[31] 



A decoction made of its bark, mixed with ferruginous solutions, yields a black 



color. 



The glaucous alder, Alnus glauca, Mich., is a tree of the United States, 

 remarkable for the color of its leaves. It grows about twenty feet high. The bark is very 

 dark brown. The leaves are oval, bidentate, green above and bluish underneath. The male 

 flowers form long slender catkins. The female catkins are rounded, almost sessile, two or 

 three together. Their peduncle has two large stipules at its base. 



FLOWERS: in February and March. 



RANGE: North America, acclimatized in our gardens. 



CULTIVATION. Alders are very hardy. They grow rapidly in wet areas and 

 proliferate abundantly via seeds. To plant the seeds, the cones are collected around mid- 

 October. When the scales begin to open, they're spread out in a very dry place. When 

 spring arrives and the time for planting is at hand, the cones are put in a sack and shaken 

 vigorously to release the seeds. 



KEY TO PLATES. 



Common alder. 1. Leaf, natural size, seen from below. 2. Male catkin. 3. Cross 

 section of female catkin showing insertion of seeds. 4. Detached scale of female catkin. 5. 

 Seed. 



Glaucous alder. 1. Female catkin. 2. Scale of female catkin. 3. Ovary. 



