What Exactly is a Pumpkin?
Botanical Description of a Pumpkin:
Pumpkins are annuals and are related to such common crops as cucumbers, gourds and winter squashes, which come from the genus Cucurbita. This is a genus that grows typically on vines. Pumpkins prefer warm temperatures above 70 degrees during the day and no lower than 60 degrees at night. Pumpkins typically mature and give fruit within 90 to 120 days of being planted.
There are actually four species of Cucurbita found in North America, which can be distinguished through differences in their stems. The species that includes typical Jack O’Lantern style pumpkins, Cucurbita pepo, also includes Acorn Squash, Scallop Summer Squash, Crookneck squash, and spaghetti squashes. Cucurbita maxima includes many of the yellow winter squashes, and yellowish-tinted pumpkins. Examples of Cucurbita maxima include Big Max Pumpkin, Buttercup Squash, Turban Squash, and Mammoth. Some of the largest pumpkins are found in this species. Pumpkins found within Cucurbita moshata are mostly associated with canning pumpkins. Many winter squashes are from this species as well, such as Butternut and Winter Crookneck squash. Cucurbita mixta is often considered a subgroup of Cucurbita moshata and is used as a processing squash.
Pumpkins can also be described by how they grow. There are vining pumpkins, semi-bush pumpkins, bush pumpkins, and miniature pumpkins.
This site from Purdue University has tons of information on pumpkins plus growing tips.