A pumpkin is a cultivar of a squash plant, most commonly of Cucurbita pepo, that is round, with smooth, slightly ribbed skin, and most often deep yellow to orange in coloration. The thick shell contains the seeds and pulp Many people think of pumpkins as little more than a Halloween decoration or a Thanksgiving pie filling. However, it may be time to rethink this plump, nutritious orange plant. Pumpkin is a highly nutrient-dense food. It is rich in vitamins and minerals but low in calories. Pumpkin seeds, leaves, and juices all pack a powerful nutritional punch.