Cucurbita: A large genus of plants native to North and South America. It includes some cultivated vegetables such as summer and winter squash, pumpkins, and ornamental gourds. Fruits are called pepos and may be long or round, large or small, smooth or warty. Some species and cultivars are edible and some are not; among the edible ones, both fruit and seeds are edible. Large yellow or white flowers with five petals.