One question people ask me all the time is what is the difference between yams and sweet potatoes. I think this is a great question too so I did a little research and this is what I came up with as an answer for you.
The similarity is that they are both tubers or fleshy root but they are not related at all. The confusion apparently started during slavery times when there were two main varieties of sweet potatoes. In order to differentiate between the two types slaves started calling the softer type “yams” because they were the most similar to yams found in Africa. The mis-labeling has continued to today. Here are some basic differences.
Yams are primarily grown in tropical climates predominantly in South America, Africa, and the Caribbean. Scientifically, Yams are considered monocot plants that come from one seed leaf and are part of the Dioscoreaceae or yam family. Yams are starchier than sweet potatoes so they appear to have a sweeter taste. They are also drier than sweet potatoes. Yams have a brown or black skin on the outside and inside have purple, red or off-white.
Sweet potatoes are dicots. They come from two seed leaves and are part of the Convolvulacea or morning glory family. Sweet potatoes are elongated with ends that come to a point. The outer skin can range from white to yellow, red, purple or brown in color. The inside flesh can also range from white to yellow, orange, orange-red or purple in color. The most common colors are usually orange or creamy white. Sweet potatoes have large amounts of beta- carotene. Beta carotene is the pre-cursor to vitamin A which is important for the repair of all cells in the body. Sweet potatoes are high in antioxidants which protect cells from being damaged. Sweet potatoes have anti-inflammatory properties and help to reduce chemicals that cause inflammation in the body. Even though sweet potatoes are starchy they have been shown to help balance blood sugar levels! They help release a protein that helps with insulin release. They are a good source of fiber along with the vitamins and nutrients.