192 



SYSTEMATIC BOTANY. 



croton-oil is expressed. From Jairopha Curcas, a native of 



Tropical America, pinhcsn- 

 oil is obtained. From sev- 

 eral species of plants of this 

 family (especially Sevea Gui- 

 nensis), Caoutchouc, or India 

 Kubber, is obtained, which, 

 in its crude state, consists of 

 the dried, milky juice ex- 

 uding from incisions made 

 into the tree. The Tallow- 

 tree of China {Excwcaria se- 

 bifera), now cultivated in 

 America, has its seeds coated with a white greasy substance, 

 from which candles are manufactured. The Box-tree of 

 Europe and Asia {Buxus sempeiuirens), attaining a height 

 of ten to thirty feet, and a diameter of eight to ten inches, 

 furnishes the important, hard, and fine-grained timber 

 called box-wood, used in wood-engraving, the manufacture 

 of mathematical instruments, etc. The Dwarf Box, used 

 for bordering garden walks, is a variety of this species. The 

 African Teak ( Oldfieldia Africana) is a wood so hard and 

 heavy that it is now no longer in general use in ship-build- 

 ing, for which it was introduced into England in 1819. It 

 is adapted for steam vessels, as it stands a great degree of 

 heat. The genus Euphorbia, containing seven hundred 

 species, furnishes very many ornamental plants ; conspicu- 

 ous among these are Euphorbia splendens from Madagas- 

 car, E. punicea from the West Indies, E. pidchcrriwa 

 (called also Poinsettia) from Mexico, and E. marginata 

 from the western United States (Fig. 303). 



Fig. 302. Kicinus communis, the Caator-011 Plant. 



