Bailey, L.H. & Bailey, E.Z. (1976) Hortus Third. A concise Dictionary of Plants Cultivated in the United States and Canada Macmillan Publishing Co, Inc., New York
Description of the genus
Monoecious climber, with a tuberous root, bearing tendrils. Flowers cream or greenish-white. Male inflorescence a raceme of numerous flowers. Female inflorescence axillary, consisting of 1-2 flowers. Fruit large, thick, often ± pear-shaped, sometimes spiny.