Spurge
2 of the 7 encyclopedias on this shelf carry an entry for Spurge. Both are reproduced below, so you can see where they agree and where they differ.
Aiton's Encyclopedia (1910)
spurj, a large genus of plants, the botanical name of which is Euphorbia. The spurges vary greatly in habit. In the eastern part of North America there are a dozen prostrate or spreading spurges, having slender stems like those of the marsh cranberry and small, one-sided, smooth, or hairy leaves shaped like a mouse's ear. They are much more delicate plants than purslane. When a stem or leaf is broken, a drop of white fluid oozes or spurges out. Other American species are erect, perennial herbs. Some of the tropical spurges, especially of Africa, have leafless stems like those of the tree cactus. They are covered with prickly spines. However widely the spurges may differ in appearance their flowers are all small, naked, and inconspicuous. A triangular seed pod, shaped somewhat like a grain of buckwheat, protrudes on a slender stem amid a cluster of greenish stamens. This pod is three-angled, and contains three seeds, often curiously pitted and wrinkled. Once the observer's attention has been directed to the spurges, the entire group will be found full of interest. The triangular stalked seed pod and milky sap are sufficient means of identification. There are about 600 spurges. The Euphorbia family, to which the spurges belong, comprises not less than 3,000 species. They are especially numerous in Australasia. Several plants of the family furnish caoutchouc from which India rubber is made. The castor-oil plant belongs also to this family.
Collier's New Encyclopedia (1921)
a vast genus (upward of 700 species) of herbs, shrubs, or soft-wooded trees with fleshy branches, abounding in milky juice. An extensive group, abounding in South Africa, have suc- 40 SPURGEON, CHARLES HADDON culent, spiny or unarmed, often melonshaped or cactus-like stems. The flower heads resemble single flowers, consisting of a calyx-like cap-shaped involucre, with 4-5 teeth, alternating with as many large horizontal glands, which enclose 10-15 male and 1 central female flower; the capsule separating when ripe into its three 2-valved constituent carpels. The genus is represented in all climates excepting the Arctic. Eleven non-important species are natives of Great Britain, and three others are more or less naturalized. Of the latter the caper spurge (E. Lathyris) has seeds containing a powerfully purgative oil. The most noteworthy medicinal species are E. resinifera, furnishing the intensely acrid gum-resin known in commerce as euphorbium, used principally as a vesicant in veterinary p cinary practice; E. ipecacuanha of North America - -called wild ipecac - the root bark of which possesses emetic, expectorant, and cathartic properties; E. corollata, of which the root is officinal in the United States pharmacopœia as an emetic; and E. neriifolia of India, yielding a juice employed externally in native medicine, while the root is used as a remedy in snake bites, Various species with brilliant scarlet bracts are grown for ornament.