500 



SALICACEAE. 



17. Salix petiolaris J. E. Smith. 

 Slender Willow. (Fig. 1189.) 



Sal i.r petiolaris J. E. Smith, Trans. Linn. Soc. 6: 

 122. 1802. 



A shrub, similar to the preceding species, but 

 the young leaves only slightly silky, the 

 branches slender, upright or ascending. Ma- 

 ture leaves lanceolate, acuminate at both ends, 

 serrulate with blunt cartilaginous teeth, remain- 

 ing green in drying, 4 // -8 // wide; petioles i"-" 

 long; stipules deciduous; aments expanding be- 

 fore the leaves, the pistillate short-peduncled, 

 usually rather loose, about i' long in fruit; sta- 

 mens 2; filaments glabrous; stigmas nearly ses- 

 sile; capsule tapering from an ovoid or oblong 

 base, pubescent, 2 // -3 // long, about twice as 

 long as the filiform pedicel. 



In swamps, New Brunswick to the Northwest 

 Territory, south to Tennessee and Michigan. May. 

 Salix petiolaris gracilis Anders, in DC. Prodr. 16: Part 2, 235. 1868. 

 Salix- gracilis Anders. Proc. Am. Acad. 4: 67. 1858. 



Pedicels nearly as long as the capsules; leaves rather narrower. Range undetermined. 



18. Salix argyrocarpa Anders. Silver 

 Willow. (Fig. 1190.) 



.S. argyrocarpa Anders. Mon. Sal. iff/./. 60. 1867. 

 An erector diffuse shrub, 6 / -2 high, the twigs 

 dark green, nearly terete, shining. Leaves ob- 

 long or oblanceolate, acute at each end or the 

 lower obtuse, short-petioled, entire or crenu- 

 late, bright green and glabrous above, persist- 

 ently silvery-silky beneath, i / -2 / long, 3 // -6 // 

 wide, the margins slightly revolute; aments un- 

 folding with the leaves, leafy-bracted at the base, 

 dense, i' or less long; scales persistent, villous; 

 stamens 2, distinct, their filaments glabrous; 

 style slender, longer than the stigmas; capsule 

 oblong-conic, densely silver} 7 , acute, i // -i^ // 

 long, about twice as long as its pedicel. 



Labrador and Quebec to the White Mountains of 

 New Hampshire. Hybridizes with 5. phvlicifolia. 

 June-July. 



19. Salix desertorum Richards. Desert 

 Willow. (Fig. 1191.) 



Salix desertorum Richards. Frank. Jouni. App. 



371. 1823. 



A shrub, 6 / -i2 / high, with purplish-green 

 twigs. Leaves oblong or oblanceolate, acute at 

 the apex and cuneate at the base or the lower 

 obtuse at both ends, entire or very nearly so, 

 very short-petioled, tomentose on both sides or 

 glabrate above when old, ^ / -2 / long, 

 wide; stipules fugacious; aments expanding with 

 the leaves, dense, y 2 ' or less long, leafy-bracted 

 at the base; stamens 2; filaments glabrous; style 

 about as long as the deeply 2-cleft stigmas; 

 capsule ovoid-conic, acute, densely tomentose, 

 about 2 /x long, very short-pedicelled. 



Anticosti and Quebec to western arctic A:: 

 south along the Rocky Mountains to Colorado. 

 Summer. 



