Ask anybody south of the Mason-Dixon line to talk about side dishes and yams always come up. This variation on the usual theme brings together two of the King’s favorites.
Yam is the common name for some plant species in the genus Dioscorea (family Dioscoreaceae) that form edible tubers.
These are perennial herbaceous vines cultivated for the consumption of their starchy tubers in Africa, Asia, Latin America, the Caribbean and Oceania. There are many cultivars of yam. Although some varieties of sweet potato (Ipomoea batatas) are also called yam in parts of the United States and Canada, sweet potato is not part of the family Dioscoreaceae but belongs in the unrelated morning glory family Convolvulaceae.
Yams are monocots, related to lilies and grasses. Native to Africa and Asia, yam tubers vary in size from that of a small potato to over 60 kg (130 lb). There are over 600 varieties of yams and 95 percent of these crops are grown in Africa.
The differences between true yam and sweet potato “yam”
Yams are a monocot (a plant having one embryonic seed leaf) and from the Dioscoreaceae family. Sweet Potatoes are a dicot (a plant having two embryonic seed leaves) and are from the Convolvulaceae family. Therefore, they are about as distantly related as two flowering plants can be. Culinarily, yams are starchier and drier than sweet potatoes. The table below lists some differences between yam and sweet potato.