In fact, orange color sometimes helps determine what is a pumpkin. Two varieties of the same species, C. maxima , hold the records for the world's largest squash and pumpkin. The variety called squash is gray to green and larger one called a pumpkin is pinkish to orange. Shape may vary slightly, but these two freely inter-pollinate and are botanically pretty much identical. Unless you are dealing with specific rules or regulations at a show, you can pretty much interchange the words squash and pumpkin, though you can expect a fight with purists, no matter what you do.
Pumpkins are the most popular members of the squash family.
The smaller sweet pumpkin or pie pumpkin is best for cooking. The flavor and texture are much more suitable for baking and it is served up annually in pumpkin pie at Thanksgiving. Select heavy unblemished pumpkin that is free of cracks and soft spots and has a deep orange color. Harvest with at least an inch of stem remaining or it will decay quickly. Pumpkins should not be stored in the refrigerator or in a damp place.