176 



TREES OF NORTH AMERICA 



ing by stoloniferous roots into broad thickets, short slender erect branches, and 

 slender glabrous light or dark orange-colored or purplish red branchlets, growing 

 darker after their first season; occasionally 60-70" high, with a trunk 2 in diame- 

 ter; often a shrub not more than 5-6 tall. "Winter-buds narrowly ovate, acute, 

 chestnut-brown, about ^' long. Bark ^'-\' thick, smooth, dark brown slightly tinged 

 with red and covered with small closely appressed irregularly shaped scales. Wood 

 light, soft, light brown tinged with red, with thin light brown sapwood. 



Distribution. River banks and sand-bars; shores of Lake St. John and the Island 

 of Orleans in the Province of Quebec, southward through western New England to the 

 valley of the Potomac River, northwestward to within the Arctic Circle in the valley of 

 the Mackenzie River and to British Columbia and California, and southward through 

 the basin of the Mississippi River to northern Mexico and Lower California; exceed- 

 ingly common in the valley of the Mississippi, attaining its largest size in southern 

 Indiana and Illinois and in southern Arkansas; gradually becoming smaller and less 

 common toward the Atlantic seaboard; abundant in all the prairie region of British 

 America and lining the banks of streams flowing eastward through the central plateau 

 of the continent, where it is the commonest Willow; common in Texas west of the 



valley of the Pecos River; rare in New Mexico and Arizona south of the Colorado 

 plateau; common in the region adjacent to the Pacific coast from Lower California 

 to northern British Columbia. From western Texas to northern California often 

 replaced by the var. argyrophylla, Sarg., with leaves and capsules covered with silky 

 pale tomentum, and by the var. exigua, Sarg., with very short linear leaves. 



9. Salix sessilifolia, Nutt. Willow. 



Leaves involute in the bud, lanceolate or linear-lanceolate, often slightly falcate, 

 narrowed at the ends, long-pointed at the apex, entire or dentate above the mid- 

 dle, covered as they unfold with hoary tomentum, at maturity light yellow-green, 

 glabrous or puberulous above, villous below, with silky lustrous white hairs, l^'-5' 

 long, j-^'-^ wide, with yellow midribs and obscure arcuate veins; their petioles stout, 

 pubescent, rarely more than ^ ^^ng; stipules acute, hoary pubescent, about ^ long, 

 deciduous. Flowers: aments cylindrical, densely flowered, terminal and axillary on 

 leafy branches, 3' long on the pistillate plant, not more than one half as long and 



