Dioscorea composita
description
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
description
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