WILD SENNA; a genus of the monogynia order, belonging to the decandria class of plants. There are 50 species, all of them natives of warm climates. The most remarkable is the fistula, or purging caffia of Alexandria. It is a native of Egypt and both Indies, where it rises to the height of 40 or 50 feet, with a large trunk, dividing into many branches, garnished with winged leaves, composed of five pair of spear-shaped lobes, which are smooth, having many transverse nerves from the midrib to the border. The flowers are produced in long spikes at the end of the branches, each standing upon a pretty long foot-stalk; these are composed, like the former, of five yellow concave petals, which are succeeded by cylindrical pods from one to two feet long, with a dark brown woody shell, having a longitudinal seam on one side, divided into many cells by transverse partitions, each containing one or two oval, smooth, compressed seeds, lodged in a blackish pulp, which is used in medicine. Among the species of caffia, Linnaeus mentions the common Senna of the shops; which see. With regard to the culture of all the species, they are propagated by seeds which must be sown upon a hot-bed, and the plants treated in the same manner with other tender exotics. The fistula must have very little water in winter; for the plants grow naturally in dry sandy ground, and moisture is a great enemy to them.

The pulp of the caffia fistula is a gentle laxative, and frequently given in colitive habits, in the dose of some drams. Geoffroy says it does excellent service in the painful tension of the belly which sometimes follows the imprudent use of antimonials; and that it may be advantageously acuated by the more acid purgatives, purgatives, or antimonial emetics, or employed to abate their force. Valliflier relates, that the purgative virtue of this medicine is remarkably promoted by manna; that a mixture of four drams of cassia, and two of manna, purges as much as 12 drams of cassia alone, or 32 of manna alone. Sennertus observes, that the urine is apt to be turned of a green colour, by the use of cassia; and sometimes, where a large quantity has been taken, blackish. See Materia Medica, no 223.

Cassia-Lignea. See Cinnamomum.