188 



FLOWERS 



the parts of each circle are not uniform in size and form the 

 flower is irregular. 



Pollination, or the transporting of the pollen to the stigma 

 of the flower, may occur in a number of ways. Pollination 

 of a flow r er by the pollen from its own stamens is self-pollina- 

 tion, flowers which are fertilized by their own pollen while 



FIG. 119. Dioecious flower of willow (Salix sp.) 



in the bud condition are cleistogamow, as the closed flowers 

 of the violet. The transportation of pollen from one flower 

 to the stigma of another flower is cross-pollination. In 

 anemophilous flowers cross-pollination is effected by the 

 wind. Wind-pollinated flowers are not so attractive as insect- 

 pollinated flowers, since they lack color, odor and nectar. 



