Cucurbita pepo encompasses many varieties, including pumpkins and winter squash, but it also has the whole range of summer squash as well. One of the better known varieties in the summer category might be the heirloom Yellow Crookneck, which grows as a substantial bush, not a vining squash. When small, the fruit is smooth with the obvious curved neck already formed, but as it matures, it develops a bumpy, warty appearance while the color deepens and the skin toughens. Needless to say, the squash is best picked small to be eaten fresh (although, depending on the strain purchased, some seed growers have worked to smooth out some of the lumps on the slightly more mature fruit). However, if you miss a few, they can be left to age and used as ornamental gourds.