204 



TREES OF NORTH AMERICA 



bags, drink ing-cups, and other small articles, and often to cover their wigwams in 

 winter. 



Distribution. Rich wooded slopes and the borders of streams, lakes, and swamps, 

 scattered through forests of other trees; Labrador to the southern shores of Hud- 

 son's Bay and Great Slave Lake, and southward to Long Island, New York, north- 

 ern Pennsylvania, central Michigan, central Iowa, northern Nebraska, the Black 

 Hills of Dakota, northern Montana and northwestern Washington; common in the 

 maritime provinces of Canada and north of the Great Lakes, and in northern New 

 England and New York; small and comparatively rare in the coast region of south- 

 ern New England and southward; not common in the Rocky Mountain region; on 

 the highest mountains of New England the var. cordifolia (Fig. 170) is common as 

 a small tree or shrub, and also occurs northward and on the Rocky Mountains. 



Often planted in the northeastern states as an ornamental tree. 



7. Betula occidentalis, Hook. Birch. 



Leaves ovate, acute, usually rounded, occasionally cordate or rarely cuueate at 

 the broad base, coarsely and generally doubly serrate, with straight or incurved 

 glandular teeth, while young light yellow-green, covered with dark reddish resinous 

 viscid glands, and villous along the midribs and veins, with long white hairs often 

 also in large persistent tufts in the axils of the primary veins, and at maturity thin 

 and firm in texture, marked by the scars of the fallen glands, dull dark green above, 

 pale yellow-green below, and puberulous on both sides of the stout yellow midribs 

 and slender primary veins, 3'-4' long, l'-2' wide ; their petioles stout, glandular, at 

 first tomeutose, ultimately pubescent or puberulous, about f ' long ; stipules oblong- 

 obovate, rounded or acute and apiculate at the apex, ciliate on the margins, puber- 

 ulous, glandular-viscid, about ^' long, \'-\' wide. Flowers: staminate aments dur- 

 ing the winter about ' long and \' thick, with ovate scales rounded or abruptly 



narrowed and acute at the apex, puberulous on the outer surface, ciliate on the 

 margins, becoming 3'-4' long and about \' wide ; pistillate aments about 1' long 

 and ^y thick, with acuminate bright green scales. Fruit : strobiles cylindrical, pu- 

 berulous, spreading, l^'-l^' long, \'-% thick, on stout peduncles ' in length, their 

 scales ciliate on the margins ; nut oval, about ^' long, and nearly as wide as its wings. 



