The citron is a fragrant citrus fruit, botanically classified as Citrus medica by both the Swingle and Tanaka systems. The designation medica given it by Linnaeus is apparently derived from its ancient name “Median or Persian apple” that was reported by Theophrastus, who believed it to be native to Persia or the land of the Medes; there is no relation to medicinal uses of the fruit. Theophrastus notes its smooth sharp thorns, like those of a pear, the very fragrant but inedible ‘apple’, which keeps moths from clothes, and the fact that “it bears its ‘apples’ at all season; for when some have been gathered, the flower of others is on the tree and it is ripening others…. This tree, as has been said, grows in Persia and Media.” Citron was the first of the citrus fruits to appear in the Mediterranean Basin.
The fruit’s name derives ultimately from Latin, citrus, also the origin of the genus name, and as a result it has many similar names in many European languages, e.g. cederat, cédrat, cedro, etc. A source of confusion is that citron or similar words in French, Hungarian, Finnish, Latvian, the West Slavic languages and all Germanic languages but English are false friends, as they actually refer to the lemon. Indeed, into the 16th century, the English name citron included the lemon and perhaps the lime as well. Most other European languages, from Albanian and English to Spanish, use variants of the Arabic word laymun “limon”
While the lemon or orange are peeled to consume their pulpy and juicy segments, the citron’s pulp is dry, containing a small quantity of insipid juice, if any. The main content of a citron fruit is the thick white rind, which adheres to the segments, and cannot be separated from them easily.
Thus, from ancient through medieval times, the citron was used mainly for medical purposes: to combat seasickness, pulmonary troubles, intestinal ailments, and other disorders. The essential oil of the flavedo (the outermost, pigmented layer of rind) was also regarded as an antibiotic. Citron juice with wine was considered an effective antidote to poison, as Theophrastus reported.
Today the citron is used for the fragrance or zest of its flavedo, but the most important part is still the inner rind (known as pith or albedo), which is a fairly important article in international trade and is widely employed in the food industry as succade, as it is known when it is candied in sugar.
The citron is also used by Jews (the word for it in Hebrew is etrog) for a religious ritual during the Feast of Tabernacles; therefore is considered as a Jewish symbol, and is found on various Hebrew antiques and archeological findings. Citrons used for ritual purposes cannot be grown by grafting branches.
- In Iran, the citron’s thick white rind is used to make jam.
- In Pakistan the fruit is used to make jam as well as pickled.
- In South Indian cuisine, the citron is widely used in pickles and preserves.