The "lemon" (Citrus x limon) is a small, evergreen tree in the Rutaceae family. A hybrid of the citron and bitter orange, it is believed to have originated in northeastern India. The yellow fruit is primarily valued for its juice, which contains 5-6% citric acid, giving it a sour taste. The juice, pulp, and rind are widely used in cooking, baking, and beverages like lemonade.