Cucurbita pepo is a cultivated plant of the genus Cucurbita. It yields varieties of winter squash and pumpkin, but the most widespread varieties belong to the subspecies Cucurbita pepo subsp. pepo, called summer squash.
It has been domesticated in the Americas for thousands of years, from where it was spread by early colonisers to Europe and later across the rest of the Old World in the context of the Columbian Exchange. Some authors maintain that C. pepo is derived from C. texana, while others suggest that C. texana is merely feral C. pepo. They have a wide variety of uses, especially as a food source. C. pepo seems more closely related to C. fraterna, though disagreements exist about the exact nature of that connection, too.
It is a host species for the melonworm moth, the squash vine borer, and the pickleworm. They are also the preferred pollen source for squash bees, which are the primary pollinators in the Americas.
Description
Due to their varied genetic background, members of C. pepo vary widely in appearance, primarily in regards to their fruits. The plants are typically high and wide, with yellow flowers. Within C. pepo, the pumpkins, scallops, and possibly crooknecks are ancient and were domesticated separately. The domesticated species have larger fruits and larger yet fewer seeds. Parthenocarpy is known to occur in certain cultivars of C. pepo.
The leaves have three to five lobes and are wide. All the subspecies, varieties, and cultivars are conspecific and interfertile.
Taxonomy
Origin and history
C. pepo is one of the oldest, if not the oldest domesticated species. The oldest known locations are in southern Mexico in Oaxaca 8,000–10,000 years ago and Ocampo, Tamaulipas, Mexico about 7,000 years ago. The ancient territory of C. pepo extended north into Texas and up the Greater Mississippi River Valley into Illinois and east to Florida, and possibly even to Maine. Some varieties grow in arid regions and some in moist regions. Recent biosystematic investigations indicate two distinct domestication events in two different areas: one in Mexico and one in the eastern United States, with C. pepo subsp. fraterna and C. pepo subsp. texana, respectively, as the predominant ancestral species from a phylogenetic perspective.
Subdivision
The morphological differences within the species C. pepo are so vast that its various subspecies and cultivars have been misidentified as totally separate species. These vast differences are rooted in its widespread geographic distribution. In 2002, the taxa conventions proposed by Decker-Walters were:
- Cucurbita pepo subsp. fraterna
- Cucurbita pepo subsp. pepo
- Cucurbita pepo subsp. texana
In 1986, botanist Paris proposed a taxonomy of C. pepo consisting of eight edible groups based on their basic shape. All but a few C. pepo cultivars can be included in these groups. and one inedible cultivated variety:
{| class="wikitable sortable"
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! Cultivar group !! Botanical name !! Image !! Description
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| Acorn || C. pepo var. turbinata || 100px || winter squash, both a shrubby and creeping plant, obovoid or conical shape, pointed at the apex and with longitudinal grooves, thus resembling a spinning top,
|-
| Scallop || C. pepo var. clypeata; called C. melopepo by Linnaeus
Subspecies fraterna
This subspecies was formerly considered a separate species called C. fraterna by some authorities, but modern biosystematics has placed it as a subspecies of C. pepo. The isozymes are similar between Cucurbita pepo subsp. pepo, and all studied C. fraterna alleles are also found in C. pepo subsp. pepo. and used as a delicacy in combination with other foods. Fresh squash, either whole or in pieces, is roasted in ashes and used for food. In the Zuni culture, the gourds are made into cups, ladles, dippers, and storage receptacles. A poultice of seeds and blossoms was used to treat cactus scratches.