beet, biennial or annual root vegetable of the family Chenopodiaceae (goosefoot family). The beet ( Beta vulgaris ) has been cultivated since pre-Christian times. Among its numerous varieties are the red, or garden, beet, the sugar beet, Swiss chard, and several types of mangel-wurzel and other stock feeds. Both the roots and the foliage of the red beet are edible, as is the foliage of Swiss chard and similar varieties. The easily stored roots of the mangel-wurzel [Ger., = beet root] are much used for fodder in Europe and Canada and to a lesser extent in the United States. The biennial beet is often used in crop rotation. The foliage of the sugar beet and several other varieties is also used as feed. The sugar beet, cultivated commercially throughout the temperate zone, to which it is well adapted, provides about one third of the world's commercial sugar production; virtually all the rest comes from sugarcane. In the United States, sugar beets are grown extensively from Michigan to Idaho and in California, accounting for more than half of United States sugar production. Since the 18th cent. selective breeding has raised the root's sucrose content from 2% or 4% to 15% and even 20%. The extracted beet sucrose, dissolved in water, is refined and granulated, much like cane juice, to make sugar. Beets are classified in the division Magnoliophyta, class Magnoliopsida, order Caryophyllales, family Chenopodiaceae.