The hairs from the pods of Mucuna pruriens, De Candolle (Mucuna prurita, Hooker; Dolichos pruriens, Linné; Stizolobium pruriens, Persoon; Carpopagon pruriens, Roxburgh).
COMMON NAMES: Cowhage, Cowage (Seta siliquae hirsutae).
ILLUSTRATION: Bentley and Trimen, Med. Plants, 78.
Botanical Source.—This is a perennial plant, with a fibrous root and a twining, herbaceous, much-branched stem, and of considerable length. The leaves are alternate, pinnately trifoliate, distant, and on long petioles; leaflets entire, ovate, acute, smooth above, hairy beneath; lateral ones oblique at the base, middle one slightly rhomboidal. The flowers are rather large, have a disagreeable, alliaceous odor, are disposed in axillary, lax, many-flowered, interrupted racemes, 1 to 1 ½ feet long. The corolla is papilionaceous; vexillum cordate, incumbent on the wings, much shorter than they and the keel, without callosities, and flesh-colored; wings oblong-linear, connivent, purple, or violet; keel or carina straight below, slightly falcate in the upper part, terminated by a smooth, polished, acute beak, and greenish-white. Stamens diadelphous (9 and 1), alternately longer; anthers alternately longer and ovate. Calyx campanulate, bilabiate, with 2 very caducous bracteoles as long as the tube, hairy, pink, bilabiate, with narrow lanceolate segments; upper lip broad, entire, or emarginate; lower, trifid, middle segment the largest. Style long, slender, and hairy below; stigma small. The legume is about 3 inches long, as thick as the finger, and closely covered with strong, brown, stinging hairs. The seeds are oblong and variegated, with a white hilum (L.).
History, Description, and Chemical Composition.—This plant inhabits the West Indies, and other tropical parts of South America; it is found in woods along river courses, upon fences, and in waste, neglected places. The medicinal part of the plant is the hair of the pods, which are generally imported into this country attached to the pod, and from which they are carefully removed, so that they do not fasten to the operator's hands. They are straight, about ⅛ of an inch in length, quadrangularly prismatic, with upper half retrorsely serrated, and acutely pointed at the apex. They are brown and glossy, and inclose a granular brown substance, which but partially fills the hair. Mucuna, according to Martius (1827), contains resin and a small amount of tannin. The shorter, darker-hued spicula of the Stizolobium urens, Persoon (Mucuna urens, De Candolle; Dolichos urens, Linné), is used for the same purposes as cowhage. The seeds of this species are employed in dysuria in the West India Islands. In India the root of the cowhage plant is a reputed remedy for cholera. Mucuna was first introduced to the notice of English physicians by Bancroft, about the year 1769 (see Dymock's Vegetable Materia Medica of India, p. 229).
Action, Medical Uses, and Dosage.—Cowhage was formerly regarded as a mechanical anthelmintic, acting by irritating the body of the worms; its decoction or tincture has no anthelmintic properties. It was used in the treatment of intestinal worms, which are expelled alive. It is very probable, however, that its setae did very little mechanical harm to the worm, for when the spiculae are moistened, they largely lose their irritating properties. It has no effect on taenia, but appears more serviceable in removing the lumbrici and ascarides. Dose, from 1 drachm to ½ ounce, in syrup or molasses, and followed a few hours afterward by a purgative. The application of oil is the best to allay the heat and itching it produces when rubbed on the skin. Cowhage has been recommended in the form of an ointment, as a cutaneous irritant, in the place of croton-oil and tartar-emetic; also as a good medium for the endermic application of various substances, as hydrochlorate of morphine. The proportions are, 7 ½ grains of the hairs of cowhage to 1 ounce of lard. This must be rubbed in from 10 to 20 minutes; 7 or 8 grains are usually sufficient. The immediate effect is the production of a sensation resembling stinging with nettles; but the burning sensation, and the itching diminish during the friction, and entirely pass off in less than half an hour. The skin generally becomes covered with white, flat papulae, which soon disappear, leaving a sensation of heat. It produces no inconvenience, and children bear it easily. It is seldom used.
Related Species.—The following species of Corylus are indigenous to (one cultivated in) the United States, one of which has covering the involucre spiculae, which are employed like mucuna, as a vermifuge. They belong to the natural order Cupuliferae.
Corylus rostrata, Aiton, Beaked hazel.—Canada, northern United States, and along the Appalachian ranges. Shrub 2 to 5 feet high. Fruit inclosed in along, scaly involucre, which is hirsute, and terminates in a prolonged, tube-like beak. The spiculae are reputed to act as a mechanical vermifuge.
Corylus americana, Walter.—North American thickets. Fruit wide and long, surrounded by an involucre at least double the length of the fruit.
Corylus avellana, Linné, Hazel.—Europe, North Asia, in wood and thickets. Cultivated in the United States. A shrub, from 10 to 15 feet high, flowering in early spring and bearing fruit in the autumn. The fruit is known as the filbert, and is a hard nut, with a pale-brown, ligneous shell, surrounding a sweetish, oleaginous, white kernel. It is about an inch long. The seeds yield about 50 per cent of hazelnut oil, a light-yellow, fixed oil, without odor, but tasting somewhat like the nuts. It is composed of olein, palmitin, arachin, and stearin, freezing at near the zero point, 0° F. (-17.8° C.).