BETULA POPULIFOLIA, MARSH. 67 



South, mostly in the coast region, to Delaware ; west to Lake 

 Ontario. 



Habit. A small tree, 20-35 feet high, with a diameter at 

 the ground of 4-8 inches, occasionally much exceeding these 

 dimensions ; under favorable conditions, of extreme elegance. 

 The slender, seldom erect trunk, continuous to the top of the 

 tree, throws out numerous short, unequal branches, which form 

 by repeated subdivisions a profuse, slender spray, disposed 

 irregularly in tufts or masses, branches and branchlets often 

 hanging vertically or drooping at' the ends. Conspicuous in 

 winter by the airy lightness of the narrow open head and by 

 the contrast of the white trunk with the dark spray ; in 

 summer, when the sun shines and the air stirs, by the delicacy, 

 tremulous movement, and brilliancy of the foliage. 



Bark. Trunk grayish-white, w T ith triangular, dusty patches 

 below the insertion of the branches ; not easily separable into 

 layers; branches dark brown or blackish; season's shoots 

 brown, with numerous small round dots becoming horizontal 

 lines and increasing in length with the age of the tree. 'The 

 white of the bark does not readily come off upon clothing. 



Winter Buds and Leaves. Buds somewhat diverging from 

 the twig ; narrow conical or cylindrical, reddish-brown. 

 Leaves simple, alternate, single or in pairs, 3-4 inches long, 

 two-thirds as wide, bright green above, paler beneath, smooth 

 and shining on both sides, turning to a pale shining yellow 

 in autumn, resinous, glandular-dotted when young ; outline 

 triangular, coarsely and irregularly doubly serrate ; apex 

 taper-pointed ; base truncate, heart-shaped, or acute ; leaf- 

 stalks long and slender ; stipules dropping early. 



Inflorescence. May . Sterile catkins usually solitary or 

 in pairs, slender-cylindrical, 2-3 inches long : fertile catkins 

 erect, green, stalked ; bracts minutely pubescent. 



Fruit, Fruiting catkins erect or spreading, cylindrical, 

 about 1J inches long and ^ inch in diameter, stalked; scales 

 3-parted above the center, side lobes larger, at right angles or 

 reflexed : nuts small, ovate to obovate, narrower than the 

 wing's, combined wings from broadly obcordate to butterfly - 

 shape, wider than long. 



