Yam, Wildotanical: Dioscorea Villosa (LINN.)
Family: N.O. Dioscoreaceae
Synonyms: Dioscorea. Colic Root. Rheumatism Root. Wilde Yamwurzel.
Part Used: Dried rhizome.
Habitat: Southern United States and Canada.
Description: There are upwards of 150 varieties of Dioscorea, many, like the potato, being edible. An Indo-Chinese species is used as a dye in Southern China. Dioscorea Villosa is a perennial, twining plant, with long, knotty, matted, contorted, ligneous root-stocks. The root is long, branched, crooked, and woody, the taste being insipid, afterwards acrid, and having no odour. It is usually sold in pieces of various lengths, which are difficult to pulverize, as the root flattens out when this is attempted. The therapeutical value is lost after the first year, so that it should be freshly gathered and carefully dried each year.
Constituents: Much saponin has been found in the roots, and a substance improperly called dioscorein, obtained by precipitating the tincture with water.
Medicinal Action and Uses: Antispasmodic. Perhaps the best relief and promptest cure for bilious colic, especially helpful in the nausea of pregnant women. Valuable also in painful cholera morbus with cramps, neuralgic affections, spasmodic hiccough and spasmodic asthma.
Dosage: 1/2 to 1 drachm of fluid extract. Dioscorein, 1/4 to 4 grains.
Poisonous, if any, with Antidotes: An alkaloid separated from the Javanese D. hirsuta has been found to be a convulsive poison, resembling picrotoxin, but much feebler.