Wild Yam
Dioscorea villosa

Family: Dioscoreaceae

What it is like

Dioscorea villosa is a PERENNIAL CLIMBER growing to 3 m (9ft 10in). See above for USDA hardiness. It is hardy to UK zone 6. It is in flower from September to October. The species is dioecious (individual flowers are either male or female, but only one sex is to be found on any one plant so both male and female plants must be grown if seed is required). . The plant is not self-fertile. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and prefers well-drained soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It cannot grow in the shade. It prefers moist soil.

Height (m): 3

Where it is found

Borders of bogs, swamps, marshes, river and lake margins, creek bottoms, sandy or rocky soils, moist or dry woods, hammocks, thickets, limestone or talus slopes, roadsides, sea level to 1500 m.

Eastern N. America - New England to Minnesota and Ontario, south to Virginia and Texas.

Conservation Status:

Countries/locations it is found in

How it is used

Food

Rating: 2

Tuber - cooked. Some caution should be exercised with this plant. See 'Medicinal Uses' for more information.

Root: includes bulbs, corms, tubers, rhizomes etc.

Medicine

Rating: 4

Wild yam roots, and the roots of many other members of the genus, contains diosgenin. This is widely used in modern medicine in order to manufacture progesterone and other steroid drugs. These are used as contraceptives and in the treatment of various disorders of the genitary organs as well as in a host of other diseases such as asthma and arthritis. The roots are anti-inflammatory, antispasmodic, cholagogue, diaphoretic and vasodilator. They are also a visceral relaxant. This plant affords one of the best and fastest cures for bilious colic, it is especially helpful in treating the nausea of pregnant women and has been used to ease the pain of childbirth. It is also taken internally in the treatment of arthritis, irritable bowel syndrome, gastritis, gall bladder complaints, painful menstruation etc. The root is harvested in the autumn and dried for later use. The root should not be stored for longer than 1 year, since it is likely to lose its medicinal virtues. Caution is advised in the use of the this plant, when taken fresh it can cause vomiting and other side effects. The root, harvested in September, is used to make a homeopathic remedy. Its main use is in the treatment of infant colic.

Antiinflammatory: Reduces inflammation of joints, injuries etc.

Antirheumatic: Treats rheumatism.

Antispasmodic: Relaxes muscular spasms and cramps, calming nervous irritation.

Cholagogue: Increases the flow of bile and its discharge from the body.

Contraceptive: Prevents fertilization occurring in females.

Diaphoretic: Induces perspiration.

Homeopathy: A plant used in homeopathic treatments.

Vasodilator: Widens the blood vessels, thereby reducing blood pressure.

Other

Rating:

How it is grown

An easily grown plant, succeeding in a fertile well-drained soil in a sunny position or light shade. Prefers a rich light soil. Plants are hardy to at least -15°c. Plants produce tubercles (small tubers that are formed in the leaf axils of the stems), and can be propagated by this means. A climbing plant that supports itself by twining around the branches of other plants. This is a highly polymorphic species, some botanists dividing it up into several species. Dioecious. Male and female plants must be grown if seed is required.

Propagating it: Seed - sow March to April in a sunny position in a warm greenhouse and only just cover. It germinates in 1 - 3 weeks at 20°c. Prick out the seedlings as soon as they are large enough to handle and grow on in a greenhouse for their first year. Plant out in late spring as the plant comes into new growth. Basal stem cuttings in the summer. Division in the dormant season, never when in growth. The plant will often produce a number of shoots, the top 5 - 10 cm of the root below each shoot can be potted up to form a new plant whilst the lower part of the root can possibly be eaten. Tubercles (baby tubers) are formed in the leaf axils. These are harvested in late summer and early autumn when about the size of a pea and coming away easily from the plant. They should be potted up immediately in individual pots in a greenhouse or cold frame. Plant out in early summer when in active growth.

Best place to grow: Woodland Garden Sunny Edge; Cultivated Beds;

Habit: Perennial Climber

Hardiness: 5-9

Growth:

Soil: Light (sandy), medium, heavy (clay)

Shade: No shade

Moisture: Moist

Things to keep in mind

Edible species of Dioscorea have opposite leaves whilst poisonous species have alternate leaves. Use of the fresh plant can cause vomiting and other side effects. Known to cause headaches, menstrual irregularities & acne. May cause hair loss & oily skin. Avoid during pregnancy. Avoid in patients with cancers of the breast, ovaries, prostate & uterus .

Its other names

Local names

Synonyms

Dioscorea cliffortiana Lam. Dioscorea hexaphylla Raf. Merione villosa (L.) Salisb.