The citron (Citrus medica) is a species of citrus fruit. It usually has a thick rind and small sections. Originally, the tree came from Southeast Asia. Today it is mainly grown in Sicily, Morocco, Crete, and Corsica, as well as Puerto Rico. The tree can grow to a size of about 3 metres. The fruit can grow to a size of about 25 cm in length, and about 4 kg in weight. The pulp of the fruit is hardly ever used. The rind is used. It is made into an additive for cooking. Jam can also be made from the rind. The rind is also used to make vegetable oil, which is used for perfumes.

Generally, it is eaten preserved or in bakery goods, such as fruitcakes. (The candied peel rather than the fruit is often used in cooking.) In some cultures, it is made into a fruity tea. Pliny the Elder states that in his time , the citron could only be grown in Media and Persia (HN xii.7). The Romans tried to transport it into the Roman Empire in tightly packed pots, but failed, according to Pliny. There is evidence, however, which shows it was cultivated in the Mediterranean during Pliny's lifetime. Zohary and Hopf believe this tree was first domesticated in India. They think that its wild forms, along with those of the mandarin and pomelo, were the original citrus species.

The citron has many names in different countries; one popular reference is Cedrat, which is the French name for the fruit. Theophrastus referred to the citron as the Persian or Median Apple, and the fruit later came to be known as the Citrus Apple. Pliny calls the tree the Assyrian, or the Median, "apple" (the generic Greco-Roman name for globose fruits). Other citrus crops were not introduced to the Mediterranean basin until Islamic times.

In many languages other than English, a normal lemon is called a "citron" and a Lime is called a "limon". Although the East Asian citrus fruit yuzu (also called yuja) is sometimes called a citron, it is actually a separate species, Citrus junos.

Cultivation and uses 
The citron fruit is slow-growing. The citron tree is typically grown from cuttings that are two to four years old; the tree begins to bear fruit when it is around three years old. The fruit is oblong in shape, and sometimes as much as six inches in length. Its skin is thick, somewhat hard, fragrant, and covered with protuberances; the pulp is white and subacid. 

In Pliny's time the fruit was never eaten (it began to be used in cooking by the early 2nd century), but its intense perfume was used, penetrating clothes to repel noxious insects (compare Citronella). 

In Hebrew, the citron is known as the etrog (). It is one of the Four Species used during the holiday of Sukkot each fall. The role of the citron in that holiday was portrayed in the Israeli movie Ushpizin. Citrons that have been bred with lemon (in order to increase output per tree and make the tree less fragile) are not kosher for use as part of the Four Species.

In South Indian cuisine, especially Tamil cuisine, citron is widely used in pickles and preserves. In Tamil, the unripe fruit is referred to as 'narthangai', which is usually salted and dried to make a preserve. The tender leaves of the plant are often used in conjunction with chili powder and other spices to make a powder, called 'narthellai podi', literally translating to 'powder of citron leaves'. Both narthangai and narthellai podi are usually consumed with 'thayir sadam' (Curd Rice - Yogurt Rice).

In Korea, it is used to create a syrupy tea (called Yuja cha) where the slices of whole fruit are eaten with the sweet tea. The fruit is thinly sliced (peel, pith and pulp) and soaked or cooked in honey or sugar to create a chunky syrup. This syrupy candied fruit is mixed with hot water as a fragrant tea, where the fruit at the bottom of the cup is eaten as well. Often perserved in the syrup for the cold months, Yuja tea served as a source of fruit in winter. It is also popular in Taiwan, where it is known as 柚子茶 (Youzi cha).
[Note: The Korean Yuja is the same as the Japanese Yuzu 柚子 and must be different from the citron being described in this article. The Japanese Yuzu = Citrus junos.]

Notes

Related pages 
List of Citrus fruits

Other websites 
 Citrus medica used as a medicinal plant.