The lemon, Citrus limon, is a species of small
evergreen tree in the flowering plant family
Rutaceae, native to South Asia.
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
juice of the lemon is about
5% to 6% citric acid, with a pH of around 2.2, giving
it a sour taste. The distinctive sour taste of lemon
juice makes it a key
ingredient in drinks and foods such as lemonade and
lemon meringue pie.