The Trkes of Vermont 105 



BETULACEAE 



Paper Birch. Canoe Birch. White Birch 

 Betula alba papyrifera (Marsh.) Spach. [Betula papyrifera 



Marsh.] 



Habit. — A tree 50-75 feet high, with a trunk diameter of 1-3 feet, 

 forming in youth a compact, pyramidal crown of many slender 

 hranches, becoming in old age a long, branchless trunk with a broad, 

 open crown, composed of a few large limbs ascending at an acute 

 angle, with almost horizontal branches and a slender, flexible spray. 



Leaves.- — Alternate, simple, 2-3 inches long, 1^-2 inches broad; 

 ovate ; coarsely, more or less doubly serrate ; thick and firm ; glabrous, 

 dark green above, lighter beneath, covered with minute black glands ; 

 petioles stout, yellow, glandular, glabrous or pubescent. 



Flowers. — April-May, before the leaves ; monoecious ; the stam- 

 inate catkins clustered or in pairs, 3-4 inches long, slender, pendent, 

 brownish; the pistillate catkins about 1^ inches long, slender, erect or 

 spreading, greenish ; styles bright red. 



Fruit. — Ripens in autumn ; long-stalked, cylindrical, glabrous, 

 drooping strobiles, about ly^ inches long; scales hairy on the margin; 

 nut narrower than its wing. 



Winter-buds. — Terminal bud absent ; lateral buds ^ inch long, 

 narrow-ovoid, acute, flattish, slightly resinous, usually divergent. 



Bark. — Twigs dull red, becoming lustrous, orange-brown ; bark 

 of trunk and large limbs cream-white and lustrous on the outer surface, 

 bright orange on the inner, separating freely into thin, papery layers, 

 becoming furrowed and almost black near the ground. Plate III. 



Wood. — Light, hard, strong, tough, very close-grained, light brown 

 tinged with red, with thick, whitish sapwood. 



Distribution. — Common throughout Vermont. 



Habitat. — Prefers rich, moist hillsides ; borders of streams, lakes 

 and swamps ; mountain slopes. 



Notes. — The paper birch is often intermingled with the white birch 

 and is confused popularly with it, although careful observation reveals 

 many characteristics by which the two may be distinguished. The 

 paper birch is a larger tree than the white birch and more widely 

 distributed. The two species are similar in the chalky whiteness of 

 the bark, but that of the white birch clings closely so that it cannot be 

 separated in large layers, whereas the peculiar character of the paper 

 birch is the ease with which ample sheets of the beautiful corky layers 

 may be removed. 



