Euphorbia, the typical genus of the botanical family euphorbiaceoe, or spurges, said to have been so named from Euphorbus, physician to Juba, king of Mauritania. The flowers are monoecious, collected within an involucre often closely simulating a calyx or corolla; male flowers consisting of a single stamen on a pedicel arising from the axil of a minute bract at the base of the involucre; fertile flower solitary in the middle of the involucre, consisting of a three-celled, three-lobed ovary, with a mere vestige of calyx, and borne on a pedicel which finally elongates and inclines to one side of the involucre; styles three, stigmas six. The pod separates into three one-seeded carpels. Plants or shrubs, often with a milky, acrid juice. The leaves are whorled or opposite, and sometimes wanting, the stem being succulent, and the plant assuming the appearance of a cactus. It is a cosmopolitan genus of many and diverse species. Some are commonly cultivated as ornamental plants, as E. pulcherrima (Poinsettia) of Mexico, whose floral leaves are 4 or 5 in. long and of the brightest vermilion red; E. splendens of the Mauritius, with thick, prickly stems, and cymes of deep red bract-surrounded flowers.
The gum resin, euphorbium, is gathered in Africa from E. officinarum and E. antiquorum, and in the Canaries from E. Cana-riensis;. it flows from incisions made in the stems, and is extremely acrid, producing violent inflammation of the nostrils in those who handle it. In India this gum is used externally in rheumatism, internally in cases of severe constipation. E. Tirucalli is common near Madras, where it is used for hedging; no cattle will touch the leaves; the fresh juice of this species is used as a vesicant. The roots of many species are emetic. Of our native species, the principal and the only one of general interest is E. ipecacuanha (wild ipecac), which was considered by Barton equal in value to the genuine ipecacuanha (cephaelis), and it possesses the advantage of having no disagreeable taste or smell. E. lathyris was one of the plants Charlemagne in his capitularies commanded to be cultivated in all monastic gardens, as its seeds were purgative and known as semina cataputice minoris. It is said that the capsules of this plant stupefy fish; it is well known that E. Hibernica and E.piscatoria are so used, and so powerful is the former that a small basketful of the bruised plant will stupefy the fishes for several miles down a river.
E Cattimandu furnishes a caoutchouc; and notwithstanding the generally poisonous qualities of the genus, E. edulis is a pot herb, its acrid qualities being dispelled by boiling. E. balsamifera is used in the same way. Many species of euphorbia grow in poor sandy soil, through which the roots penetrate to a depth of several yards. Violent vomiting and purging are often produced in children by eating the seeds of a variegated-leaved euphorbia cultivated as an ornamental plant. The uncertainty of their action forbids their general use as medicine.