Yam (vegetable) Yam (vegetable) Yam is the common name for some plant species in the genus "Dioscorea" (family Dioscoreaceae) that form edible tubers. Yams are perennial herbaceous vines cultivated for the consumption of their starchy tubers in many temperate and tropical world regions. The tubers themselves are also called "yams", having numerous cultivars and related species. In parts of the United States and Canada, "yam" is sometimes used to refer to varieties of the unrelated sweet potato ("Ipomoea batatas"). The name, yam, appears to derive from Portuguese "inhame" or Canarian (Spain) "ñame", which derived from West African languages during trade. The main
History of manifolds and varieties History of manifolds and varieties The study of manifolds combines many important areas of mathematics: it generalizes concepts such as curves and surfaces as well as ideas from linear algebra and topology. Certain special classes of manifolds also have additional algebraic structure; they may behave like groups, for instance. In that case, they are called Lie Groups. Alternatively, they may be described by polynomial equations, in which case they are called algebraic varieties, and if they additionally carry a group structure, they are called algebraic groups. The term "manifold" comes from German "Mannigfaltigkeit," by Riemann. In English, "manifold" refers to