Worldwide, there are more than 7,500 known varieties, 100 of which are grown commercially in the US. They all differ in shape, size, color, texture, aroma and flavor.

Broccoli florets should be tightly closed and deep green, with a purplish tinge; avoid limp or yellowing broccoli. Stems should be free of mold or signs of bruising.

Brussels sprouts are sold on and off the stalk. Look for compact heads with no sign of dulling or wilting. Sprouts should be bright green.

Red and green cabbage should have a firm, tight head and feel heavy for their size, with no black or soft spots. Savoy and Napa cabbage are generally a bit "looser".

Cardoons are sold in large bunches that look a lot like spiky, silvery celery. Stalks should be firm with no spongy or blackened spots.

Carrots come in all shades of purple, red, white, yellow and of course, orange. If they have the greens attached, look for feathery, perky leaves with no wilting, black spots or yellowing.

Look for an even color and a tightly packed head. Apart from its standard white, cauliflower also comes in purple, orange and green varieties.

Horseradish is a large and tapering root with a dark brown peel and creamy interior. Look for firm roots with no mushy or black spots.

Both the root and leafy greens of kohlrabi are edible. The bulb should be firm with no spongy bits and no visible brown spots.

There are several varieties of mushrooms and they can be purchased fresh or dried. Look for fresh mushrooms without slimy, moldy or black spots.

Parsnips are a root vegetable that look like a pale carrot, usually a shade of pale yellow or ivory. Look for parsnips that are firm but not tough.

An excellent source of both dietary fiber and Vitamin C, pears should be fragrant and soft when ripe. Unripe pears will ripen quickly in a paper bag at room temperature.

While pumpkins come in a variety of types, sizes and colors - you should always choose a pumpkin that feels heavy for its weight and pass on those with any black or mushy spots.

Quinces resemble a pear but are bumpy and round in the middle. It's common to find some nicks and bruises in its delicate skin but avoid fruit with dark brown or black mushy spots.

With its pine-like flavor, rosemary pairs well with roasted vegetables and grilled meats. Look for strong-smelling bunches and avoid withered leaves.

The rutabaga is a sweet root vegetable that looks a lot like a large turnip with pale yellow flesh. Rutabagas are often sold with a protective layer of wax that improves shelf life, so peel them before cooking.

Salsify is a slender woody root, with light brown or black skin and white flesh. White salsify is said to be similar to oysters in flavor.

Although you can sprout many seeds, the two most common sprouted types are bean and alfalfa. Look for sprouts that are perky and smell fresh. Avoid any that smell off or that appear slimy or wilted.

Sweeter and milder than their larger counterparts, baby turnips are perfect for eating raw, roasting or tossing in salads. Turnips should be firm with tight skin. Avoid any that look wrinkled or withered.

Winter squash is actually harvested in autumn before a hard frost and stored for later. Squash comes in many sizes and colors and may even have decorative warts. Avoid squash with visibly broken skin.