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
Varieties of Chinese increase, although there are also some sharp boundaries. However, the rate of change in mutual intelligibility varies immensely depending on region. For example, the varieties of Mandarin spoken in all three northeastern Chinese provinces are mutually intelligible, but in the province of Fujian, where Min varieties predominate, the speech of neighbouring counties or even villages may be mutually unintelligible. Classifications of Chinese varieties in the late 19th century and early 20th century were based on impressionistic criteria. They often followed river systems, which were historically the main routes of migration and communication in southern China. The first scientific classifications, based