24r THE SECOND BOOK OF BOTANY. 



EXERCISE VI. 

 Monoecious, Dioecious, and Polygamous Plants. 



When both staminate and pistillate flowers grow 

 upon the same plant (Fig. 16), it is said to be moncz- 

 cious. 



FIG. 16. 



A Monoecious Plant 



When staminate and pistillate flowers grow upon 

 separate plants (Figs. 18 and 19), such plants are said 

 to be dioecious. Fig. 17 represents a pistillate flower 

 from the female catkin (Fig. 18). Fig. 20 represents 

 a staminate flower from the male catkin (Fig. 19). 



