Yam (Dioscorea species)
These plants are twining, tuberous vines that creep along the ground or occasionally climb trees and other structures. The woody rootstock, or tubers, is pale brown, knotty, and cylindrical in shape. Stems are reddish-brown and can grow to over 30 feet in length. They have broad, alternate, heart- or arrow-shaped leaves that are spirally arranged on long stems. The leaves are deep veined (may give the leaves a puckered look) with veins beginning at the base (where the stem meets) and running towards the tip. Flowers grow in clusters and are small, greenish-white or greenish-yellow with six petals. The fruit is a capsule in most species but can be a soft berry in some species. Their rootstock may be very large and weigh many kilograms.
Where to Find: True yams are restricted to tropical regions where they are an important food crop. Look for yams in fields, clearings, and abandoned gardens. They are found in rain forests, semi-evergreen seasonal forests, and scrub and thorn forests in the tropics. In warm temperate areas, they are found in seasonal hardwood or mixed hardwood-coniferous forests, as well as some mountainous areas.
Edible Parts: Most yams are toxic if eaten fresh. Boil the rootstock and eat it as a vegetable.
Other Uses: The Wild Yam is used as a herbal treatment for many ailments.