page_title: Yam (vegetable)
section_title: D. polystachya
hierarchical_section_title: Yam (vegetable) / Cultivation / Major cultivated species / D. polystachya
context_page_description: Yam is the common name for some plant species in the genus Dioscorea that form edible tubers.
  Yams are perennial herbaceous vines cultivated for the consumption of their starchy tubers in many temperate and tropical regions, especially in Africa, South America and the Caribbean, Asia, and Oceania. The tubers themselves, also called "yams", come in a variety of forms owing to numerous cultivars and related species.
context_section_description: D. polystachya, Chinese yam, is native to China. The Chinese yam plant is somewhat smaller than the African, with the vines about 3 m (10 ft) long. It is tolerant to frost and can be grown in much cooler conditions than other yams. It is also grown in Korea and Japan.
  It was introduced to Europe in the 19th century, when the potato crop there was falling victim to disease, and is still grown in France for the Asian food market.
  The tubers are harvested after about 6 months of growth. Some are eaten right after harvesting and some are used as ingredients for other dishes, including noodles, and for traditional medicines.
caption: Segment of a Chinese yam (D. polystachya)
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