This is a delicate twining vine, with a perennial root. From this root proceeds a smooth, woolly, reddish-brown stem, the sixth of an inch in diameter, and from five to fifteen or eighteen feet long. The leaves average two to four inches in length, and about three-quarters of their length in width. They are glabrous on the upper surface, with soft hairs on the lower. The flowers are of a pale greenish yellow color, and are very small. The seeds are one or two in each cell, and flat.