Dioscorea cayenensis subsp. rotundata

Dioscorea cayenensis subsp. rotundata, commonly known as the white yam, West African yam,^[1] Guinea yam, or white ñame, is a subspecies^[2] of yam native to Africa. It is one of the most important cultivated yams.^[3] Kokoro is one of its most important cultivars.

Dioscorea cayenensis subsp. rotundata
White yam
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Monocots
Order:	Dioscoreales
Family:	Dioscoreaceae
Genus:	Dioscorea
Species:	D. cayenensis
Subspecies:	D. c. subsp. rotundata
Trinomial name
Dioscorea cayenensis subsp. rotundata (Poir.) J.Miège

It is sometimes treated as separate species from Dioscorea cayenensis.^[1]

Domestication

Its wild progenitor is Dioscorea praehensilis^[1] and possibly also D. abyssinica (by hybridization).^[4] Domestication occurred in West Africa, along the south-facing Atlantic coast. There is insufficient documentation and as of 2009^[update] insufficient research to determine how long ago that occurred.^[5]

Distribution

D. c. subsp. rotundata is grown in West Africa, including countries such as Ivory Coast, Ghana and Nigeria.^[6]

Linguistics

Blench (2006) reconstructs the tentative Proto-Niger-Congo (i.e., the most recent common ancestor of the Niger-Congo languages) root -ku for D. rotundata.^[1]