192 



SYSTEMATIC BOTANY. 



croton-oil is expressed. 



From JatropJm Cureas, a native of 

 Tropical America, pinhoen- 

 oil is obtained. From sev- 

 eral species of plants of this 

 family (especially Hevea Gfui- 

 nensis), Caoutchouc, or India 

 Rubber, 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 (Exccecaria se- 

 302 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 (Buxits sempervirens), 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. punieea from the "West Indies, E. pukherrima 

 (called also Poinsettia) from Mexico, and E, margirmta 

 from the western United States (Fig. 303). 



Fig. 302. KicimM communU, the Castor-OU Plant. 



