''Dioscorea japonica'', known as East Asian mountain yam, yamaimo, or Japanese mountain yam, is a type of yam (''

Dioscorea ''Dioscorea'' is a genus of over 600 species of flowering plants in the family Dioscoreaceae, native throughout the tropical and warm temperate regions of the world. The vast majority of the species are tropical, with only a few species extendi ...

'') native to

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the n ...

(including

Ryukyu The , also known as the or the , are a chain of Japanese islands that stretch southwest from Kyushu to Taiwan: the Ōsumi, Tokara, Amami, Okinawa, and Sakishima Islands (further divided into the Miyako and Yaeyama Islands), with Yonagu ...

and

Bonin Islands The Bonin Islands, also known as the , are an archipelago of over 30 subtropical and tropical islands, some directly south of Tokyo, Japan and northwest of Guam. The name "Bonin Islands" comes from the Japanese word ''bunin'' (an archaic rea ...

Korea Korea ( ko, 한국, or , ) is a peninsular region in East Asia. Since 1945, it has been divided at or near the 38th parallel, with North Korea (Democratic People's Republic of Korea) comprising its northern half and South Korea (Republic ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's List of countries and dependencies by population, most populous country, with a Population of China, population exceeding 1.4 billion, slig ...

Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia, at the junction of the East and South China Seas in the northwestern Pacific Ocean, with the People's Republic of China (PRC) to the northwest, Japan to the no ...

, and

Assam Assam (; ) is a state in northeastern India, south of the eastern Himalayas along the Brahmaputra and Barak River valleys. Assam covers an area of . The state is bordered by Bhutan and Arunachal Pradesh to the north; Nagaland and Manipur ...

.Kew World Checklist of Selected Plant Families
/ref> ''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 Soba ( or , "buckwheat") is a thin Japanese noodle made from buckwheat. The noodles are served either chilled with a dipping sauce, or hot in a noodle soup. The variety ''Nagano soba'' includes wheat flour. In Japan, soba noodles can be found ...

'' noodles. Mugitoro gohan 1

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 ''Dioscorea polystachya'' or Chinese yam ( zh, s=山药, t=山藥), also called cinnamon-vine, is a species of flowering plant in the yam family. It is sometimes called Chinese potato or by its Korean name ''ma''. It is a perennial climbing vin ...

" 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 Antimutagens are the agents that interfere with the mutagenicity of a substance. The interference can be in the form of prevention of the transformation of a promutagenic compound into actual active mutagen, inactivation, or otherwise the preventio ...

compounds eudesmol and

paeonol Paeonol is a phenolic compound found in peonies such as ''Paeonia suffruticosa'' (moutan cortex), in '' Arisaema erubescens'', and in '' Dioscorea japonica''. It is a chemical compound found in some traditional Chinese medicines. Biological eff ...

.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

are used interchangeably in dishes and recipes.

References

{{Authority control japonica Root vegetables Flora of China Flora of Eastern Asia Flora of Assam (region) Plants described in 1784