Is a yam the same as a potato?
Potatoes and Yams are quite different from one another. While both are edible tubers, they are markedly different in texture, flavour and cooking times. To confuse the subject further, the word yam is used to refer quite different families of tubers. In most of the world, Yam is the common name for group of tubers native to Africa and Asia. In the southern parts of the United States the word is used to refer to a group of tubers native to South America - which are called sweet potatoes elsewhere.
Yam, and sweet potato are like a potato, except they are sweet. With yam being sweeter than the sweet potato, they are not the same plant despite popular belief. Also a vegetable called celery root, or celariac can apparently be made to taste like mashed potatoes. Yam and sweet potato are root tubers Celariac is a root vegetable
It depends which plant is used for the starch. Some of the names are simply based on the name of the plant. Some major examples are: Cassava (or Manioc): Tapioca, Farinha, Gari. Potato: Potato Starch. Sweet Potato: Sweet Potato Starch. Taro: Poi. Yam (not the same plant as Sweet Potato): Yam Starch. Arrowroot starch is made from a variety of different plants.