Prostrate or climbing, monoecious or dioecious, herbs. Flowers white, cream, yellow or orange. Male flowers often with a prominent bract. Petals 5, free. Stamens 3, two 2-thecous, one 1-thecous or less often 2, one 3-thecous and the other 2-thecous. Female flowers solitary. Stigma 3-lobed. Fruit tuberculate, spiny, winged or ribbed, rarely smooth.