CITRON, a species of Citrus (C. medica), belonging to the tribe Aurantieae, of the botanical natural order Rutaceae; the same genus furnishes also the orange, lime and shaddock. The citron is a small evergreen tree or shrub growing to a height of about 10 ft.; it has irregular straggling spiny branches, large pale-green broadly oblong, slightly serrate leaves and generally unisexual flowers purplish without and white within. The large fruit is ovate or oblong, protuberant at the tip, and from 5 to 6 in. long, with a rough, furrowed, adherent rind, the inner portion of which is thick, white and fleshy, the outer, thin, greenish-yellow and very fragrant. The pulp is sub-acid and edible, and the seeds are bitter. There are many varieties of the fruit, some of them of great weight and size. The Madras citron has the form of an oblate sphere; and in the “fingered citron” of China the lobes are separated into finger-like divisions formed by separation of the constituent carpels, as occurs sometimes in the orange.
The citron-tree thrives in the open air in China, Persia, the West Indies, Madeira, Sicily, Corsica, and the warmer parts of Spain and Italy; and in conservatories it is often to be seen in more northerly regions. Sir Joseph Hooker (Flora of British India, i. 514) regards it as a native of the valleys at the foot of the Himalaya, and of the Khasia hills and the Western Ghauts; Dr Bonavia, however, considers it to have originated in Cochin China or China, and to have been introduced into India, whence it spread to Media and Persia. It was described by Theophrastus as growing in Media, three centuries before Christ, and was early known to the ancients, and the fruit was held in great esteem by them; but they seem to have been acquainted with no other member of the Aurantieae, the introduction of oranges and lemons into the countries of the Mediterranean being due to the Arabs, between the 10th and 15th centuries. Josephus tells us that “the law of the Jews required that at the feast of tabernacles every one should have branches of palm-tree and citron-tree” (Antiq. xiii. 13. 5); and the Hebrew word tappuach, rendered “apples” and “apple-tree” in Cant. ii. 3, 5, Prov. xxv. 11, &c., probably signifies the citron-tree and its fruit. Oribasius in the 4th century describes the fruit, accurately distinguishing the three parts of it. About the 3rd century the tree was introduced into Italy; and, as Gallesio informs us, it was much grown at Salerno in the 11th century. In China citrons are placed in apartments to make them fragrant. The rind of the citron yields two perfumes, oil of cedra and oil of citron, isomeric with oil of turpentine; and when candied it is much esteemed as a dessert and in confectionery. The lemon (q.v.) is now generally regarded as a subspecies Limonum of Citrus medica.
Oribasii Sardiani, Collectorum Medicinalium Libri XVII. i. 64 (De citrio); Gallesio, Traité du citrus (1811); Darwin, Animals and Plants under Domestication, i. 334-336 (1868); Brandis, Forest Flora of North-West and Central India, p. 51 (1874); E. Bonavia, The Cultivated Oranges and Lemons, &c., of India and Ceylon (1890).