116 



RED BIRCH. 

 Betula nigra, Linnaeus. 



FORM — A medium-sii.ed tree usually attaining- a height of 30-50 ft. with a diameter of 1-2 

 ft., -but may reach a height of 100 ft. witn a diameter of 5 feet. Trunk usually short and 

 divided near the base Into a few sliglitly diverging limbs. Crown rather narrow, oblong, 

 and irregular. 



BARK — Varies with the age of the tree and its location on the trunk.. On lower part of 

 old trunks^ dark reddisii -brown and rongheneci by fissures which separate irregular scales. 

 On younger trunks and upper portion of older ones peels ofE into thin, film-like, papery scales 

 which are reddish-brown to gi-eeuish-brown in color and persist for a few years during which 

 time they form a ragged fringe and expose the light red and close bark underneath. See 

 Pig. 65. 



TWIGS — Slender, at first hairy and greenish, later smooth, reddish-brown, covered by pale 

 horizontally-elongated lenticels. 



BUDS — Alternate, ovate, sharp-pointed, shining, smooth or slightly hairy, covered withj 

 usually 3-7 chestnut-brown overlapping scales. 



LEAVES — Alternate, simple, broadly ovate, li-3 inches long, wedge-shaped at base, acute 

 at apex, doubly-serrate oa margin, deep green above, pale yellowish-green below. 



LEAF-SCARS — Similar to those of the Black Birch. See page 118. 



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

 usually on the same branch. Stam.inate formed in the fall, remaining over winter as aments 

 about 3 of an inch long, usually in clusters of three, which elongate to about 2-3 inches the 

 following spring. Pistillate about 4 of an inch long, developing in spring from buds situate 

 below the staminate flowers. 



FRUIT — An erect, slender-stalked, pubescent, cylindrical strobile, 1-1* inches long, consisting 

 of numerous 3-lobed pubescent scales fastened to central axis and bearing small, hairy, winged 

 nuts. Terminal lobe of the scales is larger than the laterals. 



WOOD — Diffuse-p'orous; rays indistinct; light, soft, strong, with light-brown heartwood and 

 pale thin sapwood. Weighs 35.91 pounds per cubic foot. Used in the manufacture of 

 furniture, slack-cooperag?, fruit and vegetable baskets, wooden ware, and turnery. 



DISTINGUISHING CHARACTERISTICS— The Red Birch, also known as the River Birch, can 

 be recognized by its reddish-brown to cinnamon-red bark which peels off into film-like papery 

 scales. The layers are smaller and less ragged than those of the Yellow Birch which has 

 a decidedly yellow )r silvery-yellow colored bark. The Black Birch has a closer bark which | 

 does not peel off and the other species of Pennsylvania have a white bark. The River 

 Birch is usually found along streams or in other wet locations which may also aid in dis- 

 tinguishing it. 



RANGE — Massachusetts south to Florida, west to Minnesota, Kansas and Texas. 



DISTRIBUTION IN PENNSYLVANIA— E^ound throughout the State along the banks of the 

 principal rivers and their chief tributaries. 



HABITAT — Prefers the banks of streams, lakes, pools, and swamps. Occasionally found 

 upon drier locations. It is called River Birch because it is usually found along the banks of 

 rivers or other locations having similar moisture conditions. 



IMPORTANCE OF THE SPECIES — The Red Birch is of little commercial importance in Pennsyl- 

 vania as a lumber species on account of the relatively small size which it attains, the softness 

 of its wood, and the absence of figure and attractive color in the wood as well as its limited 

 distribution. It is essentially a southern species reaching its optimum development in North 

 Carolina and adjoining states. While it is of little commercial importance it may be of economic 

 importance in such situations where moisture-loving trees are required to bind soil, as along 

 streams, or where it is desirable to establish stands in extremely swampy locations. It is attract- 

 ive as an ornamental tree. 



