Are sweet potatoes and yams the same thing?


Are sweet potatoes and yams the same thing?


In the United States, sweet potatoes are often referred to as “yams.”  However, sweet potatoes and yams are different crops. 

Sweet potatoes (Ipomoea batatas) are vining plants in the morning glory family.  They are believed to be native to Central and South America.  The storage roots of sweet potatoes are short, blocky, with tapered ends.  They have a smooth, thin skin.  There are two main types of sweet potato.  Dry-fleshed types usually have a light yellow skin and pale yellow flesh.  When cooked, they are dry and crumbly, much like a baking potato.  Moist-fleshed types typically have a dark orange skin, orange flesh, and are moist and sweet when cooked.  In the United States, the moist, orange-fleshed types are the most commonly grown sweet potato and are often referred to as “yams.” 

True yams (Dioscorea batatas) are vining plants in the yam family.  They are native to Africa and Asia.  Yams are long, cylindrical, underground tubers with a rough, scaly skin.  Tubers can be several feet long and weigh 50 pounds or more.  Yams are rarely found in the United States.  However, they are popular in Latin American countries. 

The word “yam” comes from the African word “nyami” (meaning “to eat”) for true yams.  It is believed that black Africans brought to America during the slave trade began referring to sweet potatoes as “yams” because of their similarity to true yams.