Dioscorea Villosa. Wild Yam, Colic Root, China Root.

Botanical name: 

Description: Natural Order, Dioscoreaceae. Delicate, twining vines, with large perennial and tuberous roots, ribbed leaves, dioecious and regular flowers with six stamens, and fruit as a membranous and three-angled (often winged) pod. Genus DIOSCOREA: Flowers very small, in axillary panicles or racemes. Stamens at the base of the six-parted perianth. Pod three-celled, three-winged, dehiscence loculicidal by the winged angles; seeds one or two in each cell. D. VILLOSA: Herbaceous and reddish stem, rather smooth than villous, springing from matted root-stalks, and twining over bushes to the length of ten or twenty feet. Leaves mostly alternate, sometimes nearly opposite or in fours, ovate, two to four inches long, cordate and acuminate, nine to eleven-ribbed. Flowers pale greenish-yellow, the sterile in drooping panicles, and the fertile in drooping simple racemes. July.

This plant is found through the Middle States, but is abundant southward, and scarce northward. The root is about a fourth of an inch in diameter, long, light-brown without, nearly white within, almost devoid of smell, and of a sweetish bitter taste. Water and alcohol extract its qualities.

Properties and Uses: The roots were an aboriginal remedy, and were introduced to the notice of the profession by Dr. Horton Howard though claimed by the Eclectics as dicentra and others are. It is largely relaxant and moderately stimulant, acting as an antispasmodic, and relieving nervous excitement. Its principal use has been in the various forms of wind and bilious colic, to which it is admirably adapted. It both relaxes the muscular fibers and soothes the nerves, aiding the expulsion of flatus and promoting gentle diaphoresis. It is indeed an excellent agent in all painful and flatulent troubles of the bowels, whether simple colic, or connected with cold or diarrhea. For these purposes, it is generally advisable to combine it with some agent more stimulating than itself, such as zingiber, angelica, or other aromatic. It is an ingredient of the Carminative Drops described under angelica; and it is said that cornus sericea, in small quantities, forms a good accompaniment for these cases. In painful menstruation, neuralgia of the womb, vomiting during gestation, and the painful knottings of the uterus incident to the latter stages of pregnancy, it is an excellent remedy; and may be used freely with such other and more permanent remedies as are usually given in such cases. Its action being so largely upon the nervous structures, it can be used advantageously in other and more severe spasmodic affections; and will be found of much value in false labor pains, after pains, and (combined with moderate quantities of lobelia) in spasmodic croup.

The better manner of using it is by warm infusion an ounce of the root to twenty ounces of hot water, infused for twenty minutes; dose one, to two fluid ounces every half hour in colic. Combined with ginger and asclepias, the action is admirable as a diaphoretic, as well as antispasmodic and carminative.

Pharmaceutical Preparations: I. Tincture. Crushed dioscorea, four ounces; anise seed, one ounce; alcohol of60 percent, twenty ounces. Macerate in a covered vessel for twenty-four hours, then treat by percolation, press strongly, and add enough alcohol of the same strength to make twenty ounces. A very effective and pleasant preparation for flatulent colic. Dose, half a fluid drachm to three times that quantity, in warm water, as often as may be necessary.

II. Dioscorin. This is an extract, prepared from a saturated tincture of the root, after the manner for the preparation of cypripedin. It is a light yellowish-brown powder, which slowly absorbs moisture and becomes darker and assumes a tenacious extractive form. It represents more of the stimulating than the relaxing properties of the plant. If rubbed with one-fourth its own bulk of the powdered root, its pulverulent form may be maintained; but when it assumes the extractive form, it can not again be powdered, is scarcely soluble in alcohol, and can be administered in pills. Dose, ono to three grains, at intervals of two to four hours. I have found its action rather too slow for cases of colic, though others speak in the highest terms of it in this connection. In persistent pains through the bowels, bladder, and uterus, it is an admirable remedy.

III. Fluid Extract. This is prepared by treating a pound of crushed dioscorea with diluted alcohol, and then proceeding as in the fluid extract of boneset. It represents the plant well, and is a valuable pharmaceutical preparation. Added in proportions of one part to three parts of the Cordial, it is of superior efficacy in wind colic and painful diarrhea.

The Physiomedical Dispensatory, 1869, was written by William Cook, M.D.
It was scanned by Paul Bergner at http://medherb.com