﻿Trees of New York State 167 



BETULACEAE 



Betula populifolia Marsh. 



Gray Birch, Old Field Birch, White Birch 



Habit — A small tree 20-35 feet high, with a trunk diameter of 6-12 inches, 

 occasionally 50 feet tall with a diameter of 18 inches. The boles usually 

 arise in groups of 2-6 from a common root-crown. Crown open, rather 

 irregular, narrowly pyramidal, often extending to the ground, consisting 

 of slender, ascending or horizontal branches and drooping branchlets. 

 Bole continuous to the top of the crown. 



Leaves — Alternate, triangular to rhombic-ovute, 214-3 inches long, 11^-21^ 

 inches wide, long attenuate at the apex, cuneate or truncate at the base, 

 coarsely doubly serrate^ at maturity thin but firm in texture, dark green, 

 lustrous and somewhat glandular above, pale green and glabrous or hairy 

 on the veins below, borne on long, black-glandular, terete petioles. 



Flowers — 'Appearing in late March or April with the leaves, monoecious, 

 borne in aments. Staminate aments preformed the previous season, usu- 

 ally solitain-, subterminal. narrowly cylindrical, at anthesis brownish yel- 

 low, 2^4-4 inches long. Pistillate aments appearing as the buds unfold, 

 terminal and solitary on short, 2-leaved lateral branches, pale green, 

 linear-cylindical, pedunculate, ^/^-l inch long. Flowers borne in clusters 

 of 3. The stiimiuate flowers consist of 4 yellow half-anthers raised on 

 short bifurcated filameuts and accompanied by a calyx of 1 sepal, the 

 cluster of 3 covered distally by a peltate, obovate bract and 2 bracteoles. 

 Pistillate flowers consisting of a small, green, ovoid ovary crowned by 2 

 spreading, filiform, pale red styles, the cluster of 3 subtended by an ob- 

 long, obtuse bract and 2 adnate bracteoles. 



Fruit — A pedunculate, pale brown, cylindrical, obtuse, woody strobile, about 

 % of an inch long and ^4 of an inch wide, consisting of puberulous, imbri- 

 cated, 3-lobed bracts subtending winged nutlets, both deciduous in the 

 autumn from the slender rachis. Nutlets compressed, oval-obovate, chest- 

 nut-brown, 1/16-1/12 of an inch long, croA^nied by the 2 persistent styles, 

 with lateral marginal wings broader than the nut. 



Winter characters — Twigs slender, lenticellate, lustrous, roughened by warty 

 glands, reddish broAvn or nearly Avhite near the trunk. Buds ovate, acute, 

 smooth, somewhat resinous and divergent, covered by 3-4 scales downy at 

 the margins. Staminate aments usually solitary, subterminal, linear- 

 cylindrical, 11/4-11/4 inches long. Mature bark thin, close, dull grayish 

 white with bright orange inner bark, nearly black and fissured at the base 

 of the tree. 



Habitat ^ — -A short-lived "weed" tree establishing itself rapidly in abandoned 

 fields, burns and on waste lands. Thrives on moist soil along streams and 

 lakes. 



liange — Nova Scotia, south to Delaware and southern Pennsylvania, west- 

 ward to Central Quebec, southern Ontario, and western New York. Zones 

 A, B, C, and D. 



Uses — Not an important timber species. Grown ornamentally. Wood light, 

 soft, weak, close-grained, pale brown with thick, nearly white sapwood. 

 Used largely for fuel, also for spools, shoe pegs, etc. 



