What is "chinese yam"

Yam \Yam\ (y[a^]m), n. [Pg. inhame, probably from some native name.]

1. (Bot.) A large, esculent, farinaceous tuber of various climbing plants of the genus Dioscorea; also, the plants themselves. Mostly natives of warm climates. The plants have netted-veined, petioled leaves, and pods with three broad wings. The commonest species is Dioscorea sativa, but several others are cultivated.

2. (Bot.) Any one of several cultural varieties of the sweet potato. [U. S.] Chinese yam, a plant ( Dioscorea Batatas) with a long and slender tuber, hardier than most of the other species. Wild yam.

   1. A common plant ( Dioscorea villosa) of the Eastern United States, having a hard and knotty rootstock.

   2. An orchidaceous plant ( Gastrodia sesamoides) of Australia and Tasmania.

Chinese yam (Dioscorea polystachya), also called cinnamon-vine, is a species of flowering plant in the yam family. This perennial climbing bine native to China now grows throughout East Asia ( Japan, Korea, Kuril Islands, Vietnam). It is believed to have been introduced to Japan in the 17th century or earlier. Introduced to the United States as early as the 19th century for culinary and cultural uses, it is now considered an invasive plant species. The plant was introduced to Europe in the 19th century during the European Potato Failure, where cultivation continues to this day for the Asian food market. The edible tubers, often called nagaimo or Chinese-potato, are cultivated largely in Asia and sometimes used in alternative medicine. This species of yam is unique as the tubers can be eaten raw.