Botanical medicine, in simplistic terms, is the use of plants as medicines. Plants hold a power healing capacity, and before conventional medicine was invented, botanical remedies were the basis of health care. In fact, some pharmaceutical drugs are synthetic components that were found in plants, such as the active constituent in Aspirin, acetylsalicylic acid, being a prodrug of salicylic acid found in willow bark. All parts of plants can be used, including leaves, flowers, stems, roots or seeds. Administering botanical medicine can also take many forms; including teas, tinctures, capsules, ointments, creams or essential oils.