Dorstenia contrayerva. Contrayerva.
Nat. Ord. — Urticaceae. Sex. Syst. — Tetrandria Monogynia.
Description. — This is a caulescent plant, with a perennial, fusiform, rough, branching root or rhizoma; the stem is covered with spreading, green, scaly stipules. The leaves are about four inches in length, palmate, and placed upon long radical petioles, which are winged toward the leaves ; the lobes are lanceolate, acuminate, coarsely serrate and gashed, occasionally almost pinnatifid. The scapes or flower-stems are radical, several inches long, and support quadrangular, and waved or plaited receptacles, which contain male and female flowers, the former having two stamens, the latter a single style. The capsule when matured, throws out the seeds with considerable force.
History. — This plant grows in Mexico, the West Indies, and Peru. The root is the officinal part ; as found in the shops, it is oblong, one or two inches in length, of various thicknesses, very hard, rough, and solid, of a reddish-brown color externally, and pale within ; and has numerous long, slender, yellowish fibers attached to its inferior part. It has an aromatic odor, and a warm, slightly bitter, pungent taste. Alcohol or boiling water, extracts its sensible qualities. The tincture reddens litmus paper, and yields a precipitate on the addition of water. The root has not been analyzed, but contains starch, volatile oil, resin, and bitter extractive. The root of the shops is probably derived from several other species than the officinal, which possess similar virtues, as D. Brasiliensis, D. Houstoni, D. Drakena. Some writers suppose the D. Brasiliensis, growing in Brazil, to furnish the true root. Contrayerva, in the Spanish American language, means antidote, having the power to counteract the effects of poisons.
Properties and Uses. — Stimulant, tonic, and diaphoretic. Has been used in low states of fever, malignant eruptive diseases, some forms of dysentery and diarrhea, and other diseases requiring gentle stimulation. Dose of the powdered root, thirty grains. The best form of administration is the infusion. It is seldom used in this country, having been superseded by the Serpentaria.