EVERGREENS OF COLORADO 19 



are more composed of numerous thick, hard scales each tipped with a 

 slender prickle. A strong heat, such as that produced by a light forest 

 fire, will cause these "tight cones" to open and allow the seeds to fall 

 out. As the seeds may retain their vitality in these cones sometimes 

 for 20 years, a quick forest fire often brings about a generous reseeding 

 of the burned area by causing these closed cones to open. 



While the wood of the lodge pole pine is of inferior quality, it is 

 quite extensively used for railway ties, mine timbers, telephone poles, 

 fence posts and to some extent for sawn lumber. Its durability can be 

 greatly increased by treating with some timber preservative and its use- 

 fulness extended for all purposes where it is used in contact with the soil. 



5. THE PINYON PINE. 

 /'in us editlis Engelm. 



The pinyon pine occurs chiefly at moderate elevations, forming scat- 

 tered groves or open forests, frequently mixed with Western Red Cedar 

 among the eastern and western foothills of the Rocky Mountains of Colo- 

 rado, in southwestern Wyoming and western Texas and Arizona. It may 

 be looked for between elevations of 4,000 and 9,000 feet, but is most com- 

 mon at altitudes of about 5,000 to 7,000 feet. It is a tree of small or 

 medium size with compact rounded crown, which extends nearly to the 

 base of the trunk. It rarely exceeds 20 to 30 feet in height, with a trunk 

 diameter of 1 to 2 feet. The needles are in bundles of 2, occasionally 

 3, and are about 1 inch in length. The trunk usually tapers rapidly up- 

 ward and is frequently branched. The bark is from a half to three- 

 quarters of an inch in thickness on old trees and is irregularly divided 

 into ridges covered with small, blackish brown scales. 



The wood is light, soft, brittle and light brown in color. The 

 cones are nearly spherical in form and about equal in length to the 

 needles. The few scales of which they are composed are without 

 prickles. The seeds are larger than those of any other of our pines. 

 They are usually about half an inch in length or the size of ordinary 

 field teans and are wingless when separated from the scales of the cone. 

 The wood of the pinyon pine is seldom used for lumber on account of 

 the short, knotty trunks. It has been extensively used, however, for 

 fuel and the manufacture of charcoal and to some extent for fence posts. 

 The seeds have been extensively collected by the Indians who made use 

 of them for food, and they are still a common article to be found at 

 confectioners' stands. 



2. GENUS Picea THE SPRUCES. 



The spruces are mostly tall growing trees with conical or pyramidal 

 crowns and tapering trunks when grown in the open. They are most 

 readily distinguished from the pines by the needles, which are single and 

 possessed of a very short, stalk-like portion at the base. In the case of 

 needles which are one year old, this stalk-like base is brown in color 

 and is apparently jointed to the green upper part of the needle. These 



