Lemon, also known as Citrus medica, is a fragrant but inedible citrus fruit. The fruit of the citron is usually oblong and covered with an adherent leathery rind. The color of citron varies from green to yellow-orange. It differs from the rest of the citrus species, like oranges or lemons, by having a dry pulp that contains only a small amount of juice. For many centuries, citron has been used medicinally (against lung and gastrointestinal disorders) and for the production of essential oil, which not only smells great but also has antibiotic properties.