Cucurbita pepo

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.<ref>Template:Cite web</ref>

It has been domesticated in the Americas for thousands of years,<ref>Template:Cite web</ref> 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.<ref>Template:Cite web</ref> Some authors maintain that C. pepo is derived from C. texana, while others suggest that C. texana is merely feral C. pepo.<ref name=nee>Template:Cite journal</ref> 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.<ref name="deckerwalters">Template:Cite journal</ref>

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.<ref name="cane">Template:Cite web</ref>

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 Template:Convert high and Template:Convert wide, with yellow flowers.<ref>Template:Cite web</ref> 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.<ref name="paris1989">Template:Cite journal</ref> Parthenocarpy is known to occur in certain cultivars of C. pepo.<ref name="robinsonreiners">Template:Cite journal</ref><ref name="menezes">Template:Cite journal</ref>

The leaves have three to five lobes and are Template:Convert 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.<ref name="nee" /><ref name="gibbonames238">Template:Cite book</ref><ref name="tamu">Template:Cite web</ref> 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.<ref name="nee" /><ref name="gibbonames238" /><ref name="tamu" />

Before the arrival of Europeans, C. pepo, along with C. moschata, had been carried over all parts of North America where they could be grown.<ref name="Boswell">Victor E. Boswell and Else Bostelmann. "Our Vegetable Travelers." The National Geographic Magazine. 96.2: August 1949.</ref> 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.<ref name="deckerwalters" /> It is one of several plants cultivated in prehistoric North America as part of the Eastern Agricultural Complex. It is known to have appeared in Missouri at least 4,000 years ago.<ref name="saade">Template:Cite web</ref> Some varieties grow in arid regions and some in moist regions.<ref name="deckerwalters" /> Many of these peoples, particularly in the west, still grow a diversity of hardy squashes and pumpkins not to be found in commercial markets.<ref name="Boswell" /> Still, neither C. pepo nor C. moschata had been carried into South America as had beans, which originated in the same general region.<ref name="Boswell" />

Debates about the origin of C. pepo have been going on since at least 1857.<ref name="kirkpatrick">Template:Cite journal</ref> 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.<ref name="saade" /><ref name="andres2">Template:Cite journal</ref><ref name="sanjur">Template:Cite journal</ref><ref name="soltis">Template:Cite book</ref>

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.<ref name="deckerwalters" />

Several taxa have been proposed, but as of 2012 none has been universally accepted.<ref name="kim">Template:Cite book</ref> In 2002, the taxa conventions proposed by Decker-Walters were:<ref name="deckerwalters" />

C. pepo subsp. pepo - cultivated pumpkins, marrows, the orange gourds ("Orange Ball" and "Orange Warted")
C. pepo subsp. ovifera var. ovifera – cultivated crooknecks, scallops, acorns, most ornamental gourds
C. pepo subsp. ovifera var. ozarkana – wild populations in the Greater Mississippi Valley and Ozark Plateau
C. pepo subsp. ovifera var. texana – wild populations in Texas
C. pepo subsp. fraterna – wild populations in northeastern Mexico

A 2003 study recognized three subspecies:<ref name="paris">Template:Cite journal</ref>

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.<ref name="paris1989" /><ref name="paris1986">Template:Cite journal Template:Dead link</ref> All but a few C. pepo cultivars can be included in these groups.<ref name="paris1986" /> These eight edible cultivated varieties of C. pepo vary widely in shape and color,<ref name="saade" /><ref name="mbccp">Template:Cite web</ref><ref name="heistinger">Template:Cite book</ref> and one inedible cultivated variety:<ref name="decker">Template:Cite journal</ref>

