Bay leaf (Laurus nobilis) is the leaf of a large evergreen shrub or small tree grown mostly in the Mediterranean countries and Asia Minor. It is also cultivated in Greece, Portugal, Spain and Central America. The spreading branches of this evergreen are filled with smooth waxy leaves which vary in size from 1 to 3 inches long and 1/2 to 1 inch wide. They are elliptical and taper to points at the base and the tips, and the undersides of the leaves are a pale, yellowish green. The aromatic, sweet bay tree found in southern Europe is the Laurel of the Lauraceae family, and is the same plant which the Greeks call the Daphne tree. The pleasant odor of bay leaf is familiar to many and its characteristically strong, pungent, and almost bitter flavor becomes more apparent as the brittle leaf is crushed. One bay leaf, either whole or broken, will give a wonderful flavor to a can of tomato soup, and when crushed and added to tomato juice or aspic, the result is temptingly delicious. A bay leaf placed in the water in which vegetables are boiled with add a subtle interest. For example, try it in beets, onions, and potatoes. Old-fashioned vegetable soup takes on a new taste when a bay leaf is added. Bay leaves are used extensively in pickling spices and vinegars, but the amounts vary with the formula of each manufacturer who prepares them.

Source: Miloradovich, Milo (1950). Cooking with Herbs and Spices. New York: Dover; pp. 16-17.