DICOTYLEDONOUS PLANTS 



333 



monoecious, dioecious or rarely perfect; calyx regular; stamens 

 (when present) equal in number to the lobes of the calyx and 

 opposite them ; ovary one-chambered, 

 one-capsuled; fruit an achene or 

 a drupe, sometimes many fruits 

 united into a mass. A large fam- 

 ily of diversified characters, mostly 

 tropical. 



The elms (Ulmus}, of which 

 there are several species, are good 

 types of this family in which the 

 fruit is developed as a samara (Fig. 

 169). The American hackberry 

 (Celtis occidentalis) is another 

 familiar American tree; the com- 

 mon hop (Humulus lupulus} is a well-known vine which is 

 grown to some extent for its bitter and aromatic principles. 



The American red mulberry (Morns rubra) and the Asiatic 



FIQ. 168. Bur of native chest- 

 nut showing two seeds within. (Pro- 

 ductive Plant Husbandry.) 



Fio. 169. Flower of elm. 



white mulberry (M. alba} are well-known fruits. The silkworms 

 feed upon the leaves of the latter, which is grown extensively 

 for that purpose (Fig. 170). 



