Today's "What in the world is" is called "Jicama" which is pronounced, "He-Ka-Ma" (you're welcome!)
It's a vegetable I didn't know existed until my cousins from Phoenix, AZ told me about it.
According to wisegeek.com:
Jicama is a crispy, sweet, edible root that resembles a turnip in physical appearance, although the plants are not related. Jicama has been cultivated in South America for centuries, and the vegetable is quite popular in Mexican cuisine. Jicama has a unique flavor that lends itself well to salads, salsas, and vegetable platters. The roots can sometimes grow to be quite large, although when they exceed the size of two fists, they begin to convert the sugars that give jicama its sweet flavor into starches, making the root somewhat woody to the taste.
Jicama is actually a legume, and it grows on vines that may reach 20 feet (six meters) in length. The vines tend to hug the ground, terminating in tubers that may grow up to 50 pounds (22 kilograms) in size, although the majority of jicama roots sent to market are approximately three to four pounds (1.3-2 kilograms) in weight. Before eating, the coarse brown outer layer of the jicama should be peeled to reveal the white inside.
When choosing jicama at the store, look for medium sized, firm tubers with dry roots. Do not purchase jicama that has wet or soft spots, which may indicate rot, and don't be drawn to overlarge examples of the tuber, because they may not be as flavorful. Jicama will keep under refrigeration for up to two weeks.I like to add it to salads, especially something with beans and corn. Amazing that it's a legume! WHO KNEW? Judging by my excitement, I'm a total nerd :)