The lemon is a small evergreen tree native to Asia, and the trees ellipsoidal yellow fruit. The fruit is used for culinary and non-culinary purposes throughout the world, primarily for its juice, though the pulp and rind are also used in cooking and baking. The juice of the lemon is about 5% to 6% citric acid, which gives lemons a sour taste. The distinctive sour taste of lemon juice makes it a key ingredient in drinks and foods such as lemonade.