Dioscorea japonica

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. 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. In Japanese, it is known as yamaimo (山芋) 'mountain yam'. Jinenjo (自然薯) 'wild yam' is another kind of Dioscorea japonica, which is native to fields and mountains in Japan. In Chinese it is known as Yěshān yào (野山药) which translates to English as wild mountain medicine. Another name is Rìběnshǔyù (literally Japanese Yam; 日本薯蓣) In Korean it is known as cham ma 참마, as well as dang ma 당마. Dioscorea japonica contains the antimutagenic compounds eudesmol and paeonol. Several formal botanical varieties have been proposed. Four are accepted: