115 



YELLOW BIRCH. 

 Betula lutea, Michaux. 



FORM A large tree usually attaining a height of 00-80 ft. with a diameter of 2-3 ft., 

 hut may reach a maximum height of 100 ft. with a diameter of 3-4J feet. Trunk in the 

 open usually short, branching near the base; its long slender branches forming a wide open 

 rather hemispherical crown, in close stands often rather free from lateral branches. 



BARK Close and furrowed or peeling off in thin yellow film-like papery scales. Varies 

 with the age and location of the tree. On young trunks and branches rather close, shining, ' 

 yellow but soon forming a ragged fringe, later peeling off into thin, yellow, film-like, papery 

 layers. On old trunks it finally becomes reddish-brown and roughened with fissures. The ragged 

 bark is often pulled off and used by campers to start fires in wet weather. See Fig. 68. 



TWIGS At first green and hairy, later brown and smooth, finally dull silvery-gray. Terminal 

 twigs long and slender; lateral short nnd stout; usually covered with elongated horizontal 

 lenticels which in time unite to form a long horizontal line. 



BUDS Similar to those of the Black Birch, but sometimes slightly more downy. See 



page 118. 



LEAVES Alternate, simple, occur singly or In pairs but never opposite, 3-4 inches long, 

 ovate, wedge-shaped or heart-shaped at base, doubly serrate on margin, acute at apex, dull 

 green above, yellowish-green below. 



LEAF-SCARS Similar to those of the Black Birch in particular, and all of the other 

 Birches in general. 



FLOWERS Appear about April before the leaves. Staminate and pistillate separate, but 

 usually on the same branch. Staminate are formed in the fall, remaining over winter as 

 aments about 1 of an inch long which elongate to about 3 inches in spring. Pistillate about 

 s of an inch long, with acute scales which are light red and hairy above, and green below. 



FRUIT An erect, usually very short-stalke-I strobile, about 1-15 inches long, ovate in out- 

 line, consisting of numerous 3-lobed scales fastened to a central axis and bearing small 

 winged nuts with rather narrow wings. 



WOOD Diffuse-porous; rays indistinct; heavy, hard, strong, compact, not durable when 



in coutnct with the soil. Heart-wood light brown, tinged with red; sap-wood pale in color. 



Weighs 40.84 pounds per cubic foot. Used for furniture, flooring, interior finish, boxes, certain 

 veneers and fuel. 



DISTINGUISHING CHARACTERISTICS The Yellow Birch, also known as Silver and Gray 

 Birch, can readily be du-tinguished from the other Birches of Pennsylvania by its yellow bark 

 which peels off into thin, film-like, papery scales. Its method of peeling the bark resembles 

 that of the Paper Birch and the Red Birch, but it does not have the white color of the 

 former nor the reddish to greenish-brown color of the latter. The loose, film-like, papery scales 

 of the Red Birch are smaller than those of the Yellow Birch and the strobiles of the former 

 are slender-stalked while those of the latter are usually sessile or very short-stalked. 



RANGE Newfoundland, south to Pennsylvania, and along the mountains to North Carolina 

 and Tennessee, west to Minnesota. 



DISTRIBUTION IN PENNSYLVANIA Found locally throughout the State but most common 

 in the Alleghenies. Rare or absent in the southeastern and southwestern parts. 



HABITAT Common on moist rich uplands, borders of streams, and in swamps. 



IMPORTANCE OF THE SPECIES The Yellow Birch is one of the largest deciduous trees 

 of northeastern America. Until recently the value of its wood was not fully appreciated, 

 but today it holds a fair position on the lumber market and in the future it will no doubt 

 attain a still better position. It has been classed as one of the most artistic, reliable, and 

 versatile of the hardwoods of this country. With all its good qualities, it has superior 

 associates and consequently cannot be recommended for forestry purposes except on the 

 farmer's woodlot where fuel is especially desired and in such other places where it comes 

 up naturally and other more desired species will not grow to advantage 



