Clockwise from top left: Sweet basil, Thai basil, holy basil, dark opal basil

Long a staple in Italian kitch­ens—where it’s often paired with tomatoes or pureed into pesto—basil also flavors the cooking pots of France, Greece, Thailand, the West Indies, and the Middle East. Of course, American chefs have also embraced this versatile herb.

There are more than 150 species of basil classified in the genus Ocimum, but the type widely used for culinary purposes is Ocimum basilicus. The most common variety cultivated is sweet basil or large leaf basil—a plant with oval-shaped leaves ranging in size from 1-2 in., and varying in color from light to deep green, burgundy red, or some combination of all three. Sweet basil may start off smelling like cloves with a strong minty component, then hints of anise, cinnamon, citrus, and camphor may be revealed.

Other varieties in the Ocimum basilicus species include the tiny-leafed bush basil, called Nano verde (green dwarf) by Italian horticulturists; lemon basil (with small, pointed, fuzzy leaves); cinnamon basil (with a distinct cinnamon taste); and purple basil (see box). But there are several lesser-known kinds that may not be as familiar:

Holy basil has purple-tinged leaves and a pungent, camphor -like taste. Regarded by the Hindus as sacred, it’s not used much in Indian cooking, but is found more often in Southeast Asian dishes.

Tree basil, or East Indian basil, is a shrubby species with green leaves. West Africans use it in savory dishes and salads.

Thai basil, or Sweet Asian basil, is milder than holy basil, with a pleasant anise or licorice note.

Basil is often referred to as “the king of herbs”—in Greek, basilicus means king—and it’s easy to see why. Its multi-faceted flavor does not overpower food and marries well with many ingredients. For a gentle accent, season frittatas, fish, or chicken with a scattering of chopp­ed leaves, or combine liberal amounts of basil with chiles, ginger, and citrus to pump up the flavor of Asian dishes. Add whole leaves to pizzas, sandwiches, and salads, or sprinkle chiffonade (thin strips) over soup or pasta. Try the herb in desserts, too; its clove and mint undertones partner well with summer fruits. Or steep basil sprigs in milk or cream to make a custard base for a sauce or ice cream.

Fresh basil should have a strong aroma and soft, green, unbruised leaves. The herb can be tricky to store—it wilts if too warm, and turns black if too cold. If you plan to use it within a day or two, stand the bunch, stems down, in a jar of water on the counter. To store for up to a week, trim the stems, rinse and gently dry the leaves, then layer loosely between paper towels enclosed in a heavy plastic bag, and refrigerate.

For longer storage,whip up a batch of pesto (or pistou, as it’s known in French kitchens). It will keep for a month in the refrigerator and up to six months in the freezer. Dried basil bears little resemblance to the fresh, but it can be used successfully in tomato sauces, stews, rubs, and marinades.

Purple passion
Green basil has long been popular in the kitchen, but lately, beautiful purple varieties have become more widely available.

Purple ruffle basil has large, crinkly, deep red leaves with frilly edges. The taste is similar to sweet green basil and it can be substituted for its more familiar cousin in salads and cold dishes; the leaves turn dark green when exposed to heat.

Dark opal basil has smooth leaves, about an inch long, with slightly jagged edges. Its gingery flavor works well in stir-fries, fruit preparations, and desserts.