LOCUST-TREE, Ceratonia Siliqua, L., the carob-tree, of the tribe Cassieae of the order Leguminosae, is the sole species, widely diffused spontaneously and by cultivation from Spain to the eastern Mediterranean regions, and from Egypt to Bornou in Central Africa (Hogg, Hooker’s Journ. of Dot., i. 113), and imported to Hindustan (Graham, p. 254). It differs from all leguminous plants by the dilated disk to the calyx. It has no petals, and the flowers are polygamous or dioecious. The legume is compressed, often curved, indehiscent, and coriaceous, but with sweet pulpy divisions between the seeds, which, as in other genera of the Cassieae, are albuminous. The pods are eaten by men and animals, and in Sicily a spirit and a syrup are made from them. These husks being often used for swine are called swine’s bread, and are probably referred to in the parable of the Prodigal Son. It is also called St John’s bread, from a misunderstanding of Matt. iii. 4. The carob-tree was regarded by Sprengel as the tree with which Moses sweetened the bitter waters of Marah (Exod. XV. 25), as the kharrub, according to Avicenna (p. 205), has the property of sweetening salt and bitter ’ waters. Gerard (Herball, p. 1241) cultivated it in 1597, it having been introduced in 1570 (Loudon’s Arb., ii. 660). For various names, extent of distribution, historical references, &c., see Pickering’s Chrom Hist, of Ph, p. 141.