TREES AND SHRUBS. 



385. Alder (Alnus glutinosa) grows chiefly in moist 

 places, beside streams and pools, in marshes and bogs, but 

 will thrive in drier places which 

 are sheltered or in which, the air 

 is moist enough. It is generally 

 a small tree, but may reach a 

 height of sixty feet ; the trunk, 

 however, rarely exceeds a foot 

 in diameter. 



The Alder is rather like 

 the Hazel in general mode of 

 growth, being often shrubby 

 owing to the production of 

 numerous stool-shoots, but the 

 roots rarely produce suckers. 

 On the older parts of the shoot 

 the bark is black and scaly ; on 

 younger parts it is brown, with 

 very distinct lenticels. 



The young leaves have sti- 

 pules which soon fall off ; the 



blade is broad and usually notched at the end, and except 

 at the base its edge is doubly toothed, the teeth being short. 

 The large egg-shaped brown resting buds are peculiar in that 

 each is on a stalk. The young leaves are pleated (Fig. 48, 

 plicate), and both they and the twigs are sticky at first. The 

 buds are covered by two or three scales, which are rather 

 difficult to separate and have a waxy coating. 



The catkins open in February before the leaves appear. 

 Both kinds of catkins can be seen in the previous autumn, 

 and in winter they are conspicuous on the bare twigs. 

 The ordinary resting buds of Alder contain only foliage- 



Fig. 160. Alder. 

 ivig with male catkins, young female 

 catkins (above), fruiting catkins (be- 

 low), and resting buds. 



The male catkins are cylindrical and are nearer the end 

 of the shoot than the shorter female ones. Each scale is 

 thickened at the outer edge and bears, on its (true) upper 

 surface, three flowers, each with a green four-lobed " calyx " 

 and four stamens. In the female catkin, which usually turns 

 upwards and does not droop like the open male catkin, each 

 scale bears two flowers resembling those of Hazel in struc- 

 ture but having no " calyx." 



