It is now naturalized from the St. Lawrence Valley to the Potomac 

 River and westward. The tree occurs singly and in groups along the 

 banks of streams and on moist bottom lands. It is never the pre- 

 dominating species. 



It has been planted and successfully grown over a large area, ex- 

 tending through the Northern States, south to Virginia, Kentucky, 

 and Tennessee, and west to Missouri, Kansas, Colorado, and the 

 Dakotas. 



HABITS AND GROWTH. 



The white willow prefers q, moist, rich, sandy loam of alluvial 

 origin. Throughout its natural range the tree attains its best devel- 

 opment and is most frequently found on low, moist ground along the 

 banks of streams. It would undoubtedly spread to the uplands were 

 it not for the fact that the seeds invariably fail to germinate when 

 lodged on high and dry situations. It is sufficiently hardy to grow 

 on the dry prairies of the Dakotas, but its growth on upland situa- 

 tions is considerably slower than when planted in the bottom lands. 

 Although a light-demanding tree, it forms a dense canopy when 

 close planted. 



The rate of growth is largely dependent upon site conditions. On 

 low, moist soil an annual height growth of 3 feet with a diameter 

 increase of 1 inch is not unusual, while on upland situations a yearly 

 increase of from 1J to 2 feet in height and from one-half to three- 

 fourths inch in diameter is all that may be expected. 



With the exception of the oaks, the willow is said to be infested with 

 more insects than any other tree in North America. Most of these 

 are leaf-eating insects, but there are also borers, gall producers, and 

 scales. Should insects appear in alarming numbers, specimens, ac- 

 companied by a full description of their work, should be sent to the 

 Bureau of Entomology, Department of Agriculture, for identification 

 and information in regard to methods of control. The principal 

 insects which affect willow are considered in an article, by Dr. F. H. 

 Chittenden, in Bulletin No. 46 of the Bureau of Forestry, pages 

 .63-80. 



Willows are subject to a number of fungous diseases. Those of 

 economic importance are " rust " and the " red rot." A mildew 

 sometimes covers the leaves late in the season with a white web. In 

 the spring and early fall small branches are often covered with a 

 fungus, the spores of which will blacken the hand of a person break- 

 ing off one of the infected branches. When fungi are believed to 

 be present, specimens should be sent to the Bureau of Plant Industry, 

 Department of Agriculture, where examinations are made and meth- 

 ods of treatment suggested. 



[Cir. 87] 



