any of several tropical climbing plants in the genus Sicyos, of the gourd family (Cucurbitaceae). One species (S. angulatus), known also as star cucumber, is native to North America. A bur cucumber has sharply lobed leaves, forked tendrils, clusters of five-petaled white flowers that are borne at the ends of long stalks that arise from the leaf axils, and clusters of oval, prickly, single-seeded fruits.