- Dioscorea villosa L.
- Yam family
Parts Usually Used
Dried root (rhizome)
Description of Plant(s) and Culture
Wild yam is a perennial vine; the long, slender, knotted, contorted,
woody, tuberous rootstock is crooked and laterally branched and twining
stems. Broadly ovate and cordate, the heart-shaped, leaves are from
2-6 inches long and about three-fourths as wide, glabrous on top,
and finely fairy underneath on long stems. They are usually alternate,
but the lower leaves sometimes grow in twos and fours. The tiny, greenish-yellow
flowers, cinnamon scented, grow on branched stalks from the axils
of the leaves, male and female on separate plants, blooms during June
and July, the male flowers in drooping panicles, the female in drooping
spicate racemes. The fruit is a three-winged (triangular) capsule
containing winged seeds.
There are nearly 150 varieties of Dioscorea many of them developing
edible tubers like potatoes. An ornamental variety is D. batatas,
sometimes known as the Chinese yam, the red velvet yam, or the cinnamon
yam. In using D. villosa, do not confuse oriental tonic wild yams.
Grows in the United States from Rhode Island to Minnesota, Florida
and Texas. Twining in thickets, over fences, over trees and shrubs
in the woods, in hedges and over bushes, the thin, woolly, reddish-brown
stem grows from 5-18 feet long.
Analgesic, antibilious, antispasmodic, aphrodisiac, diaphoretic,
diuretic, expectorant, emetic in large doses, hepatic, nutritive tonic
Glycoside saponins and diosgenin, which are hormone precursors, especially
progesterone and other cortical steroids that effect the female menstrual
cycle and help to reduce pain.
Legends, Myths and Stories
Used to make the original contraceptive pills when synthetic hormone
production was not a commercial proposition. Mexican wild yam (D.
villosa) contains hormonal substances very similar to progesterone.
It also relaxes smooth muscle; hence another of its common names,
colic root (Alestris farinosa L.). Many other yams are used as a starter
arterial to produce hydrocortisones for non-prescription eczema creams.
It was once commonly prescribed for bilious colic.
Wild yam is said to be soothing to the nerves and beneficial for neuralgia,
neuritis, and pains in the
urinary tract. Some have considered it an antispasmodic, for pain,
and recommended it for cramps.
Is effective for the liver and gall
During pregnancy, small frequent doses will help allay nausea.
It will help expel gas from the stomach and bowels. Relieves gastrointestinal
irritations, asthma, spasmodic
hiccough, and "chronic gastritis of drunkards". Contains diosgenin,
used to manufacture progesterone and other steroid drugs. Most of
the steroid hormones used in modern medicine, especially those in
contraceptives, were developed from elaborately processed chemical
components derived from yams. Drugs made with yam-derived components
(diosgenins) relieve arthritis,
eczema, regulate metabolism
and control fertility. Synthetic products manufactured from diosgenins
include human sex hormones (contraceptive pills), drugs to treat menopause,
impotency, prostate hypertrophy,
and psycho-sexual problems, as well as high
blood pressure, arterial spasms, migraines,
and other ailments. Widely prescribed cortisones and hydrocortisones
were indirect products of the genus Dioscorea. They are used for Addison's
disease, some allergies,
bursitis, contact dermatitis, psoriasis,
recluse spider bites, insect
These steroid-like substances and this may explain why it relieves
rheumatism pains, and other
It can be taken to relieve muscle
spasms. Native Americans used wild yam to relieve labor pains.
Formulas or Dosages
Infusion: steep 1 tsp. root in 1 cup water for 30 minutes.
Take 1 cup in the course of a day, a mouthful at a time.
Tincture: take 10-30 drops in water, 3-4 times a day as needed.
Fresh plant may induce vomiting and other undesirable side effects.
In using, do not confuse oriental tonic wild yams.
Care should be taken when using this herb if there is an excess of
mucous or congestion in the body.
Avoid large doses of D. villosa in pregnancy unless under medical
supervision; may be taken during labor.