"Jicama (HEE-kuh-muh), a rounded tuber indigenous to Central America, has a thin, light brown skin and mild, crisp, juicy white flesh. It's also known as a "yam bean" because it is the bulbous root of a leguminous plant."
That's the Moosewood cookbook definition. But "yam bean"??? That doesn't sound tasty at all!
It is light brown and looks like a big turnip or potato. It has very little flavor of it's own, but provides crispy juiciness--kind of like an apple.