Issued January 19, 1907. 



United States Department of Agriculture, 



FOREST SERVICE— Circular 72. 



GIFFORD PINCHOT, Forester. 



FOREST PLANTING LEAFLET. 



WESTERN YELLOW PINE (Pinus ponderosa) . 



FORM AND SIZE. 



The western yellow pine is one of the largest and most valuable of 

 the pines. It ranges in size from not more than 60 feet high in the 

 arid portions of its range to 200 feet in height and 6 feet in diameter 

 on the western slopes of the Sierras. It has a straight and sym- 

 metrical stem and usually a long, spire-like crown, which, even in 

 fairly dense stands, covers from one-half to one-third of the tree. 

 The needles are from 6 to 10 inches long and usually grow in bundles 

 of three. 



RANGE. 



The natural range of western yellow pine is throughout the United 

 States west of the one hundredth meridian. It is most common in 

 the Rocky Mountain and Pacific Coast ranges at medium altitudes. 



The tree may be planted anywhere within its natural range and, in 

 favorable situations, several degrees farther east. It is particularly 

 well suited for planting in the sand-hill regions of western Nebraska 

 and Kansas and on denuded watersheds in the Rocky Mountains and 

 Pacific Coast regions below an elevation of 6,000 feet. 



SILVICAL QUALITIES. 



I 



Western yellow pine is a very hardy tree and will endure great 

 diversities of soil and climate. It is especially suitable for planting 

 in dry regions where droughts are not too prolonged. 



The conditions under which it usually grows prevent the tree from 

 making a rapid growth. In the most favorable situations, however, 

 its growth is fairly rapid. 



Western yellow pine has suffered greatly from the attacks of bark 

 beetles. The trees are usually attacked during August and Septem- 

 ber and die by the following spring. If a plantation is attacked by 

 these insects, specimens, with description of the damage, should be 

 sent to the Bureau of Entomology, Department of Agriculture. 



Because of their long and heavy foliage, the young trees are some- 

 times borne down by deep snows. 

 17073— No. 72—07 m 



