DICOTYLEDONES 



417 



are borne at the tips of the branches. The fruit in the Walnuts is a sort of 

 drupe ; that of the Hickories has the outer pericarp split into lobes. The 

 leaves are pinnately compound. The family is especially well represented in 

 the United States. 



FIG. 398. Carya (Hicoria) microcarpa. A, male, S, female, flowers. 

 (After BAILEY.) 



Order VIII. Fagales 



The Fagales include two very important families of trees : the Betulaceae, to 

 which belong the Birches (Betula) and Alders (Alnus), Hornbeam (Ostrya, 

 Carpinus), Hazel (Corylus); and the Fagacese, which comprise the Oaks (Quer- 

 2s 



