The leaves of Cassia marilandica, Linné.
COMMON NAMES:American senna, Wild senna.
Botanical Source.—Cassia marilandica is an American, perennial herb, growing from 4 to 6 feet high, with round, striated, smooth, or slightly hairy stems. The leaves are alternate, on long petioles, at the base of which is a large, ovate, shining green gland, terminating in a dark point at top, which is sometimes double; each petiole contains from 8 to 10 pairs of leaflets, which are oblong, smooth, entire, mucronate, somewhat hair at the edges, 1 or 2 inches long, and from 5 to 10 lines broad. The flowers are bright yellow, in axillary racemes, extending quite to the top of the stem; the peduncles are slightly furrowed, and marked with minute, blackish, glandular hairs; sepals 5, oval, obtuse, the lateral the 3 upper have short abortive anthers; to these succeed 2 ones longest. Petals 5, concave, and very obtuse. Stamens 10, pairs of deflexed, linear, brown anthers; the remaining lowermost 3 taper into a sort of beak, the middle one being shortest. The fruit is a legume, from 2 to 4 inches long, pendulous, linear, curved, swelling at the seeds, furnished with slight hairs; seeds many (L.). It is sometimes called wild senna.
History and Chemical Composition.—This plant is frequently met with in alluvial soils, and in stony situations, from New England to North Carolina, flowering from June to September, about which time the medicinal parts of the plant should be gathered. The leaves yield their properties to alcohol or water: they are nearly odorless, have a senna-like, mawkish taste, and in medicinal power are equal to foreign senna. Mr. Martin, of Philadelphia, found the leaves to contain albumen, mucilage, starch, chlorophyll, yellow coloring matter, volatile oil, fatty matter, resin, lignin, salts of potassium and calcium, and a principle, resembling cathartin (Amer. Jour. Pharm., Vol. I, p. 22). It is also thought to contain chrysophan and cathartic acid (Amer. Jour. Pharm., 1888, p. 231).
Action, Medical Uses, and Dosage.—An excellent cathartic, equal to the imported article, for which it may be substituted. But owing to the presence of argel leaves, much of the foreign senna has its activity increased; hence, in giving the American article, its dose must be somewhat increased. It may be given in powder or infusion, and should be combined with aromatics to prevent any proneness to griping. The dose in powder is from ½ to 2 ½ drachms. The infusion may be made by adding 1 ounce of the leaves, with 1 drachm of coriander seeds, to 1 pint of boiling water. Macerate for an hour in a covered vessel and strain; dose, 4 or 5 fluid ounces.
Related Species.—Cassia Chamaecrista, Linné. Prairie senna or Partridge pea, growing on the western prairies, is an excellent substitute for the above; it is likewise known as Dwarf cassia and Sensitive pea.