What's in a name? Well, for starters, sweet potatoes aren't really potatoes -- they're actually in the morning glory family. And yams are in a genus all their own, more closely related to lilies than spuds. The naming confusion can be traced to the American South in the 18th and 19th centuries, when African slaves encountered the sweet potato and naturally linked it in their minds with their native yam. But they're both delicious no matter they're called -- nomenclature aside, today we take a close look at sweet potatoes and yams.

We might as well just say it: kohlrabi is a little weird. The name literally means "cabbage turnip" in German (makes sense, right?), and they're as common as cabbages and turnips themselves in Eastern Europe, where they've been around for centuries. Stateside, though, they're a little more unusual -- "you'd think it had just landed on earth," Elizabeth Scneider says in Uncommon Fruits & Vegetables: A Commonsense Guide -- so farmers' markets and CSA boxes are your best bet for the hardy, prolific stems.

Today we're taking a nose dive into the salad bowl with a half-dozen varieties of dark leafy greens. These plants come from a few different plant families -- arugula, kale, and collards are Brassicas, spinach and chard are in the Amaranth family, and dandelion is from the family Asteraceae -- but they share certain essential characteristics in the kitchen: all can be enjoyed raw or cooked, and they're all hardier than the fragile salad greens of spring.

Celeriac -- also just called celery root -- has got to be the craggiest, least lovable plant there is. Covered in hairy roots and clods of dirt, it's like the hobbit of the vegetable world. Give it some time, though, and it'll pay you back: celeriac has all the mellow, vegetal flavor of celery and none of the stringy wateriness.