Herbs and spices are ingredients that we use to add flavor to foods and drinks. Herbs are plant leaves, fresh or dried, and spices are bits of dry seed, bark, and root. We consume them in tiny amounts, and they have practically no nutritional value. Yet from earliest times, these aromatic bits have been among the most highly prized and costly of all ingredients. In the ancient world they were more than mere foods: they were thought to have medicinal and even transcendental properties. Sacrificial fires wafted the fumes of aromatics upward to please the gods, and at the same time offered earth-bound humans a whiff of heaven. Spices came from the ends of the earth, from Arabia and legendary lands to the east. The growing hunger for the aromas of paradise helped drive the European exploration of the globe, the discovery of the Americas, and the biological and cultural exchange that helped shape the modern world.