MORPHOLOGY OP LEAVES AND FLOWERS 



607 



Fig. 4 63. I and III. Staminate and pistillate catkins of the Willow. II and IV. 

 Staminate and pistillate flowers. V. Cross section of ovary showing the 

 one cell, two placentae and ovules. VI and VII show opening of pod 

 and character of the seed. Since the male and female catkins are borne 

 on different trees, this plant is dioecious. 



(After Thome.) 



