158 



TREES OF NORTH AMERICA 



ning obliquely almost to the margins, and slender terete petioles 1^' long, abruptly 

 enlarged at the base. Flowers: aments long-stalked, the pistillate becoming 4'-5' 

 long before the fruit ripens, their scales broadly obovate, light brown and scarious, 

 often irregularly 3-parted at the apex, cut into short thread-like brown lobes; disk 

 of the staminate flower oblique, short-stalked; stamens 20-30, with short filaments 

 and large light red anthers; disk of the pistillate flower cup-shaped; ovary ovate, 

 slightly 2-lobed, with 2 nearly sessile large oblique dilated crenulate stigmas. Fruit 

 ovate-oblong, acute and often curved at the apex, 2-valved, light brown, about \' 

 long, raised on a slender stalk y^'-^' long; seeds oblong-obovate, pointed at the 

 apex, narrowed and truncate at the base, light brown, about ^' long. 



A tree, often 100 high, with a tall trunk 6-7 in diameter, stout erect branches 

 usually more or less contorted near the ends, forming a comparatively narrow 

 open head, and branchlets marked by oblong bright orange-colored lenticels, much 



roughened by the thickened leaf-scars, at first red-brown and glabrous or pubescent, 

 becoming bright and lustrous in their first winter, dark orange-colored in their 

 second year, and finally gray tinged with yellow-green ; usually much smaller toward 

 the southern limits of its range. Winter-buds saturated with a yellow balsamic 

 sticky exudation, ovate, terete, long-pointed, terminal 1' long and ^ broad; axillary 

 about 1^' long, ^ig' broad, with 5 oblong pointed concave closely imbricated thick 

 chestnut-brown lustrous scales. Bark light brown tinged with red, smooth or 

 roughened by dark excrescences, becoming on old trunks f -1' thick, gray tinged 

 with red, and divided into broad rounded ridges covered by small closely appressed 

 scales. Wood light brown, with thick nearly white sapwood. 



Distribution. Low often inundated river-bottom lands and swamp borders; 

 Labrador to latitude 65 north in the valley of the Mackenzie River, and to the Alas- 

 kan coast, south to northern New P^ngland and New York, central Michigan and Min- 

 nesota, the Black Hills of Dakota, northwestern Nebraska, northern Montana, Idaho, 

 Oregon, and Nevada; the characteristic tree on the streams of the prairie region 

 of British America, attaining its greatest size on the islands and banks of the Peace, 

 Athabasca, and other tributaries of the Mackenzie; common in all the region near 

 the northern boundary of the United States from Maine to the western limits of the 

 Atlantic forests; the largest of the sub-Arctic American trees, and in the far north 

 the most conspicuous feature of vegetation. 



Often planted at the north for shelter or ornament. 



