A perennial, semi-woody, exotic vine with invasive, uncontrollable, smothering growth. Many rampantly growing, hairy vines trail, sprawl, and loosely twine from a large, central root crown. Stems can be an inch or more in diameter in southern states. New growth is soft-hairy.
Roots large, swollen tubers that can descend more than 13 feet into sandy loam soils.
Flower pea-like, grape scented, purple, to ¾ inch wide, growing in elongated clusters. Flowering is in late July to September (in full sun).
Leaves alternate, compound, with 3 dark green leaflets that are 2¾–10 inches long, with or without irregular, shallow lobes; hairy beneath.
Fruits are elongated, beanlike, hairy pods growing in clusters. Few of the seeds are viable.
Similar species: The native hogpeanut (Amphicarpaea bracteata) can look similar, but its leaves do not exceed the size of a human hand, and the small hairs on the stems are pressed against the stem and are white.