THE TREE. 



15 



LENGTH OF TIME THAT LEAVES OF CONIFERS REMAIN ON 

 TREES IN MINNESOTA. 



Flowers are parts of the plant especially modified for the 

 reproduction of the plant by seed. Both sexual organs may 

 be located together in the same flower, as those of the Bass- 

 wood, Mountain Ash and Cherry; or in separate flowers on 

 the same plant, as those of the Birch, Oak and Black Walnut; 

 or they may be separate on entirely different plants, as in the 

 Willow, Poplar, Boxelder and Ash. 



