Called the "royal herb" by ancient Greeks, this annual is a member of the mint family. Fresh basil has a pungent flavor that some describe as a cross between licorice and cloves. It's a key herb in Mediterranean cooking, essential to the delicious Italian pesto, and is becoming more and more popular in American cuisine. Most varieties of basil have green leaves, but one — opal basil — is a beautiful purple color. Lemon basil and cinnamon basil have green leaves but their perfumy fragrance and flavor matches their respective names. Basil is a summer herb but can be grown successfully inside during the winter in a sunny window. It's plentiful during summer months, and available year-round in many markets. Choose evenly colored leaves with no sign of wilting. Refrigerate basil, wrapped in barely damp paper towels and then in a plastic bag, for up to 4 days. Or store a bunch of basil, stems down, in a glass of water with a plastic bag over the leaves. Refrigerate in this manner for up to a week, changing the water every 2 days. To preserve fresh basil, wash and dry the leaves and place layers of leaves, then coarse salt, in a container that can be tightly sealed. Alternatively, finely chop the cleaned basil and combine it with a small amount of olive oil. Freeze in tiny portions to flavor sauces, salad dressings, etc. Dried basil, though it bears little resemblance in either flavor or aroma to the fresh herb, can be purchased in the spice section of most supermarkets. Store dried basil airtight in a cool, dark place for up to 6 months. See also herbs; field guide to herbs; herb and spice chart.