Euphorbiacese, the fourth largest natural order of Dicotyledonous plants, comprising over 3,000 species in over 200 genera. Having diclinous flowers which are usually monochlamydeons, the order is classed among the Incompletes. Though half its species belong to tropical America, the genus Euphorbia contains 700 species, many belonging to Africa, and others scattered over nearly the whole world. They vary immensely in size and habit from large trees to tiny herbs; but almost all agree in having a milky, acrid, poisonous juice. Their leaves are generally scattered, simple and stipulate, and their flowers typically pentamerous. The stamens may be indefinite in number and free, monadelphous or polyadelphous. The ovary is superior, and generally composed of three carpels, which separate more or less elastically from a central carpophore, and contain one or two seeds, which are pendulous, albuminous, and often arillate. The genus Euphorbia is singularly varied in habit, some African species being 30 to 40 feet high and 2 feet in diameter, and others succulent and angular, with their leaves reduced to spines so as to closely resemble the Cactaceee (q.v.), whilst our British species are mostly mere weeds with foliage often of a vivid green. All agree, however, in the character of their inflorescence. This is surrounded by a cup-like involucre or "cyathium," with four or five marginal lobes alternating with glandular structures. Within this cup are several male flowers and one female one in the centre. The former each consist of a single stamen, the junction of its filament; with its pedicel suggesting an articulated filament. The female flower is also pedicellate, hanging over the edge of the cyathium, and none of the flowers have any perianth. Euphorbia resinifera, a native of the Barbary States, yields on incision the acrid resin known as Gum Eiipliorbiuin, formerly used medicinally; E. Cattimandoo, of Madras, yields the caoutchouc Cattimandoo; and E. Drummondii, the alkaloid Drumine, which has anaesthetic properties like those of cocaine. The poisonous properties of most members of the order are more or less dissipated by heat, so that many are used as food. Of these the most important is the Manioc (Manihot), the source of cassava (q.v.) and tapioca. Other valuable plants belonging to this order are the various species of Hevca yielding the caoutchouc of Brazil; Ricinus communis yielding castor oil (q.v.); Croton Tiglium, from which croton oil (q.v.), and C. Eleutcria, from which Cascarilla bark (q.v.) is obtained. From Alenrites triloba, candle-nut, country walnut, or kekune oil is obtained in the Fiji and Sandwich Islands, and Stillingia sebifera is the Chinese tallow-tree. Crozophora tinctoria, the "turnsole" of the Mediterranean region, and Mallotus philippinensis, "kamala" or "wars," yield dyes; Hura crepitans has a large woody fruit, which, though singularly explosive, can be prepared as a sand-box, whence the tree takes its name; and the box-wood (q.v.), Buxus seinpervirens is so closely related to the order as generally to be classified with it.