European Alder 



265 



region; it is a shrub or small tree, when first discovered supposed to be the 

 same as the well-known European Alnus incana, but subsequent study has 

 shown it to be quite different from 

 that species; the largest individual 

 tree observed was about 8 meters 

 high, with a trunk 1.5 dm. thick. 



The bark is brown, smooth or 

 nearly so, the young twigs slender, 

 densely brownish-hairy, becoming 

 smooth and gray-brown the second 

 season. The leaves are rather thin 

 in texture, oblong to obovate, acute 

 at both ends or bluntish at the apex, 

 8 to 12 cm. long, 6 cm. wide or less, 

 sharply irregularly toothed, densely 

 hairy on the prominent veins beneath, 

 otherwise smooth or nearly so, dark 

 green on the upper surface, pale green 

 on the lower; the leaf -stalks are about 

 I cm. long and very hairy. The fruit- 

 ing catkins are numerous, oblong. Fig. 224. -New York Alder, 

 short-stalked, 1.5 cm. long, their scales triangular- wedge-shaped, 3 to 4 mm. long, 

 toothed at the summit, the nut oval, half longer than wide, narrowly margined. 



8. EUROPEAN ALDER— Alnus 



rotundifolia Miller 



Betula Alnus glutinosa Linnseus 



Alnus glutinosa Gaertner 



This European tree has escaped from 

 cultivation and become estabhshed in New 

 Jersey, southern New York, eastern Mas- 

 sachusetts, and near Chicago; it reaches, 

 in Europe, a height of 25 meters, with a 

 trunk nearly a meter in diameter. 



Its bark is dark brown, rather thin, and 

 nearly smooth. The young twigs are loosely 

 hairy, soon becoming smooth. The buds 

 are smooth, glutinous, narrow, blunt, 8 to 

 10 mm. long. The leaves are broadly oval 

 to orbicular or obovate, thick, dark green, 

 dull, often blunt at both ends, but com- 

 monly more or less narrowed at the base, toothed or doubly toothed, glutinous, 



Fig. 225. — European Alder. 



