Everyone knows that there are a wide variety of citrus fruits, including limes, lemons, oranges, grapefruit, etc. But all of the citrus fruits we know were developed from just a few that occur in the wild, including citron, pomelo, and mandarin. The variety of citrus fruits we encounter at the grocery store in the winter months are mostly hybridized from those species and their descendants.
Citron (Citrus medica) is the citrus fruit that gave “citrus” its name. Records of the fruit go back thousands of years in Mesopotamia, although its origin may be India or Southeast Asia. Citron is more temperature-sensitive than other commercial citrus grown in the U.S. but flourishes in South America and the coastal areas of the Mediterranean. Americans are mostly familiar with citron as a candied ingredient in fruitcake, made from the fruit’s peel.
The pomelo (Citrus grandis) is the largest of all citrus fruits. They can grow up to nine inches in diameter and weigh over four pounds! Pomelos are native to Southeast Asia, but are gaining popularity worldwide. They appear green or yellow when ripe, and the flesh is white or shades of pink. The taste is like a sweet grapefruit, and in fact, grapefruit is sometimes called pomelo and the pomelo is sometimes called Chinese grapefruit, although they are different fruits.
The mandarin (Citrus reticulata), or mandarin orange, is one of the oldest citrus fruits, and the ancestor of many other fruits we know. It is a small, sweet-tasting orange originating in Southeast Asia. Mandarins are also distinct from oranges in that they are easy to peel. It has some close relatives that are sometimes hard to distinguish. Tangerines (Citrus tangerina) are closely related to mandarin oranges, although the name is usually reserved for the more reddish fruit. They are named after the city of Tangier, Morocco, from where they were exported to Europe. Clementines (Citrus ×clementina) are hybrids developed from crossing a Mandarin orange and a sweet orange.