The origin of lemon is unknown but believed to be originated in Asia.
Lemon is a small evergreen tree which can grow to 6m tall. The tree has stout spines. The leaves are dark green, leathery, and evergreen, oblong, elliptical, or oval and up to 14 cm long. Flower buds are purplish but flowers open to have 4 to 5 white petals, up to 5 cm across. The flowers are fragrant and borne singly or in clusters of 2 to 10 in the leaf axils. The prominent stamens are white with orange anthers.
Fruits are globose to oblong, 7.5 to 12.5 cm long, and ripen to yellow, with smooth to bumpy rinds dotted with oil glands. The fruit is used for culinary and non-culinary purposes throughout the world, primarily for its juice, though the pulp and rind (zest) 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.