A large twining or creeping vine with relatively thick stems covered with long yellowish-brown hairs. Its thickened roots develop into large tubers (up to 1.8 m long and 15 cm wide). Its very large alternately arranged leaves have three lobed or un-lobed leaflets (7-20 cm long and 5-13 cm wide). Its pea-shaped flowers (12-20 mm long) are arranged in elongated clusters in the leaf forks. These flowers are; purple, blue, pink or violet in colour with a yellow spot near their centres. Its fruit is an elongated and flattened pod (5-12 cm long) that is densely covered in rusty-coloured hairs.