THE STUDY OF FLOWERS. 



235 



forest trees, Poplar, Alder, Birch, Hazel, Beech, etc. A 

 study of these will reveal the fact that they do not produce 

 nectar and have none of the usual attractions for insects. 

 Pollination in such cases is effected by the wind. Examina- 

 tion of particular cases will repay study. Here the more 

 general facts regarding wind-pollinated plants may be set 

 down. Verification is expected as opportunity arises. 



Fig. 103. 



A, male catkin of Willows ; B, male flower ; C, female flower of ditto ; 

 D and E, female and male flower of Poplar. 



Abundance of Pollen. In Coniferae (Pine, Larch, etc.) 

 pollen is produced in enormous quantities. The pollen is 

 dry and powdery, and in many cases each grain is provided 

 with a pair of air sacs which serve to float the grain in the 

 air. Abundance of pollen is a necessity with all wind- 

 pollinated flowers. 



Extrusion of Anthers. This also is general, and is well 

 seen in Grasses, whose anthers are pendent (versatile) from 

 long swaying filaments (Fig. 102). 



