The lemon (Citrus × limon) is a species of small evergreen tree in the flowering plant family Rutaceae, native to Asia, primarily northeastern India (Assam), northern Myanmar, and China. The tree's ellipsoidal yellow fruit is used for culinary and non-culinary purposes throughout the world, primarily for its juice, which has both culinary and cleaning uses. The pulp and rind are also used in cooking and baking. The distinctive sour taste of lemon juice, derived from citric acid, makes it a key ingredient in drinks and foods. This photograph shows a whole and halved lemon against a black background.Photograph credit: Ivar Leidus