^ CHAPTER XXIV: THE ALDERS 



Family Betulace^ 



Genus ALNUS, Linn. 



Small water-loving trees of rapid growth. Leaves simple, 

 deciduous, alternate, short stemmed. Flowers apetalous, monoe- 

 cious, in catkins. Fruit woody, cone-like, oval, with 2 seeds 

 on each scale. 



KEY TO SPECIES 



A. Flowers in autumn. {A. maritima) seaside alder 



AA. Flowers before leaves in winter or early spring. 



B. Staminate catkins becoming 4 to 6 inches long. 



C. Bark smooth, pale grey or white; tree with nar- 

 rowly pyramidal head. {A. Oregona) red alder 

 CC. Bark ridged, dark brown; tree with wide, open 



head. (A. rhomhijolia) white alder 



BB. Staminate catkins becoming 2 to 3 inches long. 

 C. Leaves narrow, tapering to base and apex. 



{A. ohlongijolia) lanceleaf alder 

 CC. Leaves broad, oval, papery. 



{A. ienuijolia) paperleaf alder 

 AAA. Flowers after the leaves in spring or summer. 



{A. Sitchensis) Alaska alder 



The genus Alnus includes twenty species of shrubs and trees, 

 nine in North America, six of which are trees in habit and size. 

 The largest and most important timber tree is the black alder 

 of the Old World. Widely distributed by Nature and by man, 

 this genus is the source of many hardy ornamentals adapted to 

 damp soils. 



"Alder, the owner of all waterish ground." 



Seaside Alder (Alnus maritima, Nutt.) — A round-topped 

 tree 15 to 30 feet, with slender branches. Bark thin, smooth, 

 light brown ; twigs greyish. ^Vood soft, light brown, close grained. 



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