Lime citrus fruits at fruit market, farmer's market, front view, close-up

The lime is used in cooking around the world. As a citrus fruit, it is related to the lemon, orange, grapefruit and citron. It is the least sweet of the common citrus fruits, but its aromatic oils and strong, distinctive taste make it a popular flavoring agent. There are several types of limes, each with distinctive characteristics and uses. Some, like the Persian limes are perfect for everyday use, especially when juice is needed. Others, like kaffir lime, are better choices for zesting.

Persian or Tahitian Limes

Citrus latifolia, the Persian or Tahitian lime, is the most common lime in American supermarkets. Fairly large and quite juicy, it is the most adaptable in cooking. While they have a reputation for being tart, Persian limes are less tart than Key limes. They are also easier to grow and have a thicker skin, making them more suitable for packing and transport. Since they have the most juice of widely-available limes, they are also the best ones to use for recipes that call for fresh lime juice.

Mexican or Key Limes

Citrus aurantifolia, the Key or Mexican lime, is a small, round lime with a pale yellowish-green skin. What's the difference between lime and key lime? They are simply different varieties. Key limes are more acidic than Persian limes and have a distinctive aroma. The Key lime tree has dense foliage and many very sharp thorns, making them a less popular fruit crop than the Persian variety. Key limes pickled in salt water were a popular treat for children in the 1800s, as readers of Louisa May Alcott's "Little Women" will recall. Their juice is also typicall used in key lime pie.

Kaffir Limes

Citrus hystrix, the kaffir lime, also known as makrut lime, is another type of lime. It's unique among the citrus family for its skin, which is pebbly or warty in texture and rich in lime oil. Unlike other limes, the kaffir lime has very little juice. While the taste is a pleasant distinct and mild citrus flavor, the lack of juice means that typically, only the exterior is used. The leaves and zest are used widely in Thai cuisine, espeically saucy curries.

Australian Desert Lime

Citrus glauca, the Australian desert lime, is one of the smallest limes, not much larger than a marble. It is a prized "bush food" and is made into many commercial products, including marmalade and glacéed fruit. These aren't typically found in supermarkets, but may be found as ingredients in pre-packaged products.

Kalamansi or Calamondin

Citrus mitis, commonly known as kalamansi, calamondin, or musk lime, is a very tart lime that is widely used in Philippine cuisine. It is another very small lime, about an inch in diameter and orange in color. It has a very thin skin and does not store or transport well. Because the fruit takes nearly a year to fully ripen, the tree is frequently grown as an ornamental, both at full-size and as a bonsai. Don't expect to find these in the United States.

Rangpur Lime

The Rangpur or mandarin lime is not a true lime, as it is a hybrid of the lemon and the mandarin orange. However, because its juice is extremely acidic, it is often used as a substitute for true limes in cooking. Popular uses include pickling, candying and being made into spreadable marmalade.