76 KEY TO GENERA AND SPECIES 



continent. (Figs. 134, 135.) American 

 Canoe Birch, Paper Birch, Canoe Birch, 

 White Birch, Betula alba var. papyri/era 

 (Marsh.) Spach. 



ALDER. Shrubby, or occasionally small trees. 

 Flowers in catkins. Fruit clusters cone- 

 like. 



Fig. 136. Downy 

 Green Alder. 



Fig. 137. Speckled 

 Alder. 



Fig. 138. Euro- 

 pean Black Alder. 



1 19. Leaves broadest at the middle or below 120. 



119. Leaves broadest above the middle 121. 



120. Flowers in the spring. Leaves densely soft- 



hairy beneath. Branchlets hairy. Mature 

 fruit 5 to f of an inch long. Newfound- 

 land to western Mass, and N. Y. (Fig. 136.) 

 Downy Green Alder, Alnus mollis Fernald. 

 120. Flowers in the spring. Leaves somewhat 

 hairy or rusty beneath, dark green above, 



