A pumpkin is not a vegetable; it's a fruit! In fact, it's a berry. Pumpkins belong to the family Cucurbitaceae, which includes cucumbers, melons, squash, and gourds. Within this family is the genus Cucurbita which includes gourds, winter and summer squash, and all varieties of pumpkin. pumpkin is not a vegetable; it's a fruit! In fact, it's a berry. Pumpkins belong to the family Cucurbitaceae, which includes cucumbers, melons, squash, and gourds. Within this family is the genus Cucurbita which includes gourds, winter and summer squash, and all varieties of pumpkin.