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''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 ''Cucurbita pepo'' subsp. ''pepo'', called summer squash.〔(【引用サイトリンク】title=Cucurbita pepo L.field pumpkin )〕 It has been domesticated in the New World for thousands of years.〔(【引用サイトリンク】title=Cucurbits )〕 The Zuni people have several uses for this plant. 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 and for medical conditions. ''C. pepo'' seems to more closely related to ''C. fraterna'', though disagreements exist about the exact nature of that connection, too. == Taxonomy == The morphological differences within the species ''C. pepo'' are so vast, its various subspecies and cultivars have been misidentified as totally separate species. These vast differences are rooted in its widespread geographic distribution.〔 ''C. pepo'' is one of the oldest, if not the oldest domesticated species.〔〔(【引用サイトリンク】url=http://botany.csdl.tamu.edu/FLORA/flcp/flcp3.htm )〕 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.〔〔〔 Its ancient territory extended north into Texas and up the Greater Mississippi River Valley into Illinois and east to Florida, and possibly even to Maine.〔 It is known to have appeared in Missouri at least 4,000 years ago. Some varieties grow in arid regions and some in moist regions.〔 Debates about the origin of ''C. pepo'' have been going on since at least 1857. Traditionally, two opposing theories are given about its origin: 1) ''C. pepo'' is a direct descendant of ''C. texana'' and 2) ''C. texana'' is feral ''C. pepo''.〔 A more recent theory is that is that ''C.pepo'' is a descendant of ''C. fraterna'' and hybridized with ''C. texana'';〔 resulting in two distinct domestication events in two different areas: one in Mexico and one in the eastern United States, with ''C. fraterna'' and ''C. texana'', respectively, as the ancestral species.〔〔〔 ''C. pepo'' may have appeared in the Old World prior to moving from Mexico into South America.〔 It is found from sea level to slightly above . Leaves have three to five lobes and are 20–35 cm wide. All the subspecies, varieties, and cultivars are conspecific and interfertile. 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.〔 Wild ''C. pepo'' is still found in the same areas as ''C. fraterna'' in Mexico. Their isozymes are very similar. ''C. pepo'' has more similarities to ''C. fraterna'' than it does to ''C. texana,'' which is also claimed to be an ancestor of ''C. pepo''. All studied ''C. fraterna'' alleles are also found in ''C. pepo''.〔 Consequently, ''C. fraterna'' is the nearest relative of ''C. pepo''. ''C. pepo'' is most likely an early domesticated form of ''C. fraterna''. It crosses well with both ''C. pepo'' and ''C. texana''. Unlike most wild ''Cucurbita'' species, some fruit specimens of ''C. fraterna'' have been found that were not bitter. Its usual habitat is dry upland scrub areas. ''C. pepo'' could be a compilospecies of ''C. fraterna'' and ''C. texana'', which appear to be two species that were originally separate. Based on genetic allele analysis, two distinct groups occur within ''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. fraterna'' is genetically closer to the first group and ''C. texana'' is genetically closer to the second group. Ornamental gourds found in Texas are called var. ''texana'' and those found outside of Texas (Illinois, Missouri, Arkansas, Oklahoma, and Louisiana) are called var. ''ozarkana''.〔(【引用サイトリンク】url=http://botany.csdl.tamu.edu/FLORA/flcp/flcp3.htm )〕 In a 1989 study on the origins and development of ''C. pepo'', Paris suggested that the original wild specimen was a small round fruit and that the modern pumpkin is its direct descendant. He also suggested that the crookneck, ornamental gourd, and scallop are early variants, and that the acorn is a cross between the scallop and pumpkin.〔 Several taxa have been proposed, but as of 2012 none has been universally accepted. In 2002, the taxa conventions proposed by Decker-Walters were:〔 *''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 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. These eight edible cultivated varieties of ''C. pepo'' vary widely in shape and color,〔〔(【引用サイトリンク】publisher=Missouri Botanical Garden )〕 and one inedible cultivated variety: 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Cucurbita pepo」の詳細全文を読む スポンサード リンク
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