The plant family Dioscoreaceae was named and described by Robert Brown in Prodromus Systematis Naturalis Regni Vegetabilis in 1810.
Plants of the World Online lists four genera in the family Dioscoreaceae. They include Dioscorea, Stenomeris, Tacca, and Trichopus. My experience is with Tacca chantrieri (Black Bat Flower) and Tacca integrifolia (White Bat Flower).
Wikipedia states the best-known member of this family is the yam and is commonly referred to as the yam family. In the US, we consider the yam to be a sweet potato, which is actually the species Ipomoea batatas which is a member of the plant family Convolvulaceae.
In this family, the genus Dioscorea “included” two species that are well known for their production of edible tubers, Dioscorea cayenensis and Dioscorea rotundata. Dioscorea cayenensis produced the yellow yam and Dioscorea rotundata produced white yams. Now, Dioscorea rotundata is a synonym of Dioscorea cayenensis. Oh yeah, I almost forgot to mention there are 623 accepted species in the Dioscorea genus listed in Plants of the World Online. Members of this genus are native of many countries but Dioscorea cayenensis is native to parts of Africa.
As I already mentioned, Plants of the World Online lists 623 species of Dioscorea. It also lists 2 species of Stenomeris, 17 species of Tacca, and 2 species of Trichopus. Those are the numbers as of 2-24-21 when I last updated this page.
For more information about this family of plants, please click on the links below. The links take you directly to the information about the family.