50 Bulletin 73 



Willows are coininonly introduced a8 shade trees because they are so 

 easily prop:^gated by cuttings. Care should be taken, however, to select 

 the stamen-bearing trees, both because these are more ornamental when in 

 flower and because they do not produce the downy fruit which is often dis- 

 agreeable when they are growing near houses. 



The following key, while not entirely satisfactory, may aid in recog- 

 nizing the three tree willows. 



Smaller, slender, native trees, bark rough, twigs dark Black Willow 



Larger, spreading, introduced trees. 



Twigs yellow, young leaves ashy-gray or silver-white on both sides White Willow 



Twigs blue-green, young leaves green above, paler beneath Crack Willow 



BLACK WILLOW. SaUx nigra Marsh. 



The black willow is a slender, rather 

 graceful tree, common everywhere, along the 

 banks of lakes and streams. It may usually 

 be recognized by its stouter dark brown or 

 black twigs in contrast with the more slender, 

 yellowish or bluish-green twigs of the European 

 species. When the pendulous catkins open, 

 three, five or more stamens may be found in 

 each tiny flower. The leaves are green wlien 

 mature and smooth except on the mid-veins 

 and petioles. 



BLACK WILLOW 



Leaf and flowers, starainate 

 above, pistillate below, X H- 



WHITE WILLOW (yellow WILLOW ). Salix olhci 



vitelUna Koch. 



The white willow was introduced from 

 Europe, but it has been so commonly planted 

 and is so frequently spontaneous 

 along the banks of streams and 

 lakes, that it merits a place in this 

 list. If one observes closely the 

 tiny staminate flowers in May 

 both this and the next species are 

 clearly distinguished from the 

 black willow since there are but 

 two stamens in each flower, where- 

 as the black willow has from three 

 to six. Usually, however, *one 

 must depend upon other and less 

 definite characterr--. A little prac- 

 tice, following the suggestions giv- 



WHITE WILLOW 

 Leaves and pistillate flower, x J4. 



