Also known as colic root, wild yam is a twining, tuberous vine native to North America. It is one of an estimated 600 species of yam in the genus Dioscorea, many of them wild species that flourish in damp woodlands and thickets. Wild yam is a perennial, twining vine with pale brown, knotty, woody cylindrical rootstocks, or tubers. The rootstocks are crooked, and bear horizontal branches of long creeping runners. The thin reddish-brown stems grow to a length of over 30 feet. The roots initially taste starchy, but soon after taste bitter and acrid.
The wild yam plant has clusters of small, drooping greenish-white and greenish-yellow flowers. The heart-shaped leaves are long and broad and long-stemmed, with prominent veins. The upper surface of the leaves is smooth while the underside is downy.
