The lemon is both a small evergreen tree (Citrus × limon, often given as C. limon) native to Asia, and the tree's oval yellow fruit. The fruit is used for culinary and nonculinary purposes throughout the world – primarily for its juice, though the pulp and rind (zest) are also used, mainly in cooking and baking. Lemon juice is about 5% to 6% (approximately 0.3 M) citric acid, which gives lemons a sour taste, and a pH of 2 to 3. This makes lemon juice an inexpensive, readily available acid for use in educational science experiments. Many lemon-flavored drinks and candies are available, including lemonade and sherbet lemons. The distinctive sour taste of lemon juice makes it a key ingredient in many dishes across the world.