Pumpkins are classified as a fruit of the Cucurbitaceae family, which also includes squash, gourds and melons. All varieties of pumpkin are further defined as being part of the Cucurbita genus, with the C. pepo species being the most commonly grown plant of the genus.
The Connecticut Field variety of the Cucurbita pepo species is the most popular type of pumpkin. With its light-orange color and plump body, this is the pumpkin traditionally used as jack o'lanterns. Pumpkins can also be found within the C. mixta, C. maxima and C. moschata species that contain mostly squash. Because of the close botanical classification, the names for squash and pumpkin are sometimes interchangeable depending on location and culture.