PINACEAE 



Limber Pine 

 Pinus flexilis James 



HABIT. A tree 25-50 feet high (max. 85 by 6/3 feet); 

 crown broad, open, with large, plumelike, often drooping 

 branches. 



LEAVES. In fascicles of 5; 13^-3 inches long; stout; rigid; 

 dark green; persistent 5-6 years; sheath deciduous; margins 

 with minute teeth; marked on all sides by rows of stomata. 



FLOWERS. Male red; female clustered, red-purple. 



FRUIT. Cones short-stalked; 3-10 inches long; subcylin- 

 drical; open at maturity; scales greatly thickened and often 

 slightly reflexed, with terminal unarmed umbo. Seed: Yi-Vz 

 inch long; wingless; thick, light brown shell. The variety reflexa 

 Engelm. {P. strobiformis Engelm.) of the Mexican border has 

 strongly reflexed cone scales. 



TWIGS. Stout and tough; smooth and silver-white or gray. 

 Winter buds: Vi-Vi inch long; broad ovoid and pointed. 



BARK. Characteristically thin, smooth, white-gray. 



WOOD. Unimportant; moderately light and soft; close- 

 grained; used locally for mine props, railroad ties, etc. 



SILVICAL CHARACTERS. Very intolerant; growth slow; 

 maturity reached in 200-300 years; tree very windfirm with 

 taproot; fire, blister" rust, and bark beetles cause damage. 



HABITAT. Upper Sonoran to Hudsonian zones; altitu- 

 dinal range from 4,000-11,500 feet; adapted to wide variety of 

 sites, but typical of summits and rocky foothills. 



* * * 



Whites ARK Pine 



Pinus albicaulis Engelm. 



A subalpine tree almost indistinguishable from limber pine 

 except for its very characteristic cones. 



FRUIT. Cones short-stalked; lV^-3 inches long; subglobose; 

 closed at maturity and opening by disintegrating at the axis; 

 purple-brown; scales thick with stout, pointed umbos. 



