Yamaimo

Dioscorea japonica
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Monocots
Order:	Dioscoreales
Family:	Dioscoreaceae
Genus:	Dioscorea
Species:	D. japonica
Binomial name
Dioscorea japonica Thunb. 1784

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 (including Taiwan), and Assam.

Dioscorea japonica is used for food. Jinenjo, also called wild yam is 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 Rìběnshǔyù (literally Japanese Yam; )

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:

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Wikipedia