158 Postelsia 
much smaller. It begins to flower and to bear 
fruit when it is only a few centimeters high. The 
ripe cones usually persist in an unopened con- 
dition and are frequently seen attached to the 
older branches and even to the trunks of the 
trees. The bark of the older trunks is thick, 
rough and furrowed both vertically and_ hori- 
zontally. 
The variety \urrayana, the lodge-pole pine 
of the interior, is a straight, slender, narrowly 
conical, thin-barked tree, often 30 meters high, 
with leaves wider than those of the type. In- 
tergrading forms connect these extremes. 
Section 2. Sivobus. “Spach. Hist. NataVex 
Phaner. 11:394.1842. emended. 
Apophysis of the cone-scale not pyramidal, 
furnished with a terminal umbo. Foliage leaves 
in fascicles of five, with a usually deciduous 
sheath of scales. 
Cones 12-25 centimeters long, cylindrical, 
ends of the scales little thickened, wing of 
seed longer than the seed. Pinus monticola 
Cones 4-8 centimeters long, their scales much 
