26 PINE FAMILY 



Key to the Species 



1. Twigs spreading horizontally, cones less than 



8 cm. long. 



(a) Twigs smooth, cone-scales flexible 



(1) Leaves very stiff and blue, 25-30 mm. 



long; cultivated P. pungens 



(2) Leaves slender, 10-25 mm. long; native P. canadensis 



(b) Twigs minutely hairy, leaves 5-15 mm. 



long, cone-scales stiff ; native P. mariana 



2. Twigs drooping, cones 10-20 cm. long; culti- 



vated P. Abies 



Picea pungens E n g e 1 m a n n 1879 Colorado Blue Spruce 

 Picea Parryana Sargent 1898 

 Abies Menziesii var. Parryana Andre 1876 



A tree, ,in its native regions sometimes 30 m. (100 ft.) tall, here in 

 cultivation much smaller ; branches and branchlets stiffly horizontal and 

 in layers; bark grayish brown, scaly, twigs brown, smooth; leaves 25-30 

 mm. long, four-sided, thick, stiff and sharp-pointed, pale bluish green, 

 particularly in young specimens; cones cylindrical, 6-10 cm. long, their 

 scales pale grayish brown, longer than broad, very thin and flexible, irreg- 

 ular at the outer end; pungens, pricking, referring to the sharply 

 pointed leaves. 



Cultivated: native to the Rocky Mountain regions of Colorado. 

 Wyoming, and Utah. Much planted as an ornamental tree on account 

 of its striking blue color. It is hardy, but tends with age to become 

 somewhat straggling and to take on a darker green color. Different 

 specimens vary much in the intensity of the blue color and the best are 

 sometimes propagated by grafting. 



Wood white to light brown, soft, weak, close-grained, weight 23 lb. ; 

 the wood is occasionally used locally in the mountains. 



Picea canadensis (Miller) B r i 1 1 o n, Sterns and Poggcn- 

 berg 1888 White Spruce 

 P. alba (Aiton) Link 183 1 



A large tree up to about 30 m. (100 ft.) tall ; trunk upright, straight ; 

 branches long, ascending or horizontal; bark slightly roughened, red- 

 dish or grayish brown, finally somewhat scaly, twigs light brown, smooth : 

 leaves four-sided, 10-25 mm. long, pale bluish green, unpleasant smelling 



