Lemons are a tart fruit that are yellow and have a rough outer skin while limes are smaller, come in a sweet or sour variety, and have a smooth green peel. Both fruits are available throughout the year, but the sweet lime is not readily available in the United States.
Lemons are generally more sour than limes because lemons contain more citric acid and sweet limes lack citric acid.
The scientific name for lemons is Citrus limon. They are oval in shape and have a very tart, acidic flavor. The two main types of lemons consumers are familiar with are the eureka and Lisbon varieties. The Lisbon often has a smoother skin and seedless fruit. The eureka lemon has a short neck on one end and contains seeds.
The scientific name for limes is Citrus aurantifolia and there are two main types of limes found in the U.S. are key and Tahitian. Tahitian limes contain less acid than key limes.
Lemons are a cross between limes and citron and have been around for about 2,500 years. Limes originated in Southeast Asia and they were introduced to Northern Africa and Egypt around the 10th century. Both have become popular and their flavors mingle well in a variety of food and beverages.