WILLOWS : THEIR GROWTH, USE, AND IMPORTANCE. 5 



There are several forms of the white willow, one of which, the yellow 

 willow (Salix alba vitellina), is as common as the white willow. The 

 bright yellow bark of this variety and its greater inclination to 

 branchiness readily distinguish it. 



The white willow has pale-green leaves with silky pubescence on 

 both sides, but at maturity the upper surface is nearly smooth. 

 The edges are finely toothed. The mature leaves are from 2 to 4J 

 inches long and from one-third to two-fifths of an inch wide. The 

 bark is from half an inch to 1^ inches thick on large trees, dark 

 brown on the trunk with a reddish tinge higher up. It is deeply 

 divided into broad, flat connecting ridges. Green, yellow, and red 

 twigged forms are known to the trade. 



CRACK WILLOW. 



(Salix fragilis L.) 



The crack willow, or gray willow, as it is often called, is quite 

 similar in general appearance to the white willow. Under the same 

 conditions it easily reaches the size attained by the white willow, 

 but is in general a more slender and better formed tree. It is easily 

 distinguished from the white willow by its larger, coarsely notched 

 leaves and by its reddish-green twigs, which are extremely brittle 

 at the base. The leaves are from half an inch to 1 inch wide, nar- 

 rowed at the base, and from 3 to 6 inches long. At maturity they 

 are smooth on both sides, dark green above and paler beneath. 

 The bark is smooth and green on the upper portions of the tree. 

 On the lower trunk it is rough, scaly, ridged, gray-brown, and 1 

 inch to 1£ inches thick. The crack willow does not produce so 

 many water sprouts along the trunk as the white willow and there- 

 fore makes cleaner timber. It is undoubtedly the best willow 

 species for plantations in the Prairie States. Many of the so-called 

 white willow plantations are really crack willow. It is commonly 

 planted in eastern, central, and northern United States. A yellow 

 form is occasionally found in the nursery trade. 



WEEPING WILLOW. 



(Salir. bahylonica L.) 



The weeping willow is another of the introduced species that is 

 now widely scattered over the United States. Though a rapid 

 grower at first, it does not reach the size attained by the white and 

 crack willows. The height is seldom over 50 feet, but may occasion- 

 ally read] 80 feet. The diameter is often from 3 to 5 feet when the 

 tree i- grown in the open. The weeping willow can readily be dis- 

 tinguished from 1 he white willow, which it most closely resembles, by 



