Difference Between Yams And Sweet Potatoes
Yam, the common name for plants of the genus Dioscorea of the family Dioscoreaceae (called the yam family), or for their tubers. In the United States certain varieties of sweet potato are incorrectly called yams. True yams, of which about 600 species are known, are found throughout tropical and warm temperate regions. Four species are native to the United States.
Yams are herbaceous vines whose stems twine consistently to the right or left, depending on the species. They have usually heart-shaped, prominently veined leaves; clustered small green, white, or yellow flowers; and three-angled capsules containing winged flat seeds. Yams are among the most important tropical root crops, some kinds being baked, boiled, or fried, some used for soup, and some dried and ground into meal.
Sweet Potato, a creeping perennial plant cultivated for its fleshy underground roots. Probably native to tropical America, it was introduced into Spain from the West Indies in 1526. It was then disseminated to other parts of Europe and is believed to have been first grown in the United States in 1648.
The sweet potato has prostrate stems containing a milky, latexlike sap. Its leaves may be rounded, heart-shaped, or lobed and are often 2 to 6 inches (5–15 cm) long. The pink or violet flowers are about 2 inches long and resemble those of the morning glory. The tuberous roots are usually several inches long, and their flesh may be white, yellow, or orange. The varieties used for food are classified into soft fleshed and hard fleshed. The former are sweeter and softer when cooked. The nonfood varieties are used for flour, livestock feed, and several chemical processes.
Sweet potatoes are susceptible to injury by frost and require a long, warm growing season. Although they are more drought resistant than most other vegetables, they are generally grown in regions where the annual rainfall is 40 inches (100 cm) or more. In the United States the leading producers are Louisiana, North Carolina, Texas, and Virginia.