The citron is a large fragrant citrus fruit with a thick rind, botanically classified as Citrus medica by both the Swingle and Tanaka botanical name systems. It is one of the four original citrus fruits (the others being pomelo, mandarin and papeda), from which most other citrus types developed through natural hybrid speciation or artificial hybridization.
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 to be a Jewish symbol which is found on various Hebrew antiques and archaeological findings.Citrons used for ritual purposes cannot be grown by grafting branches.
The citron tree, called the Assyrian, and by some the Median apple, is an antidote against poisons. The leaf is similar to that of the arbute, except that it has small prickles running across it. As to the fruit, it is never eaten, but it is remarkable for its extremely powerful smell, which is the case, also, with the leaves; indeed, the odour is so strong, that it will penetrate clothes, when they are once impregnated with it, and hence it is very useful in repelling the attacks of noxious insects.
The tree bears fruit at all seasons of the year; while some is falling off, other fruit is ripening, and other, again, just bursting into birth. Various nations have attempted to naturalize this tree among them, for the sake of its medical properties, by planting it in pots of clay, with holes drilled in them, for the purpose of introducing the air to the roots; and I would here remark, once for all, that it is as well to remember that the best plan is to pack all slips of trees that have to be carried to any distance, as close together as they can possibly be placed.