Cultivar group	Botanical name	Description
Acorn	C. pepo var. turbinata	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,<ref name="paris1986" /> ex: Acorn squash<ref name="saade" /><ref name="mbccp" /><ref name="heistinger" />
Cocozelle	C. pepo var. longa	summer squash, long round slender fruit that is slightly bulbous at the apex,<ref name="paris1986" /> similar to fastigata, ex: Cocozelle von tripolis<ref name="saade" /><ref name="mbccp" /><ref name="heistinger" />
Crookneck	C. pepo var. torticollia	summer squash, shrubby plant, with yellow, golden, or white fruit which is long and curved at the end and generally has a verrucose (wart-covered) rind,<ref name="paris1986" /> ex: Yellow crookneck squash<ref name="saade" /><ref name="mbccp" /><ref name="heistinger" />
Pumpkin	C. pepo var. pepo	winter squash, creeping plant, round, oblate, or oval shape and round or flat on the ends,<ref name="paris1986" /> ex: Pumpkin;<ref name="saade" /><ref name="mbccp" /><ref name="heistinger" /> includes C. pepo subsp. pepo var. styriaca, used for Styrian pumpkin seed oil<ref name="fürnkranz">Template:Cite journal</ref>
Scallop	C. pepo var. clypeata; called C. melopepo by Linnaeus<ref name="deckerwalters" />	summer squash, prefers half-shrubby habitat, flattened or slightly discoidal shape, with undulations or equatorial edges,<ref name="paris1986" /> ex: Pattypan squash<ref name="saade" /><ref name="mbccp" /><ref name="heistinger" />
Straightneck	C. pepo var. recticollis	summer squash, shrubby plant, with yellow or golden fruit and verrucose rind, similar to var. torticollia but a stem end that narrows,<ref name="paris1986" /> ex: Yellow summer squash<ref name="saade" /><ref name="mbccp" /><ref name="heistinger" />
Vegetable marrow	C. pepo var. fastigata	summer and winter squashes, creeper traits and a semi-shrub, cream to dark green color, short round fruit with a slightly broad apex,<ref name="paris1986" /> ex: Spaghetti squash (a winter variety)<ref name="saade" /><ref name="mbccp" /><ref name="heistinger" />
Zucchini (US) Courgette (UK, IE)	C. pepo var. cylindrica	summer squash, presently the most common group of cultivars, origin is recent (19th century), semi-shrubby, cylindrical fruit with a mostly consistent diameter,<ref name="paris1986" /> similar to fastigata, ex: Zucchini<ref name="saade" /><ref name="mbccp" /><ref name="heistinger" />
Ornamental gourds	C. pepo var. ovifera	non-edible,<ref name="decker" /> field pumpkins closely related to C. texana, vine habitat, thin stems, small leaves, three sub-groups: C. pepo var. ovifera (egg-shaped, pear-shaped), C. pepo var. aurantia (orange color), and C. pepo var. verrucosa (round warty gourds), ornamental gourds found in Texas and called var. texana and ornamental gourds found outside of Texas (Illinois, Missouri, Arkansas, Oklahoma, and Louisiana) are called var. ozarkana.<ref name="tamu" />

Random amplified polymorphic DNA has proven useful in sorting out the relationships of the C. pepo species, varieties, and cultivars, showing that few, if any, modern cultivars have their origins with C. texana. They are associated with C. fraterna or a still-unknown ancestral specimen in southern Mexico.<ref name="deckerwalters" />

It has been proposed that the domesticated forms of C. pepo are a compilospecies of C. pepo subsp. fraterna and C. pepo subsp. texana.<ref name="andres2" /><ref name="sanjur" /> A 1989 study on the origins and development of C. pepo suggested that the original wild specimen was a small round fruit and that the modern pumpkin is its direct descendant. This investigation proposed that the crookneck, ornamental gourd, and scallop are early variants, and that the acorn is a cross between the scallop and pumpkin.<ref name="paris1989" />

Based on genetic allele analysis, two distinct groups occur within domesticated C. pepo: pumpkin, calabaza, criolla, and marrow squash are in one; and ornamental gourds, crookneck, acorn, scallop, and a few others in the second one. C. pepo subsp. fraterna is genetically closer to the first group and C. pepo subsp. texana is genetically closer to the second group.<ref name="soltis" /><ref name="smith">Template:Cite book</ref>

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.<ref name="bailey">Template:Cite journal</ref><ref name="nee" /><ref name="grin">Template:GRIN</ref> The isozymes are similar between Cucurbita pepo subsp. pepo, and all studied C. fraterna alleles are also found in C. pepo subsp. pepo.<ref name="andres2" /> It is native to Tamaulipas and Nuevo León, Mexico. This subspecies has not been domesticated.<ref name="nee" /> It is considered to be the progenitor and nearest relative of the domesticated subspecies C. pepo subsp. pepo which is found in the same areas as C. pepo subsp. fraterna. It was first formally described by Liberty Hyde Bailey in 1943, in Gentes Herbarum.<ref name="bailey" />

Unlike most wild Cucurbita, some specimens of C. fraterna have been found without bitter fruit. Its usual habitat is dry upland scrub areas. It blooms in September and fruits ripen in December.<ref name="nee" />

Subspecies texana

This subspecies was formerly considered a separate species C. texana by some authorities before being reclassified as a subspecies of C. pepo. A common name is Texas gourd. This subspecies is mesophytic and native to Texas, primarily the southeastern region where it can be found in or near sandy riverbeds.<ref name="nee" /> It is found only in the wild.<ref name="tamu" /> It is possibly a progenitor and close relative of the domesticated subspecies Cucurbita pepo subsp. ovifera, though they are native to different areas. The fraterna subspecies is also closely related. It was first collected 1835 by J. L. Berlandier in southern Texas. It was formally described as Tristemon texanus by George Heinrich Adolf Scheele in 1848 and transferred to the genus Cucurbita by Asa Gray in 1850.<ref name="IPNI">Template:Cite web</ref><ref name="tamu" />

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Distribution and habitat

The species is found from sea level to slightly above Template:Convert.

Uses

Fresh squash is cut into spiral strips, folded into hanks and hung up to dry for winter use. The blossoms are cooked in grease <ref>Template:Cite web</ref> 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, and dippers and put to various uses.<ref name="Stev1915">Stevenson, Matilda Coxe, 1915, Ethnobotany of the Zuni Indians. SI-BAE Annual Report #30</ref> The gourds are also worn in phallic dances by the Zuni symbolizing fructification or made into ceremonial rattles, made into receptacles for storing precious articles, and a poultice of seeds and blossoms is used for treating cactus scratches.<ref name="Stev1915" />