Trees of New York ^Slalc 103 



BETULACEAE 



Bctula liitfu jMichx. f. 



Yellow Birch, Gray Birch 



Habit — A tree at maturity usually GO-75 feet in heiglit with trunk dianieter 

 of 2-3 feet, sometimes' 100 feet tall and 3-5 feet through. In the open 

 the crown is broadly ovoid, consisting of long, wide-spreading, somewhat 

 pendidous branches borne aloft on a short bole which is continuous into 

 the crown or l)roaks up a short distance above tlie ground into several 

 large, ascending limbs. Under forest conditions the bole is usually clean 

 for some distance below. 



Leaves — Alternate, ovate, oblong-ovate or elliptical, 3-4i^ inches long, l%-2 

 inches wide, acute at the apex, rounded or slightly heart-shaped and 

 inequilateral at the base, sharply doubly serrate, at maturity smooth, 

 dull and dark green above, pale yellowish green and hairy at least on 

 the veins below, borne on slender, pale yellow, hairy, terete jjetioles %-l 

 inch long. 



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

 Itorne in aments. Staminate aments preformed the preceding season, clus- 

 tered, subterminal, cylindrical, at anthesis bro\vnish yellow, 3-3 1/^ inches 

 long. Pistillate aments appearing as the buds unfold, terminal and soli- 

 tary on sliort, 2-leaved lateral branches, pale green, oblong-cylindrical^ 

 nearly sessile, about % of an inch long. Flowers borne in clusters of 3. 

 The staminate flowers consist of 4 yellow half-anthers raised on short, 

 bifurcated filaments and accompanied by a calyx of 1 sejjal, the cluster 

 of 3 covered distally by a peltate broadly oval bract and 2 bracteoles. 

 The pistillate flower consists of a small, green, ovoid ovary surmounted 

 by 2 spreading, filiform styles, the cluster of 3 subtended by an oblong, 

 obtuse bract and 2 adnate bracteoles. 



Fruit- — ^ An erect, sessile or nearly sessile, pale brown, oblong-ovoid, woody 

 strobile, l-l^^ inches long and about % of an inch wide, consisting of 

 imbricated, 3-lobed bracts which are puberulous on the back and subtend 

 winged nutlets, both deciduous in the autumn from the slender rachis. 

 Nutlets compressed, ovate to oval, cllestuut-bro^^^l, aVjout % of an inch 

 long, crowned by the 2 persistent styles, with lateral marginal wings 

 narrower than the nutlet. 



Winter characters — Twigs slender, lenticellate, smooth, light yellowish 

 brown, becoming dark brown and lustrous and finally dull silvery-gray, 

 with faint wintergrcen odor when chewed. Short, spur-like, lateral fruit- 

 ing branches present. Buds narrowly ovate, acute, lustrous, somewhat 

 divergent, chestnut-brown, about % of an inch long, covered by 3—8 scales 

 downy on the margins. Staminate aments grouped at the tips of vigorous 

 twigs, oblong-cylindric, light chestnut-brown and lustrous, %-l inch long. 

 Bark on young trunks or limbs lustrous, close and firm, bright silvery- 

 gray, separating at the surface into thin, revolute, clinging scales. 

 Mature bark reddish brown to nearly black, broken into large, thick, 

 irregular plates. 



Habitat — Eich moist uplands in company with Beech, Sugar Maple, Ash, 

 Hornbeam, Hemlock, Red Spruce, etc. 



Range — Newfoundland soutli along the mountains to North Carolina and 

 Tennessee, west through southern Ontario, Michigan and Wisconsin to 

 Minnesota. Zones B, C, D, and E. 



Uses — Wood heavj', hard, strong, close-grained, light reddish brown with 

 thin, nearly white sapwood. Used for furniture, flooring, interior finish, 

 agricultural implements, turnery, and for fuel. 



