4 BULLETIN" 139, U. S. DEPARTMENT OF AGRICULTURE. 



virgin stands are first cut off, these sands may grow crops for a few 

 years until the humus is exhausted. After that the necessity for 

 expensive fertilizers makes agriculture unprofitable except with 

 extraordinary market conditions. 



Norway pine is rarely found in hilly country or in swamps, except in 

 Cook County, Minn., where it occurs on some high ridges. It is com- 

 mon along lake shores. 



GROSS BOTANICAL CHARACTERISTICS. 



Norway pine belongs to the two-needled group of pines, the needles 

 themselves being from 5 to 7 inches long. The bark of young trees 

 is thin, dark, and scaly; that of mature trees is moderately thin, gray- 

 ish yellow or reddish brown, in diamond-shaped plates. Owing to 

 the characteristic appearance of the bark and the relatively high spe- 

 cific gravity of the wood of young trees, the latter are often locally 

 distinguished as "pig iron" and "shellbark Norway." The cones, 

 some 2 inches long, are brown and brownish yellow when mature. 

 The brownish buds have rolled-back scales; the seed is held as with 

 forceps and has fight wings. 



HABIT AND ROOT SYSTEM. 



The bole of Norway pine is normally slender, straight, or in old age 

 slightly bending, with but little taper. It is unusual to find a forest- 

 grown tree with a decidedly crooked, misshapen bole. The difference 

 between the straight, symmetrical bole of young red pine and the fre- 

 quently misshapen one of white pine, the result of weevil damage, is 

 strikingly apparent. The large tufted clumps of long needles give 

 the crown an open appearance, in contrast to the denser crown and 

 more delicate needles of white pine and the ragged, narrow crown of 

 jack pine. The branches are in distinct whorls. In old age the crown 

 becomes short and irregular. Seedlings during the first summer 

 develop a taproot from 6 to 18 inches long. The sapling, therefore, 

 has a strong taproot, which gives place to to stout laterals as the tree 

 matures. Except when overmature and declining in vigor, Norway 

 pine is remarkably windfirm. 



SIZE AND LONGEVITY. 



Norway pine rarely reaches a diameter of more than 33 inches 

 breast high. The largest tree of which there is a reliable record meas- 

 ured 60 inches in diameter outside the bark. On the Minnesota 

 National Forest the average run of 16-foot logs cut from a stand 

 mostly over 200 years old scaled 15 to the thousand board feet. The 

 average run of mature Norway pine in mixture with hardwoods, or 

 with white pine on the better soils, is perhaps from 11 to 13 logs to 



