Yam refers to a member of the family of Di oscorea ceae which is a staple food, ceremonial crop, and cash/export crop for Nigerians. The family is made up of 6 genera with over 600 species of which few are edible.
The species commonly grown in Nigeria are

– Dioscorea rotundata (white yam)



– Dioscorea cayenensis (Yellow yam)



– Chinese yam)



– Diocorea bulbifera(Aerial yam)
It is a monocotyledonous, predominantly dioecious and herbaceous climbing crop grown in the wet to fairly high rainfall areas with a dry season of not more than 4 to 5 months in Nigeria.



Flowering is neither regular nor consistent in the crop. For instance, flowering does not occur in D.esculente, and D.bulfibera is completely staminate. In some cases, there is no flowering at all.



The Nigerian yam belts stretch from the humid rainforest in the south to the northern Guinea savannah of Nigeria.



About 42% of yams produced in Nigeria are produced in southern Nigeria. While a larger percentage of it is produced in the middle belt or central states of Nigerian.



Namely

– Benue state



– Niger state



– And Nasarawa state.

for further reading:https://bnethub.com/yam-tubers/