The most common variety for pesto, basil genovese is what's known as a sweet basil (Ocimum basilicum), prized for its delicate fragrance, which doesn't overpower the other ingredients in the sauce. Todd Coleman

A relative of mint, basil thrives in hot, dry climates. Though it is predominantly associated with Mediterranean cuisines, the herb is native to India and used the world over in fresh and cooked preparations. There are more than 40 culinary basil varieties ranging in flavor from delicately herbaceous to downright emphatic, and we had fun experimenting with them to take our pestos in different directions.

See eight varieties of basil in the photo gallery »