196 



The Willows 



Rowlee, of the eastern part of the country, and takes its place in the West. While 

 usually a mere shrub not over 2 meters high, it occasionally forms a tree in the 

 Southwest, reaching a height of 7 meters or more. 



It differs from the Siindbar willow in usually having smaller leaves with much 

 less prominent teeth, often, indeed, nearly entire-margined, and the silky hairs 

 which cover them and the twigs in the young stages are usually retained much later 

 in the season, sometimes until the leaves are quite mature. The catkins, flowers, 

 and capsules are very similar indeed to those of its eastern relative. 



16. SILVER-LEAVED WILLOW — Salix sessilifoUa Nuttall 



Salix argophylla Nuttall. Salix fluviatilis argophylla Sargent 



This is another close relative of the Sandbar willow and of the Slender willow; 

 it inhabits much the same range as the latter, being known along rivers and streams 



from Montana to Washington, Colo- 

 rado, New Mexico, and California. 

 Like the two related species it is 

 usually shrubby, but it occasionally 

 becomes a small tree, up to 10 m. 

 high, with a trunk 3 dm. thitk. 



It differs from both in having 

 leaves silvery-silky on both sides, 

 even when mature; otherwise they 

 are Uke those of the Slender wiUow, 

 being often entire-margined or nearly 

 so, and the capsules are silky, even 

 when lipe; there appear to be inter- 

 mediate forms, which have only 

 slightly silky capsules, however, 

 which may connect the two. The 

 Califomian Saiix Hindsiana Ben- 



FiG. 156. — Silver-leaved Willow. 



tham ft doubtfully distinct from it. 



The wood is soft and weak, reddish, with a specific gravity of 0.44, and is used 

 in the Northwest for basketry. 



17. MACKENZIE'S WILLOW — Salix Mackenzieana Barrett 



Salix cordata Mackenzieana Hooker 



Mackenzie's willow occurs on the shores of lakes and streams from Manitoba 

 to Idaho and California. It is a small tree, becoming as much as 9 meters high, 

 often shrubby, however, and of close aflSnity to the widely distributed shrub Salix 

 cordata Muhlenberg. 



Its bark is brown, nearly smooth, the young twigs smooth or very nearly so, 



