanchum A rghel, Dane (C. olecefolium, Nectoux), a plant belonging to the natural order A pocynacece, which possesses deleterious properties. The leaves of this last-named plant constitute two parts in ten of the Senna of Alexandria. The, Tripoli Senna is free from it, as is likewise the Trinivelly Senna, which is now the best and cheapest in the markets of this country, and should always be preferred, as much of the griping tendency of common Senna is due to the presence of the Argel leaves. The Senna Leaves met with in the continental markets or shops are frequently adulterated with the leaves and berries of the Coriaria myrtifolia, a very poisonous plant.
When free from adulterations, Senna furnishes a most valuable purgative medicine; but when impure, its action is accompanied with nausea, griping, and other unpleasant symptoms. It is desirable therefore to free it from impurities before administering it or sub jecting it to the action of water to form an infusion. [SENRA, in ARTS AND Sc. Div.]