117 



GRAY BIRCH. 



Betula populifolia, Marshall. 



FORM A small tre usually occurring in clumps and attaining a height of 20-30 ft. with 

 a diameter of 9 inches, but may reach a height of 45 ft. and a diameter of 18 inches. 

 Trunk slender, often inclined, continuous, and covered with ascending lateral branches with 

 drooping ends which form a narrow pyramidal, rather open, and pointed crown. 



BARK Dull white, close, smooth, not peeling off into thin film-like layers but covered with 

 triangular black spots below the insertion of the lateral branches. On old trunks black and 

 roughened with fissures. Inner bark orange-yellow. See Figs. 64 and 69. 



TWIGS Slender, greenish to brown, roughened by warty exudations and by raised, pale, 

 and horizontally-elongated lenticels; later smooth and dull white. 



BUDS Alternate, 2-ranked, ovate, 1/5 of an inch long, sharp -pointed, divergent, covered 

 with 3-4 visible smooth, slightly resinous, brown bud-scales with downy margins. 



LEAVES Alternate, simple, triangular, ovate, 2J-3 inches long, lj-2 inches wide, wedge- 

 shaped at base, decidedly serrate on margin, with long-toothed apex and long, slender 

 petioles which cause the leaves to quiver when stimulated by a slight breeze only. 



LEAF-SCARS See "Leaf-Scars" under Black Birch, page 118. 



FLOWERS Appear about April before the leaves. Staminate in solitary or occasionally 



paired aments which are about 11-15 inches long and 1 of an Inch wide during the winter, 



but develop in spring to a length of 2-4 inches. Pistillate cylindrical, slender, about J of 

 an inch long and stalked. 



FRUIT A slender, cylindrical, stalked strobile about I of an inch long and obtuse at the 

 apex. Scales small an3 downy; their lateral lobes broad and recurving, while the terminal 

 one is rather straight and narrow. Seeds small, oval,* and winged. Wings broader than 

 the seed. 



WOOD Diffuse-porous; rays inconspicuous; light, soft, not strong, not durable; heartwood 

 light brown; sapwood light. Weighs 35.90 pounds per cubic foot. Used for fuel, and in the 

 manufacture of paper pulp, spools, shoe pegs, and hoops for barrels. 



DISTINGUISHING CHARACTERISTICS The Gray Birch, also known as Oldfleld, White, 

 Poverty, or Poplar Birch, can be distinguished from all the other Birches of Pennsylvania, 

 except the native Paper Birch, and the commonly introduced European White Birch, by 

 its white bark which Is never renewed when once removed. The bark is close, dull white, 

 and marked with black triangular blotches just below the insertion of the lateral branches, 

 and does not peel off in thin paper-like layers like that of the Birch. The Gray Birch is 

 usually a small tree with a rather continuous trunk and frequently occurs in clumps. The 

 twigs ' of the Gray Birch are also rougher than the Paper Birch and its leaves are long- 

 acuminate, while those of the Paper Birch are ovate. 



RANGE Nova Scotia south to Delaware and southern Pennsylvania, west to the southern 

 shores of Lake Ontario. 



DISTRIBUTION IN PENNSYLVANIA Locally in the mountainous portion. Common in 

 Monroe, Schuylkill and Pike counties. Abundant along streams in northern part of the State. 

 A few specimens found on top of South Mountains in Franklin county near Mason and Dixon 

 line, and on Tussey mountain in Huntingdon county. 



HABITAT Usually occurs on moist soil along streams, ponds, and lakes; also grows on 



hillsides and occasionally on rocky mountain tops. 



IMPORTANCE OF THE SPECIES This species is of little commercial value on account of 

 the small size which it attains due to its short life. The existing stands should, however, be 

 conservatively utilized. It cannot be recommended for forest planting, but Is an extremely 

 attractive tree for ornamental purposes. 



