THE ALDEE. 



M'mts fflulino'sa Medio. 



The small Order of catkin-bearing trees, the Betula'cece, 

 includes only the two genera Bet'ula, the Birches, and 

 Alnus, the Alders. These are, as we have seen, 

 mainly distinguished by the character that, whilst 

 in the Birch the scales constituting the fruit-bearing 

 catkins are thin, and fall off simultaneously with the 

 fruit itself, in the Alders these scales become thick 

 and woody, and remain on the tree as a minute cone 

 after the fruits have been discharged. 



The few species constituting the genus Alnus are 

 shrubs or trees, seldom reaching a large size, and 

 range from Japan through Asia to the north of the 

 Himalayas, throughout Europe, North Africa and 

 North America, and along the Andes into Chili ; 

 but our one British representative of the group is 

 confined to the Old World. Its distinctive feature is 

 its leaves, which are roundish, with a wedge-shaped 

 base, a wavy and shghtly toothed margin, and a 

 short stalk, whilst they are hairy and glutinous when 

 young — whence the specific name, A. glutinosa — and 

 glossily dark olive-green on both surfaces later on. 



Though it may grow to a tree of considerable size, 

 even reaching a height of seventy feet, and more than 

 nine feet in girth, it does not usually exceed thirty 

 or forty feet in height, or six feet in circumference, 

 and is so commonly treated as coppice that it is most 

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