grape sugar: see glucose.

grape hyacinth, any plant of the genus Muscari of the family Liliaceae (lily family), low plants with dense spikelike clusters of small, nodding flowers that are usually deep blue. Of more than 50 Old World species several have been successfully cultivated and naturalized in the United States and are especially popular as rock-garden plants. Grape hyacinths are classified in the division Magnoliophyta, class Liliopsida, order Liliales, family Liliaceae.

grape, common name for the Vitaceae, a family of mostly climbing shrubs, widespread in tropical and subtropical regions and extending into the temperate zones. The woody vines, or lianas, climb by means of tendrils, which botanically are adaptations of terminal buds. The principal genera are Cissus, chiefly tropical, Parthenocissus (including the Virginia creeper and Boston ivy), Ampelopsis (see ampelopsis), and Vitis; the latter three include species native to the United States. Plants of the grape genus Vitis are extensively cultivated throughout the Northern Hemisphere. V. vinifera, which probably originated in the Mediterranean area and W Asia, is the grape of agriculture known since ancient times and frequently mentioned in the Bible. It is cultivated in the Old World and has been introduced successfully in South America and on the west coast of North America. Attempts to naturalize it E of the Rockies failed, chiefly because of the insect pest phylloxera; the grapes now grown in this area are either hybrids of V. vinifera with resistant American grapes or varieties derived from native American species. Chief among these are V. rotundifolia, the muscadine, or scuppernong, grape, and its varieties (James, Eden, and others) of the Gulf and southeastern states, and V. labrusca, the fox grape, from which are derived the Concord, Catawba, Delaware, and many other cultivated varieties of the eastern and northern states. California produces some two thirds of the grapes grown in the United States, and New York state ranks second in output. Grapes are sometimes classed according to their use, e.g., wine, raisin, table, juice, or canning grapes. The cultivated grapevine is prey to numerous pests and diseases and requires a great deal of care (see vineyard). The art of grape growing was said in Greek legend to have been introduced by Dionysus; Bacchus was the god of wine. Throughout history, the grape has been a symbol in art and literature of revelry and joy. Grapes are classified in the division Magnoliophyta, class Magnoliopsida, order Rhamnales, family Vitaceae.

Oregon grape: see barberry.

Any of the approximately 50 species of small bulbous perennial plants that make up the genus Muscari, in the lily family, native to the Mediterranean region. Most species have dense clusters of blue, white, or pink urn-shaped flowers borne at the tip of a leafless flower stalk. Some species have a musky odour. Grape hyacinths often are planted as spring-flowering garden ornamentals.

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or dextrose or grape sugar or corn sugar

Organic compound, a simple sugar (monosaccharide), chemical formula C₆H₁₂O₆. The product of photosynthesis in plants, it is found in fruits and honey. As the major circulating free sugar in blood, it is the source of energy in cell function and a major participant in metabolism. Control of its level and metabolism is of great importance (see insulin). Glucose and fructose make up sucrose. Glucose units in long chains make up polysaccharides (e.g., cellulose, glycogen, starch). Glucose is used in foods, medicine, brewing, and wine making and as the source of various other organic chemicals.

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Small, greenish yellow insect (Phylloxera vitifoliae, order Homoptera) that is highly destructive to grape plants in Europe and the western U.S. It sucks fluid from grapevines, causing galls to form on leaves and nodules on roots; eventually the plants rot. It was introduced into Europe from the eastern U.S. in the mid-19th century and within 25 years had almost destroyed the grape and wine industries in France, Italy, and Germany. Vines were saved by grafting European plants to rootstocks of resistant vines native to the U.S. Hybrids and fumigants are used to combat the pest.

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Any of the 60 plant species that make up the genus Vitis (family Vitaceae), native to the northern temperate zone, including varieties that may be eaten as table fruit, dried to produce raisins, or crushed to make grape juice or wine. V. vinifera is the species most commonly used in wine making. The grape is usually a woody vine, climbing by means of tendrils. In arid regions it may form an almost erect shrub. Botanically, the fruit is a berry. Grapes contain such minerals as calcium and phosphorus and are a source of vitamin A. All grapes contain sugar (glucose and fructose) in varying quantities depending on the variety.

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