580 



EUPHOEBIACB^. 



Euphorbias of Britain there is an evident involucre, surrounding a 

 number of achlamydeous male and female flowers, which by Linnseus 

 were looked upon as merely stamens and pistils, and hence the plants 

 were put by him in Dodeoandria in place of Monoeoia (p. 220). 

 The flowers in Euphorbiacese vary much in the number of their parts, 

 as may be seen in figs. 644-649, p. 368. Sometimes the general 

 pendunole or rachis becomes flattened and leaf-like (fig. 250, p. 173). 

 The inflorescence is occasionally amentaceous, as in the division 



Fig. 

 821. 



Fig. 

 820. 



Fig. 817. 



Fig. 818. 



Fig. 823. Pig. 822. Fig. 819. 



Scepacew, which is described by some as a distinct order. The plants 

 of the order abound in warm regions, especially in Equinoctial 

 America, where they occur as trees or bushes, or lactescent herbs, and 

 often present the appearance of Oactacese, from which their milky juice 

 at once distinguishes them. They are also found in North America and 

 in Europe. In Britain there are 3 genera and 17 species. There are 

 about 180 known genera and about 3000 species. Examples — 

 Euphorbia, Hippomane, Hura, Acalypha, Oroton, Jatropha, Kicinus, 

 Phyllanthus, Buxus. 



The plants of this order are acrid and poisonous, in some instances 

 furnished with stinging hairs. These properties reside especially in 

 their milky juices, which are contained in laticiferous vessels (fig. 68, 



Figs. 817-823. Organs of fructification of Euphorbia palustris, to illustrate the natural 

 order Euphorbiacese. Fig. 817. Inflorescence, with the involucre, i i, opened and spread 

 out, to show the position of the male and female flowers, which it encloses, g g. Glands 

 (glandular lobes) alternating with'the divisions of the involucre. 6 h, Membranous laminj£, 

 or bracts, at the base of the flowers, /m, fm,y Achlamydeous male flowers, consisting of a 

 single stamen, supported on a pedicel, to which it is attached by an articulation, ff, 

 Achlamydeous female flower in the centre; the ovary and styles supported on a long 

 pedicel. Fig. 818. Achlamydeous male flower sepai-ated. &, Bract, p, FediceL /, Fila- 

 ment articulated with the pedicel, ct. Anther. Fig. 819. Female flower, p, Summit of 

 the pedicel which supports it. c, A flattened portion of the pedicel, which some call a 

 perianth, o, Tricoccous ovary, s. Styles and stigmas. Fig. 820. One of the cocci 

 (carpels), c, separated, and seen on its inner surface, g, The seed seen across the Opening 

 by which the nourishing vessels enter. Fig. 821. A coccus separated, after dehiscence 

 and expulsion of the seed. Fig. 822. Seed separated. Fig. 823. Seed cut vertically. 

 (, Integument (spermoderm). p, Perisperm (fleshy albumen), e. Embryo with flat.cotyledons 

 and a superior radicle. 



