Il8 UNIVERSITY OF COLORADO STUDIES 



with junipers it is common on the hills and table lands of western Colorado. It 

 does not occur at very high altitudes. 



Pinus scopulorum (Engelm.) Lemmon. Rock Pine, Westeiin Yellow Pine 



Rydberg, Flora Colo. 7; Coulter, Manual 432 (as P. ponderosa, var. scopu- 

 lorum); Sargent, Manual Trees of N. A. 15 (as P. ponderosa, var. scopulorum); 

 Nelson, Key to Rocky Mountain Flora 6. 



Leaves in bundles of two or three, variable as to number even on the same tree; 

 stout, dark yellowish-green, often in bottle-brush arrangement at the ends of naked 

 branches; 8 to 15 cm. lofig. Staminate flowers yellow; carpellate dark red. Cone 

 6 to 9 cm. long, the cone scales each with a stout sharp prickle. The young cones 

 are erect the first summer; when fully grown they are horizontal or slightly declining. 



A handsome spreading tree, the largest of our pines, with thick deeply-furrowed, 

 reddish bark becoming very thick on old trees. Wood hard and strong but differing 

 greatly in quality; where abundant it is sawed into lumber or used for railway ties 

 and mine timbers. The specific gravity is 0.4619. 



Hills and ridges of western Nebraska to Rocky Mountain region and from 

 Montana to Arizona and New Mexico, forming on the Colorado plateau the most 

 extensive pine forests of the continent. 



On account of its resistance to drought this tree should be a valuable one for 

 planting in semi-arid districts. The large seeds germinate freely and the trees are 

 easily grown when given reasonable care. 



Pinus murrayana " Oreg. Com. " Lodgepole Pine 



Rydberg, Flora Colo. 8; Coulter, Manual 433 (as P. contorta, var. murray- 

 ana); Sargent, Manual Trees of N.A. 27 (as P. contorta, var. murrayana); Nelson, 

 Key to Rocky Mountain Flora 5. 



Leaves in bundles of 2, yellow-green, 3 to 6 cm. long. Staminate flowers 

 orange -yellow, carpellate reddish. Cone about the same length as the leaves, very 

 persistent, often remaining attached three or four years after ripening; cone scales 

 with short, sharp prickles. Seeds winged. 



A tall, straight tree, generally growing in dense groves on north slopes in the 

 foothills. The trees have been considered of little value for lumber but they are 

 certainly most useful in holding the soil and in protecting snow from too rapid melt- 

 ing. Seeds of this pine, unlike those of most species, retain their vitality for a num- 

 ber of years. Burned districts become reseeded by the opening of the cones which 

 takes place on account of the heat produced by the fire. Wood rather light and 

 soft, not durable; specific gravity 0.4096. Used to some extent for ties, mine 

 timber and fuel when better wood is not available. Recently developed methods of 

 seasoning and preservative treatment promise to make the lodgepole pine valuable 

 for railway ties and mine timbers. 



