ROWLEE : NORTH AMERICAN WILLOWS 255 



COLORADO (Hall and Harbour, no. 132) (Brandegee). 



NEW MEXICO : Pecos River, San Miguel Co. (A. A. & E. G. 

 Heller, no. 3684) ; North American Pacific Coast Flora, etc. (C. 

 C. Parry, no. 306). 



10. SALIX EXIGUA Nuttall N. Am. Sylva, i : 75. 1842 



Salix Nevadensis Watson, Am. Nat. 7 : 302. 1873. 



Variable in stature from a low slender shrub to a small tree : 

 branches light brown, leaves 4 cm. by 1-2 cm., yellowish, closely 

 sessile, opaque, entirely or nearly so, canescent when young, usu- 

 ally becoming quite glabrous at maturity, very narrowly elliptical, 

 veins very indistinct, stipules none : aments 2-5 cm. long on pe- 

 duncles about the same length, appearing with the leaves, rather 

 densely and evenly flowered, sometimes the lower flowers remote, 

 scales in the staminate ament oblong to obovate, in the pistillate 

 narrower and longer, smooth or more or less crisp villous on the 

 margins : capsule closely sessile, lanceolate, glabrous, light green : 

 stigmas short and thick, sessile, sometimes even appearing slightly 

 sunken in the apex of the capsule. 



Readily distinguished from related species by its entire opaque 

 leaves and glabrous capsules. 



Salix exigua virens var. nov. 



Leaves large, 10-12 cm. long, i cm. wide, nearly glabrous, veins 

 conspicuous on both sides, distinctly denticulate : stipules large, 

 oblong denticulate : aments large, the pistillate 4 cm. long, i cm. 

 thick, sometimes borne in threes at the ends of the long leafy 

 shoots. 



Easily distinguished from the type by the size and texture of 

 the leaves and the presence of stipules. 



Salix exigua occurs throughout the Rocky Mountain region 

 of the United States, but has not yet been reported from British 

 America or Mexico. It seems probable, however, that it will be 

 found both north ancj south of the range indicated. Prof. Aven 

 Nelson observes that in Wyoming this species grows on positively 

 the " worst alkali soil that can be imagined, where it is small, 

 slender, and twig-like, but of dense growth." 



CALIFORNIA : Surprise Canon and Hot Springs, Inyo Co. (F. 

 V. Coville and F. Funston, nos. 722 and 68 1), San Bernardino 

 (W. G. Wright, no. 2), Cashewberry Springs, Mohave Desert (S. B. 



