SPERMATOPHYTA URTICALES 



405 



Ulmaceae, the elms ; Moraceae, the mulberries, and Urticaceae, the nettles. The 

 Castlloa elastica of Mexico, the bread nut tree of Central America (Brosimum 

 Alicastrum) and the Cecropia of tropical America furnish rubber. 



Fig. 185. Yellow P>irch (Be f : >i /?i.Va). Flowering branch. 2. 

 Staminate flower, enlarged. 3. Pistillate flower, enlarged. 4. Fruit- 

 ing branch. 5. Nut. enlarged. 6. Scale of fruiting catkin, enlarged. 

 7. Winter branch, showing staminate catkin. 1, 4, 7, one-half natural 

 size. (After M. M. Cheney, In Green's Forestry of Minnesota.) 



The family Moraceae contains the bread fruit (Artocarpus incisa) an im- 

 portant article of food for the natives of the Pacific Islands, and the jack 

 fruit (A. integrifoha) the fleshy envelopes of which are, however, somewhat 

 poisonous. Canoe-gum, a very good substitute for rubber, is obtained from 

 this genus. The figs belong to this family also; the sycamore fig tree (Ficus 

 Sycamorus) produces small fruit which is used in Egypt for food. The com- 

 mon fig (Ficus Carica) is the most valuable; it includes the common and 

 Smyrna fig of commerce, containing 60-70 per cent of grape sugar. The India 

 rubber tree (F. elastica) is the source of some of the India rubber. The ban- 



