EVERGREENS OF COLORADO 



21 



BLUE SPRUCE, COLORADO BLUE 

 SPRUCE, SILVER SPRUCE. 



Picca parry ana (Andree) Sarg. 



This is one of the most admired 

 and widely known evergreens in the 

 world and is sometimes called the 

 most beautiful of the evergreens. It 

 is somewhat limited in range, being 

 found in Colorado and Eastern Utah 

 and extending northward into Wyo- 

 ming. It seldom forms a forest, but 

 commonly grows as scattered indi- 

 viduals in groups or small groves 

 along the streams in the mountains. 

 It is most commonly found between 

 altitudes of 7,000 and 9,000 feet. Ma- 

 ture trees may reach a height of 75 

 to 100 feet with a trunk 1 to 2 feet 

 in diameter. The young trees are 

 often very symmetrical in form, es- 

 pecially when growing in the open 

 and it is during this period that they 

 are most beautiful and desirable for 

 landscape gardening. The crowns of 

 very old trees frequently become 

 quite ragged and open and the color 

 of the foliage less pleasing than in 

 youth. The needles on different in- 

 dividual trees may vary widely in 

 color from clear, bright green to sil- 

 very greenish blue. The new growth 

 is more distinctly bluisn or silvery 

 than in the older foliage, so that this 

 tree is most striking in appearance 

 just after the new foliage has reach- 

 ed its full growth in midsummer. 

 This silvery appearance is due to a 

 fine, powdery substance which is 

 produced on the surface of the 

 needles and which may be largely 

 removed by rubbing them between the 

 fingers. The branches of the blue 

 spruce commonly grow with a slight 

 upward angle, although occasional 

 specimens may be found in which the 

 branches have a drooping or weeping 

 character. The bark on young trees 

 soon becomes rough and broken into 



Fig-. 10. 



Lodgepole Pine, 

 mature tree. 



