African blue basil (Ocimum kilimandscharicum × basilicum 'Dark Opal') is a hybrid basil variety, a cross between camphor basil and dark opal basil. It is one of a few types of basil that are perennial. African blue basil plants are sterile, unable to produce seeds of their own, and can only be propagated by cuttings. All parts of the flower, leaves and stems are edible; although some might find the camphor scent too strong for use in the kitchen, the herb reportedly yields a tasty pesto with a "rich, mellow flavor" and can be used as a seasoning in soups and salads, particularly those featuring tomato, green beans, chicken, etc.[1] The leaves of African blue basil start out purple when young, only growing green as the given leaf grows to its full size, and even then retaining purple veins.