The Evergreen Trees oe Colorado. 25 
The lodge pole pine is capable of making a rapid growth under favor¬ 
able conditions. It prefers a moist sbill and may be used in the wind-break 
where such conditions prevail. When well established, however, it is hardy 
and enduring. 
PINON^ NUT PINE. 
(Pinus Edulis (^ngelm.) Caryopitys Edulis Colo. Bulletin lOO.) 
(Plate V. b. d.) 
This is the pine from which the pinon nuts sold by fruit venders in 
cities are obtained. The tree is of small or medium size, with compact, 
pyramidal or rounded head. It occurs scattered or in open forests among 
the eastern and western foothills of Colorado, in southwestern Wyoming and 
western Texas and Arizona. It is not a tree of the high altitudes. The short, 
stiff leaves are in bundles of two and about one inch in length. The short, 
broad cones equal the leaves in length and are composed of few scales. The 
seeds are the largest of those of any other pine in this regtion. They are about 
the size of field beans and are wingless when separated from the scales of 
the cones. 
This tree is useful mainly for its edible seeds, although the wood is 
sometimes made into lumber. It is quite extensively used for fuel and the 
manufacture of charcoal. 
The pinon pine is adapted to growing in dry situations and for this rea¬ 
son may be planted where moisture is lacking. Its low, stocky growth adapts 
it for pianting where a low mass of evergreen foliage is desired. The seeds 
germinate readily and this tree may be quite readily grown in this way. The 
seedlings may be transplanted at two years of age to encourage a comp 3 ,ct 
root development. 
GENUS Picea — THE spruces. 
The spruces are tall growing trees with conical or pyramidal 
form and tapering trunks. The needles are single, which dis¬ 
tinguishes these trees from the pines, four angled and 
sharp tipped. At the base a short stalk-like portion is jointed to the 
green part of the needle and remains on the branchlet after the 
upper part of the needle has fallen. This makes the branchlets 
from which the leaves have fallen very rough and readily serves 
to distinguish the spruces from the firs. 
The bark of the older limbs and trunks is usually dark gray¬ 
ish or reddish brown and consists of thin scales. The cones are 
hanging 01 pendulous when ripening and occur in the uppermost 
parts of the tree. They consist of thin scales each bearing two 
winged seed^^. The seeds mature in the autumn of the first year. 
They are mostly small, pointed at the base and furnished with 
long, thin wings. 
The spruces furnish some of our most ornamental evergreen 
trees, besides which they are useful in forming hedges, wind¬ 
breaks and shelter belts. 
KEY TO THE COLORADO SPECIES OE Picca. 
A. Needles very stiff and sharp pointed, surface of twigs among the needles 
entirely glabrous or free from hairyness; cones 5-7.5 c. m. (2-3 in.) long. 
1. Picea Parry ana. 
