Lavender is an evergreen small shrub with linear or lance-shaped leaves original to the Mediterranean region. With approximately 30 species around the world, "Lavandula" comes from "lavare" which means "to wash" in Latin. Dioscorides, Greek military physician (40-90AD) first mentioned the plant's healing qualities, advising using it as a tea with laxative and invigorating properties. Galen, Imperial Roman physician (130-200AD), included lavender as antidote for poisons and bites. In the Middle Ages, decoctions of lavender were recommended for pulmonary congestion, dizziness, and headaches. A bath steeped in lavender was also recommended to promote rest and sleep. It was considered a mild sedative used to treat nervousness, insomnia, and headaches; also a great digestive aid to treat nausea or the feeling of being too full.