Dioscorea rotundataandandandD cayenensis

Dioscorea rotundata, the andwhite yamand, andandDioscorea cayenensis, the andyellow yamand, are native to Africa. They are the most important cultivated yams. In the past they were considered two separate species but most taxonomists now regard them as the same species. There are over 200 cultivated varieties between them. White yamands tuber is roughly cylindrical in shape, the skin is smooth and brown and the flesh usually white and firm. Yellow yam is named after its yellow flesh, a color caused by the presence of carotenoids.