Chinese yam

Dioscorea polystachya Turcz.

Dioscorea polystachya is an invasive herbaceous, twining vine that grows to about 16.4 ft. (5 m). It invades open to shady areas in the Eastern United States.
The leaves are alternate proximally but can become opposite as they advance up the vine. They are about 8 in. (20.3 cm) long, wide, and heart to fiddle shaped (margins three-lobed), with prominent, parallel veins. The petiole base is not clasping. Leaves are usually more rounded when young or on young plants and fiddle shaped farther along the stem and on older plants. The rounded stems are thin and wiry.
The staminate plants may produce small, white flowers annually.
The seeds are winged all around, but the chief means of reproduction are aerial, potato-like tubers (bulbils) located at the leaf axils and underground tubers.
Ecological Threat
Dioscorea polystachya can form dense masses of vines that cover and kill native vegetation, including trees, within a variety of moist, disturbed habitats. It was introduced from Asia for ornamental, food, and medicinal purposes and escaped cultivation in the mid-1990s.

Identification, Biology, Control and Management Resources

Nonnative Invasive Plants of Southern Forests - USDA Forest Service
Southeast Exotic Pest Plant Council Invasive Plant Manual - SE-EPPC
Element Stewardship Abstract - The Nature Conservancy
Weed of the Week - USDA Forest Service
Plant Invaders of Mid-Atlantic Natural Areas - National Park Service