BETULACEAE 



Yellow Birch 

 Betula alleghaniensis Brit. {Betula lutea Michx.) 



HABIT. A tree 60-80 feet high and 1-2 feet in diameter 

 (max. 100 by 4 feet); with rounded, open crown and pendu- 

 lous branches. 



LEAVES. Ovate to oblong-ovate; 3-5 inches long; sharply 

 doubly serrate; rounded, inequalateral base; dull, dark green 

 and glabrous above, paler below; slightly aromatic; with 9-11 

 pairs of veins. 



FRUIT. Strobiles ovoid, erect, nearly sessile, 1-1 Vi inches 

 long; scales hairy, longer than broad with wide lateral lobes, 

 tardily deciduous; nutlet about as broad as wing. 



TWIGS. Smooth; lustrous; yellow-brown to dark brown; 

 with slight wintergreen taste (source of oil of wintergreen). 

 Winter buds: lateral K inch long, ovate, acute, chestnut-brown, 

 ciliate on scale margins. 



BARK. Thin; dirty yellow to bronze colored; separating 

 horizontally into thin, papery, curled strips. 



WOOD. Very important, supplying about 75 per cent of birch 

 lumber; used for furniture, flooring, veneer, etc. 



SILVICAL CHARACTERS. Intermediate in tolerance; 

 maturity reached in about 150 years; growth rather rapid; 

 reproduction vigorous; shallow roots; restricted to cool, moist 

 sites; in mixtures with conifers and hardwoods. 



* * * 



River Birch 



Betula nigra L. 



This unimportant species is a medium-sized tree typical of 

 stream banks. It is quite similar to yellow birch in appearance 

 and silvical characters and diff'ers from it in the following ways: 



LEAVES. Rhombic-ovate and often lobed; base wedge- 

 shaped; more or less hairy below; with 5-9 pairs of veins. 



FRUIT. Unique in that it matures in May or June; strobiles 

 oblong, erect, on stout peduncles; scales with narrow, hairy, 

 erect lobes. 



TWIGS. Red-brown; hairy at first; not aromatic. Winter 

 buds: 14 inch long, woolly through summer. 



BARK, Thin; salmon-pink to red-brown; separating into 

 thin, papery, curled strips; furrowed and scaly at base of old 

 trees. 



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