BETULACEAE 



Sweet Birch 

 Betula lenta L, 



HABIT. A medium-sized tree 50-75 feet high and 1-2 feet 

 in diameter (max. 80 by 4Vi feet); rounded, open crown with 

 pendulous branches. 



LEAVES. Ovate to oblong-ovate; 2|^-4 inches long; usually 

 singly serrate; heart-shaped or unequally rounded at base; 

 dull, dark green and glabrous above, paler below; strongly 

 aromatic; with 9-11 pairs of veins. 



FRUIT. Strobiles oblong-ovoid, erect, nearly sessile, l-lVi 

 inches long; scales glabrous, longer than broad, with wide 

 lateral lobes; nutlet about as broad as wing. 



TWIGS. Smooth; lustrous; light red-brown; with strong 

 wintergreen taste (source of oil of wintergreen) . Winter buds: 

 V4 inch long, conical, acute, red-brown, divergent. 



BARK. Vi-Va inch thick; nearly black; not papery; breaking 

 into irregular, thin, scaly plates; smooth on young trees. 



WOOD. Important and similar to yellow birch. 



SILVICAL CHARACTERS. Intermediate in tolerance; 

 maturity reached in about 150 years; growth rather slow; re- 

 production not abundant; typical on moist sites, but hardy 

 on poor, dry soils; a scattered tree with mixed hardwoods. 



Gray Birch 

 Betula populifolia Marsh. 



This unimportant, small tree is typical on poor sites in the 

 Northeast. In its silvical characters it is similar to paper birch. 



LEAVES. Triangular to rhombic; long-pointed; doubly 

 serrate; with 5-9 pairs of veins; petioles slender, elongated. 



FRUIT. Strobiles cylindrical, pendant, on slender peduncles; 

 scales about as long as broad with recurved lateral lobes; nutlet 

 slightly narrower than wing. 



TWIGS. Resinous-glandular; red-yellow; not aromatic. 

 Winter buds: H inch long, ovoid, chestnut-brown, gummy. 



BARK. Thin; gray-white; close and firm; not papery or 

 exfoliating very slightly; black, triangular patches below branches. 



[153] 



