EUPHORBIAOEX. 161 



Moreover, if we take account of the number of species proper to 

 America for the genera it has in common with the old world, we 

 calculate that it possesses altogether eighteen hundred and twenty- 

 two species of Euphorbiacece, the four hundred and fifty others 

 belonging to the old world. Everywhere, moreover, we find the 

 species are not in great number except in the warmest regions, 

 there being no exception but the genus Euphorbia. The family of 

 Eufhorbiacece represents very nearly, according to most calculations, 

 the fortieth part of the Phanerogamia^ distributed over the globe. 

 Europe is the poorest in genera of the five parts of the world, only 

 possessing five (besides the Callitriche), and even three of these,' 

 Tournesolia, Jndrachne, and Seeurinega, are only represented by a 

 single species, and the genus Mercurialis by four or five. The Aus- 

 tralian genera are frequently remarkable for a peculiar aspect and 

 foliage ; by their linear cricoid leaves, answering to the embryo with 

 narrow and semi-cyliudrical cotyledons ; to this country belong all 

 the genera with " stenolobate " embryos. There are besides in this 

 group, as in many others, a certain number of ubiquitous plants 

 which have followed man in his migrations, either on account of their 

 utility, or because the seeds are mixed with those of the crops. Such 

 are Euphorbia Lathyris, Peplus, Helioscopia, our annual Mercurialis, 

 and, in warm countries only, for they cannot support a rigorous 

 climate, several species of Phyllanthus and Acalypha, which, like 

 certain species of TJrtica, have become what are called, not without 

 reason, " the bad herbs of tropical regions ".^ 



The most active Euphorbiacese owe their properties ^ to the latex 

 or to the oUy and resinous substances contained ia the seeds.^ 

 Amongst these last, must principally be mentioned Euphorbia, 

 Ricinus, Jatropha, and Pignon cflnde (Fr.) The ancients fre- 

 quently employed, as evacuants, the seeds of Euphorbia Lathyris * 



' On the questionB of detaa touching the PI. DiapTior. 807-841, 1154. 



geographical distribution, see Endl. Enchirid. ' These seeds are, in the useful species, pro- 



689.— LiNDL. Veg. Kmgd. 276.— H. Bn. M. vided with albumen and an embryo. The 



Gen. Ewphwhiae. IVi.. — A. DC. Geogr. Bot. opinion (which must be abandoned), was for- 



JJais. 328, 686, 700, 707, 763, 759, 1045, 1281, merly everywhere professed that the principles 



etc. contained in the latter are completely diflFerent 



2 Endl. Enchirid. 590. — Lindl. Veg. Kingd. from those of the others, more acrid, more veno- 



276. — A. Juss. Euphorb. 73. — GruiB. Drag. mous. 



Simiil. 65.. 6, ii. 336-368.— Perbira, Ekm. * Euphorbia Lathyris L. Spec. 655. — DO. 



Mat. Med. ed. 4, ii. p. i. 399.— Kosenth. Syn. Fl. Fr. iii. 333.— Gken. et aoDR. Fl. de Fr 



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