PINACEAE. 1 1 



Pinus ponderosa Dougl. Yellow or Bull Pine. Large tree, 30-80 m. tall, 

 1-4 m. in diameter, the reddish bark thick and deeply furrowed; leaves in 

 fascicles of three, 15-25 cm. long, minutely serrulate; staminate aments 

 cylindric, somewhat flexuous, 4-6 cm. long, crowded at the base of young 

 snoots; pistillate aments 1-6, greenish or purplish, borne near the apex of the 

 shoots of the season; cones brown, ovoid, 7-10 cm. long, 5-6 cm. thick, fre- 

 quently in clusters of 3-5; scales much thickened near the apex and bearing 

 a stout sharp point. Throughout our limits where the soil is gravelly. 



18. LARK. 



Tall trees with horizontal or ascending branches and small 

 narrowly linear deciduous leaves, without sheaths, in clusters on 

 short lateral scaly bud-like branchlets; aments short, lateral; 

 staminate from leafless buds; ovule-bearing buds commonly 

 leafy at the base and the aments red; mature cones ovoid or 

 cylindrical, small, erect; scales thin, spirally arranged, obtuse, 

 persistent; ovules two on the base of each scale, ripening into 

 two reflexed somewhat winged seeds. 



Larix occidentalis Nutt. Western Larch or Tamarack. A large tree, 

 30-70 m. high, 1-2 m. in diameter; bark thick, reddish, longitudinally fissured; 

 branches short, horizontal, the branchlets glabrous; buds spherical; leaves 

 narrowly linear, 2-4 cm. long, in alternate fascicles of 12-18, deciduous; cones 

 ovate-cylindric, reddish when young, brown when mature, 2-3 cm. long; 

 scales broadly oblong, truncate, ciliate-fringed when young; bracts scarious, 

 dilated at the base, the narrow terminal part exceeding the scale. A common 

 tree in the timbered foothills. 



19. PICEA. 



Evergreen conical trees, with linear short four-sided leaves, 

 spreading in all directions, falling away from the twig in drying, 

 leaving it covered with small projections; leaf -buds scaly; 

 staminate aments axillary, nearly sessile; ovule-bearing aments 

 terminal, ovoid or oblong; ovules two on the base of each scale, 

 reflexed, ripening into two more or less winged seeds; cones ovoid 

 or oblong, obtuse, pendulous; their scales numerous, spirally 

 arranged, thin, obtuse, persistent. 



Picea engelmanni Parry. Engelmann Spruce. Handsome pyramidal tree, 

 30-40 m. tall, the bark gray and scaly; branchlets pubescent; leaves dark- 

 green, quadrangular in cross section, very sharply pointed, 1.5-2 cm. long; 

 cones cylindric-ovate, 3-6 cm. long, the scales ovate, truncate, rounded or 

 retuse, crenulate. In moist places in the mountains. 



* 

 20. ABIES. 



Evergreen trees with linear flat scattered sessile leaves, spread- 

 ing so as to appear 2 -ranked but in reality spirally arranged, 

 commonly quite persistent in drying; staminate aments axillary; 

 ovule-bearing aments lateral, erect; ovules two on the base of 

 each scale, reflexed ; the scale shorter than or exceeding the thin 



