152 



TREES OF NORTH AMERICA 



below the middle; ovary sessile, villose, the stigmatic lobes sessile. Fruit ovoid, acuminate, 

 glabrous. 



A shrub with stems 10 or 12 tall, or rarely a tree 25 high, with a trunk 5' or 6' in 

 diameter, thin spreading branches forming a round-topped head, and slender glabrous red- 

 brown branchlets. Bark of the trunk thin, longitudinally fissured, grayish brown. 



Fig. 146 



Distribution. Southern Alberta and valley of the Fraser River (Clinton), British Colum- 

 bia, southward through western Washington and Oregon to San Diego County, California, 

 and southeastern Nevada, and eastward to southern Idaho, central Nevada and western 

 Wyoming (Yellowstone National Park). 



Apparently only truly a tree on the banks of the Palouse and other streams of eastern 

 Washington. 



Several shrubby forms of S. exigua found in Nevada, Arizona, Colorado, western Ne- 

 braska and in Lower California are distinguished. 



13. Salix longifolia Muehl. Sand Bar Willow. 



Salix fluviatalis Sarg. not Nutt. 



Leaves linear-lanceolate, often somewhat falcate, gradually narrowed at the ends, long- 

 pointed, dentate with small remote spreading callous glandular teeth, 2'-6' long, \'~\' 

 wide, when they unfold coated below with soft lustrous silky hairs, at maturity thin, gla- 

 brous, light yellow-green, darker on the upper than on the lower surface, with a yellow mid- 

 rib, slender arcuate primary veins, and slender reticulate veinlets; petioles grooved, f'-y' 

 long; stipules ovate-lanceolate, foliaceous, about \' long, deciduous Flowers: aments 

 cylindric on leafy branchlets, pubescent, the stamina te about 1' long, \' broad, terminal and 

 axillary, the pistillate elongated, 2' or 3' long, about \' broad; scales obovate-oblong, en- 

 tire, erose or dentate above the middle, light yellow-green, densely villose on the outer 

 surface, slightly hairy on the inner; stamens 2, with free filaments slightly hairy at the base; 

 ovary oblong-cylindric, acute, short-stalked, glabrous or pubescent, with large sessile 

 deeply lobed stigmas. Fruit light brown, glabrous or villose, about \' long. 



A tree, usually about 20 high, with a trunk only a few inches in diameter, spreading 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 sea- 

 son; occasionally 60-70 high, with a trunk 2 in diameter; often a shrub not more than 

 5-6 tall. Winter-buds narrowly ovoid, acute, chestnut-brown, about \' long. Bark 



