Pumpkins contain seeds and they're classified as fruits. They belong to the gourd family known as Cucurbitaceae.
Cucurbitaceae family consists of Cucurbita (pumpkins, Winter & Summer squashes), Lagenaria (calabash or bottle gourd), Citrullus (watermelons), Cucumis (cucumbers) and Luffa (loofah).
The most known Cucurbita species:
-Cucurbita argyrosperma (Japanese pie pumpkin or cushaw pumpkin)
-Cucurbita ficifolia (Figleaf gourd)
-Cucurbita moschata (Aehobak, Butternut squash, Calabaza, Dickinson pumpkin, Giromon, Golden Cushaw, Loche, Long Island cheese pumpkin, Musquée de Provence or Moscata di Provenza, Naples long squash, Seminole pumpkin, Tromboncino)
-Cucurbita maxima (giant pumpkins, we all know from the county fairs, but also: Arikara squash, Banana squash, Boston marrow, Buttercup squash, Candy Roaster squash, Hubbard squash, Jarrahdale pumpkin, Kabocha, Lakota squash, Nanticoke squash, Turban squash).
Please note: Cucurbita maxima originated from Cucurbita andreana.
-Cucurbita pepo (regular sugar & carving pumpkins, ornamental squashes like acorn and patty pan squash, various Summer & Winter squashes like Spaghetti and Delicata Squash).