THE GYMNOSPERM TREES 259 



pine leaves are four to six inches long, while those of the jack 

 pine are only about an inch long. The eastern white, western 

 white, and sugar pines all have their needles in fives, but their 

 botanical ranges do not overlap, and they possess differences 

 in length of cones and height of growth. 



The EASTERN WHITE PINE referred to above has aided man 

 immeasurably in the development of the United States. For 

 almost three hundred years it was the principal species cut for 



Fig. 181. — Pines have needle-like leaves in clusters; the white pine (A) 

 has five needles in a cluster, the red pine (B) has two, and the pitch pine (C) has 

 three. 



lumber, and its sudden decline in the last fifty years is due princi- 

 pally to exhaustion of the once plentiful supply. It is the largest 

 of the eastern conifers, commonly growing to a hundred feet in 

 height and sometimes exceeding two hundred. Its best growth is 

 made on moist sandy loam soils, although the tree will tolerate 

 a wide variety of soil conditions. Its wood is soft and extremely 

 even grained, due to the gradual transition from spring to sum- 

 mer wood. Because of its ease of propagation in the nursery, and 

 its very rapid growth — as much as four feet per year under very 

 favorable conditions — white pine has been widely used as a tree 

 for planting in reforestation. However, a fungus disease, the 



