Dioscorea japonica, known as East Asian mountain yam, yamaimo, or Japanese mountain yam, is a type of yam (Dioscorea) native to Japan (including Ryukyu and Bonin Islands), Korea, China, Taiwan, and Assam.Kew World Checklist of Selected Plant Families
Dioscorea japonica is used for food. Jinenjo, also called the wild yam, is a related variety of Japanese yam that is used as an ingredient in soba noodles.
Names In Japanese, it is known as . is another kind of Dioscorea japonica, which is native to fields and mountains in Japan.
In Chinese, Dioscorea japonica is known as yě shānyào () which translates to English as "wild Chinese yam" or simply "wild yam". Another name is Rìběn shǔyù (; literally "Japanese yam").
In Korean, it is known as cham ma (), as well as dang ma ().
Chemistry Dioscorea japonica contains the antimutagenic compounds eudesmol and paeonol.Antimutagenic Activity of (+)-β-Eudesmol and Paeonol from Dioscorea japonica. Mitsuo Miyazawa, Hideo Shimamura, Sei-ichi Nakamura and Hiromu Kameoka, J. Agric. Food Chem., 1996, 44 (7), pages 1647–1650,
Varieties Several formal botanical varieties have been proposed. Four are accepted:
Dioscorea japonica var. japonica - Japan (Ryukyu, Bonin), Korea, Taiwan, China (Anhui, Fujian, Guangdong, Guangxi, Guizhou, Hubei, Hunan, Jiangsu, Jiangxi, Sichuan, Zhejiang) Dioscorea japonica var. nagarum Prain & Burkill - India (Assam) Dioscorea japonica var. oldhamii R.Knuth - China (Guangdong, Guangxi), Taiwan Dioscorea japonica var. pilifera C.T.Ting & M.C.Chang - China (Anhui, Fujian, Guangxi, Guizhou, Hubei, Hunan, Jiangsu, Jiangxi, Zhejiang)
Uses
In Japanese cuisine, both the Japanese yam and the introduced Chinese yam are used interchangeably in dishes and recipes.
The yam's aerial tubercles, or bulbils, called mukago, are also eaten. They are often cooked and served with white rice.
See also Tororo (food), a Japanese dish made from grating raw yams such as yamaimo
References