Species of this genus are originally native to the western Hemisphere, but not Michigan. The history of the cultivated species is complex. Some taxa have been grown for ornament (especially the hard-shelled gourds) and others for the large edible fruits (squashes and pumpkins), part of the traditional corn-bean-squash agriculture of pre-Columbian civilizations in North and Central America.
1. Leaf blades triangular-ovate (clearly longer than broad), not deeply lobed, very stiff and rough on both sides; perennial from a large root, adventive in dry disturbed ground.
1. Leaf blades ± orbicular to reniform (broader than long), unlobed to deeply palmately lobed, thin and flexible; annual, rarely escaped from cultivation.
2. Fruiting peduncle ± terete, spongy, not expanded; leaves not lobed.
2. Fruiting peduncle ± angled, hard, expanded at junction with fruit; leaves usually lobed.
All species found in Cucurbita
MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. May 30, 2017. http://michiganflora.net/genus.aspx?id=Cucurbita.