Terpenes are a large and diverse class of organic compounds, produced by a variety of plants, some more notable plants would be pine trees, lavender, and oranges. Terpenes are what make up the essential oil of any plant, and certain terpenes are found in many different plant essential oils. For example, Limonene is one such terpene and is found in all citrus fruits, certain types of smoking herbs, and even nutmeg. Pinene, another terpene, is found abundantly in trees like pine and fir, in smoking herbs, and in herbs like rosemary. Essential oils are used widely as natural flavor additives for food, as fragrances in perfumery, and in traditional and alternative medicines such as aromatherapy. These are the ingredients that give plants and flowers their distinctive odors.