The lemon is an evergreen tree which bears a fruit of the same name. Lemon trees are thought to have first appeared in India, China, and Burma. Originally, the fruit was not harvested for cooking purposes, but as an antidote for poisons. During the 15th century, the citrus was cultivated in Genoa; the fruit was introduced to the United States when Christopher Columbus brought lemon seeds with him. Here lemons were also mainly grown for ornamental or medicinal purposes, and it was not until the late 17th and 18th centuries that the fruit began to be harvested in the US for its flavor.

The citrus is used for its juice or its zest, or as a garnish. It can be macerated and added to liquor or made into a preserve. The acid from lemon juice is also used to tenderize meats in marinades, and the rind can also be pickled for a savory delicacy.