Wild yam root: A Bit of Botany
a little botanical information on wild yam

Dioscorea composita
Dioscorea composita, or wild yam, is a member of the Dioscoreaceae family.

Wild yam is a twining vine, meaning it supports itself by wrapping around trees or sturdy plants since it can not stand on its own.

Its characteristic branched rhizomes are woody, knotted, elongated, and curved. They have thin, reddish-brown colored stems that can reach lengths of up to 12 meters. Wild yams do not have the large and soft, fleshy tubers of the sweet potato nor the types of yams that are used primarily for food. Instead the wild yam produces very dry and narrow rhizomes. These are twisted and knotty and they bear horizontal branches of long creeping runners.

Wild yam's broad heart-shaped leaves are large and flat; the plant's yellowish-white flowers are small and vanilla-scented. The upper side of the leaves is smooth and the underside is downy. Tiny tubercles grow where the leaves branch from the plant.

The plant's early-summer-blooming flowers are dioecious and are followed by small greenish fruits. These will turn brown and remain clinging to the vine during the winter.

Dioscorea villosa

Dioscorea villosa is a member of the Dioscoreaceae family. It is a is a deciduous perennial herbaceous twining plant that grows (in a clockwise direction) over small shrubs. The upper leaves are alternate, heart-shaped and shiny with long petioles, entire margins, prominent veins and acuminated apices. The lower leaves are usually in whorls.

The plants are dioecious. Small staminate (male) flowers are white and fragrant, and are in panicles, while carpelate (female) plants have small single flowers at the leaf nodes. The fruit is a membraneous 3-valved capsule with one or two brown winged seeds in each locule. The long, rhizomes are cylinder-shaped and grow to 5-10 mm in diameter, with many tough, slender roots underneath.

Dioscorea composita &
Dioscorea villosa
common names & nomenclature
Named after the Greek physician Dioscorides.

Also known as:
wild yam, colic root, rheumatism root, china root, yuma, devil's bones, african nyami, chinese yam, barbasco

Wild yam root: Cultivation & Harvesting
considerations for growing and harvesting wild yam

Dioscorea composita &
Dioscorea villosa
Wild yam can be found growing in sunny woodland garden edges, thickets, swamps, and cultivated beds in warm temperate to tropical climates.

Grows well in a fertile well-drained soil. Prefers a rich light soil.

Divide plants 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.

Baby tubers (tubercles) are formed in the leaf axils. Harvest these in late summer and in the early autumn when the tubercles are about the size of a pea and come away easily from the plant. Pot up immediately in individual pots in a greenhouse or cold frame. Plant out in early summer when in active growth. Can also propagate by seed.

The root is harvested in the autumn and dried for later use.

Store the dried wild yam root pieces or dried wild yam root powder in an airtight container in a cool, dry place. The root should not be stored for longer than 1 year.

Wild yam root: Where in the World
habitat and range for wild yam

Dioscorea composita

The Dioscorea composita yam species is native to Mexico.

Dioscorea villosa

While the Dioscorea villosa yam species is native to eastern North America, New England to Minnesota, south to Virginia and Texas.