lO PINACEAE. 



Jumperus scopulorum Sargent. Rocky Mountain Juniper. A shrub or 

 scraggly tree, 1-6 m. high, much branched, the branches often drooping; 

 foliage often glaucous; leaves small, acute, each with a linear indistinct gland 

 on the back; berries blue-black with a thick whitish bloom, maturing the 

 second year; seeds usually 2, grooved longitudinally. Spokane. 



16. THUJA. Arbor Vitae. 



Evergreen trees or shrubs; leaves small or minute, scale-like, 

 appressed, opposite, 4-ranked; flowers monoecious, both kinds 

 terminal, the staminate globose, the ovule-bearing ovoid or 

 oblong, small, their scales opposite, each bearing 2, rarely 2-5 

 erect ovules; cones ovoid or oblong, mostly spreading or re- 

 curved, their scales 6-10, coriaceous, opposite, dry, spreading 

 when mature. 



Thuja plicata Donn. Giant Cedar. Handsome pyramidal tree, 30-50 or 

 even 80 m. high, 1-5 m. in diameter, the trunk rapidly tapering from the large 

 base; branches usually somewhat drooping; bark pale grayish, thin, fibrous, 

 longitudinally fissured; wood soft, the heart-wood reddish, odorous; leaves 

 oblong-ovate, bright green, rapidly tapering to an acuminate cuspidate apex; 

 staminate aments minute, dark purple; pistillate aments usually crowded near 

 the tips of the branchlets; cones oblong, 1-1.5 cm. long, light colored, con- 

 sisting of about 6 pairs of scales, these elliptical, mucronate on the back near 

 the apex. In moist places, Kamiack Butte, and the foothills of the Coeur 

 d'Alenes but absent from the Blue Mountains. 



17. PINUS. Pine. 



Evergreen trees with two kinds of leaves; the primary ones 

 scale-like with deciduous tips; the secondary ones forming the 

 ordinary foliage, needle-like, arising from the axils of the former 

 in clusters of 2-5; ovule-bearing aments solitary or clustered, 

 each composed of numerous minute bracts, each with an ovule- 

 bearing scale in its axil; ament, upon maturing, becoming a cone; 

 the scales elongating and becoming woody; seeds two on the 

 base of each scale. 



Cone scales without prominent thickenings; leaves five in a 



fascicle. P. monticola. 



Cone scales with prominent thickenings. 



Leaves two in a fascicle. P. murrayana. 



Leaves three in a fascicle. P. ponderosa. 



Pinus monticola Dougl. Western White Pine. Tree 50-100 m. high, 1-2 m. 

 in diameter; bark gray, rather smooth, longitudinally cracked; leaves pale 

 green, in fascicles of five, 4-7 cm. long; cones narrowly cylindrical, 15-30 cm. 

 long, about 4 cm. thick. In the mountains at low altitudes. 



Pinus murrayana Balf. Lodgepole Pine. Small tree, 10-20 m. tall, the 

 dark bark usually deeply checked; leaves 4-8 cm. long, dark green; cones 

 small, ovoid, 4-5 cm. long; scales thickened at the apex and armed with a 

 stout point. In the mountains at low altitudes often forming dense pure 

 growths of nearly equal-sized trees. 



