The grape is the fruit of vines of the genus Vitis of the family Vitaceae; the genera Cissus and Rhoicissus also belong to this family. Classified botanically as berries, domesticated grapes grow in clusters, range in color from pale green to black, and contain sugar in varying quantities. Grapes with about 20 percent sugar are used to make wine. Other types are eaten frech, dried as raisins, or canned. Unfermented grape juice is processed for dringking or for use in jellies. More than 90 percent of all cultivated grape are varieties of V. vinifera, the old world or European grape. Originating in Anatolia, this species has been spread by humans into all temperate regions and recently into subtropical areas. At least 5,000 varieties of grape have been derived from this species.
Whereas European grapes derive exclusively from V. vinifera, native American grape come from many wild species of Vitis. These grapes are characterized by their musky, or foxy odor and flavor, and by the fact that, unlike V.vinifera, their skins slip from the fruit pulp.
Specimens of the European grape were brought by the Spanish into areas of present day California and Mexico and by the English to settlements along the Atlantic seaboard. The later plantings failed mainly because of climatic extremes; fungal diseases that thrive in the hot, humid summers, and the plants susceptibility to root aphids (Phylloxera) that are less harmful to native American grapes. Phylloxera is accidentally introduced into Europe in the mid 19th century, almost completely destroying vineyards in France, Germany, and Italy. Most wine grapes in Europe and America are grown on vines grafted onto resistant rootstocks.
Deviation of American species or hybrids of American grapes and V.vinifera are cultivated throughout the United states. They fall into three broad categories; American cultivars, the most important of which are varieties with V. labrusca as one parent, including Catawba, Niagara, and Concord grapes; the Muscadine cultivars from American V, rotundifolia; and French hybrids, crosses of V. vinifera and native American species.