winter squash cultivar Cucurbita moschata Cucurbita pepo Winter squash is an annual fruit representing several squash species within the genus Cucurbita. It differs from summer squash in that it is harvested and eaten in the mature fruit stage when the seeds within have matured fully and the skin has hardened into a tough rind. At this stage, most varieties of this fruit can be stored for use during the winter. cucurbita maxima curcurbita winter squash squash plant