“ As the stamens and pistil are borne by different flowers, cross-fertilization is necessary. In Mercurialis and others with inconspicuous flowers pollination is effected by the wind, but in many cases insects are attracted to the flower by the highly-coloured bracts, as in many Euphorbias and Dalechampia, or by the coloured calyx as in Manihot; the presence of honey is also frequently an attraction, as in the honey-glands on the bracts of the cyathium of Euphorbia. ”

“ Several members of the order are of economic importance. Manihot utilissima, manioc or cassava (q.v.) , is one of the most important tropical food-plants, its thick tuberous root being rich in starch; it is the source of Brazilian arrowroot. Caoutchouc or india-rubber is obtained from species of Hevea, Mabea, Manihot and Sapium. ”

“ In a great many genera the corolla is absent. The most reduced type of flower is that described in Euphorbia, where the male consists of one stamen separated from its pedicel by a joint, and the female of a naked tricarpellary pistil. The stamens are sometimes more or less united (monadelphous) , and in castor-oil (Ricinus) (fig. 3) are much branched. The ovary generally contains three chambers, and bears three simple or more often bipartite styles ”