188 



BETULACE^. 



[piRT I, 



THE GENUS BETULA. 



The common Birch (Betula alba) is an ex- 

 ceedingly graceful tree. The male 

 catkins are produced singly, or two 

 or three together. They are long, 

 slender, loose, and gracefully droop- 

 ing ; {see Jig. 83 ;) and each consists 

 _cat ^^ ^ great number of flowers, pressed 



Krxs OF THE close together, and growing round a 

 rachis or stem, as shown in the 



catkin a in Ji^. 84, from which some of the 



flowers have been removed. The male flowers 



have each ten or 



twelve stamens 



enclosed in three 



or more scales or 



bracts, as shown 



in a reversed 



flower at b. The 



female flowers are 



produced in dense 



catkins, which 



are much shorter 



than the others, 



and always soli- 

 tary; the flowers, 



which are arrang- 

 ed round a very slender axis, are furnished with 



lobed scales, and c is a scale with three female 



Fm. 84.— The Birch {Betula). 



