Lemon

Small evergreen trees, up to 6 m. Numerous axillary spines, 5-27 mm. Leaves elliptic to oval, 4-12 cm long, 2-6 cm wide. Fruits edible, acid (pH 2.2), 5-10 cm, light yellow (lemon fruit).

Native to Northeastern India, Northern Burma and Southern China. Introduced to the New World by Columbus in 1498, today widespread in the tropics and subtropics.

The juice of the lemon is about 5% to 6% citric acid, which gives the sour taste. Before the development of fermentation-based processes, lemons were the primary commercial source of citric acid.