The things in stores labeled 'yams' are not true yams. They are actually one of two species of sweet potatos. True yams have blackish skins and purpleish insides. So in US stores there is no real difference at all. Some people may grow true yams in gardens but ive never seen one. True yams and sweet potatos are not related at all. The only similarity is that both are starchy tubers.
9 months ago
Last edited at 3:08PM on 6/15/2013
Sweet potatoes are yellow or orange tubers, elongated with ends that taper to a point, and are popular in the American South. Yams are tubers of a tropical vine, with brown or black skin and off-white, purple or red flesh. They grow in tropical climates. Although yams and sweet potatoes are both angiosperms (flowering plants), they are not related botanically. Yams are a monocot (a plant having one embryonic seed leaf) and from the Dioscoreaceae or Yam family. Sweet Potatoes, often called ‘yams’, are a dicot (a plant having two embryonic seed leaves) and are from the Convolvulaceae or morning glory family.
9 months ago
Last edited at 12:14AM on 6/16/2013
I have read the other responses and I can tell none of them were written by a southerner. I am a southerner and trust me we know there is a big difference. The other people who have answered have apparently never used either and have eaten encyclopedias instead. (They probably think that there is no difference in the tea blends for hot and cold teas! as well) A yam is a tuber with a loose tough leathery outer skin and its meat is stringy. What you get in a can is a yam. Sweet Potatoes are potatoes with a smooth orange-yellow color meat, like a potato. You cannot make sweet potato fries or whipped sweet potatoes with yams.