THE WILLOW. 



243 



most species it is stringy and unusually tough, 

 and in all is of a bitter taste, owing to the presence 

 of a chemical principle called salicine, which pos- 

 sesses nearly the same medicinal properties as 

 quinine, the substance which is extracted from 

 Peruvian bark. The leaves are undivided, either 

 notched at the edges, or even, stalked, often fur- 



BLOSSOM OF THE CRACK WILLOW. 



nished with stipules, smooth or silky, downy, or 

 even cottony, and varying in shape from linear 

 to round, some modification of the ellipse being, 

 however, by far the commonest form. The flowers, 

 which are catkins, appear early, and are of two 

 kinds, each growing on a separate tree. The bar- 

 ren catkin, is an erect stem, closely invested on all 

 sides with leafy over-lapping scales, within each 



