It has been considered at various times to be either sacred or evil, and in 1597 John Gerard in his Herball or Generall Historie of Plantes warned against using it internally. In modern times, basil is best known for its wonderful flavor, and adds flavor to meat, seafood, pasta, soups, egg and salad recipes. Of course it is best known as the main ingredient in pesto sauce, developed in Italy, where the nuances of pesto-making are a matter of regional pride and tradition. Basil has anti-microbial properties and is an ingredient in some perfumes, mouthwashes and natural insecticides. Basil hybridizes easily and often, creating a wide variety of leaf colors, textures, sizes and fragrances.
Leaves can be small or large, smooth or hairy, ruffled or plain, green, purple or a little of both.
The flowers are borne on terminal spikes and are white or shades of pink. Large-leaved green basils, sometimes called lettuce leaf basil, can grow two or three feet in height, and just as broad if well pinched. Reddish-purple cultivars such as 'Dark Opal' or 'Purple Ruffles' tend to be intermediate in size, bearing pink instead of white flowers. The purple basils have minor nuances of flavor and are used for the same purposes. Novelty basils have some culinary uses and are worth taste testing for individual preferences.