He aʻa ʻai ʻo Yams a i ʻole ʻuala, e like me ka ʻuala. Ke ulu nei ka ʻuala ma nā ʻāina ʻāina. Nui ka poʻe e ʻai i ka ʻuala no ka hapa nui o kā lākou ʻai. Hoʻohana ʻia nā ʻano ʻuala ʻē aʻe ma ke ʻano he lāʻau lapaʻau.
Ma ka biology, he ʻano mea kanu ka ʻuala, aia ma kahi o 800 mau ʻano ʻano like ʻole. Ma luna o ka lepo, ulu nui ia i nā mea kanu a makemake hoʻi e makani iā ia iho ma luna o nā mea kanu ʻē aʻe. I loko o ka lepo, lālā nā aʻa a hana i nā aʻa tuberous hiki ke ʻai ʻia. ʻO ia ke kumu e ʻōlelo pinepine ai kekahi i ke kumu ubi.
Hiki i nā nodule aʻa o kekahi ʻano ke ulu a hiki i ʻelua mika ka lōʻihi. Eia nō naʻe, mahi ʻia nā ʻano me nā ʻuala pōkole. Ma mua o ka ʻai ʻana, pono ʻoe e kuke iā lākou. Aia ko lākou ʻono ma waena o ka ʻuala a me ka chestnut. ʻO ka ʻuala nō hoʻi ka meaʻai e like me kēia mau mea ʻelua. Loaʻa i ka nui o nā carbohydrates. He ikaika kēia e hāʻawi i ko mākou mau ʻiʻo i ka mana.
Hoʻoulu ʻia ka hapa nui o nā ʻuala ma ʻApelika. Aia ma luna o Nigeria. Ma kahi o 250 kilokani ʻuala e ʻohi ʻia i kēlā me kēia makahiki i kēlā me kēia kanaka. A laila hele mai ʻo Ghana, Ivory Coast, Benin, a me kekahi mau ʻāina ʻē aʻe. ʻO kahi ʻāina ma waho o ʻApelika e hahai wale ana ma kahi ʻumi, ʻo ia hoʻi ʻo Haiti.