Cucurbita moschata is a species originating in either Central America or northern South America. It includes cultivars of squash and pumpkin. Cucurbita moschata cultivars are generally more tolerant of hot, humid weather than cultivars of Cucurbita maxima or Cucurbita pepo. They also generally display a greater resistance to disease and insects, especially to the squash vine borer. Commercially made pumpkin pie mix is most often made from varieties of Cucurbita moschata. The ancestral species of the genus Cucurbita were present in the Americas before the arrival of humans.
^ ‘Burpee’s Butterbush’ Winter Squash’s flower
Evolutionarily speaking the genus is relatively recent in origin as no species within the genus is genetically isolated from all the other species. Cucurbita moschata acts as the genetic bridge within the genus and is closest to the genus’ progenitor.