Winter squash is an annual fruit representing several squash species within the genus Cucurbita. Late-growing, less symmetrical, odd-shaped, rough or warty varieties, small to medium in size, but with long-keeping qualities and hard rinds, are usually called winter squash. They differ from summer squash in that they are harvested and eaten in the mature stage when their seeds within have matured fully and their skin has hardened into a tough rind. At this stage, most varieties of this vegetable can be stored for use during the winter. Winter squash is generally cooked before being eaten, and the skin or rind is not usually eaten as it is with summer squash.