WHITE PINES OF WESTERN NORTH A1CRICA 

 AND CENTRAL AMERICA 



R. J. Steinhoff 

 Intermountain Forest and Range Experiment Station 

 U.S. Department of Agriculture _, Forest Service 

 Moscow. Idaho. U.S.A. 



ABSTRACT 



Both species of foxtail pines (Subsection Balfourianae , Section 

 Parrya, Subgenus Strobus) grow in western North America. Pinus 

 balfouriana has a very restricted distribution while P. aristata 

 is widely distributed. Neither species is commercially important 

 but both have high esthetic value and may be useful for water- 

 shed protection or avalanche control. 



There are six species of white pines (Section Strobus, Subgenus 

 Strobus) native to western North America and Central America. 

 All of these species are rather widely distributed with one or 

 more species occurring in most of the major mountain ranges. 

 Although any of the species may occur in pure stands, they usually 

 are found mixed with several other coniferous species. 



Three of the species, P. ayacahuite 3 P. lambertiana 3 and P. 

 monticola, are commercially important and a fourth, P. 

 strobiformis is harvested, but on a much smaller scale. The 

 other two species, P. albicaulis and P. flexilis are not often 

 cut for timber but have esthetic value and are important for 

 watershed protection. 



Numerous efforts have been made throughout the world to cross 

 these species with other white pines. Several of the resulting 

 hybrid combinations show promise for a variety of uses and for 

 planting in areas where there are few or no native white pines. 



INTRODUCTION 



Subgenus Strobus of the genus Pinus has 8 representatives in western 

 North America including species in both of the Sections Strobus and Parrya. 



In Subsection Balfourianae of Section Parrya, 2 species are represented- 

 Pinus balfouriana Grev. and Balf., foxtail pine, and Pinus aristata Engelm. , 

 bristlecone pine. 



Both subsections of Section Strobus are represented in western North 

 America. Subsection Cembrae is represented by a single species, Pinus 

 albicaulis Engelm.; Subsection Strobi by species and varieties as follows: 

 Pinus flexilis James; Pinus strobiformis Engelm.; Pinus ayacahuite Ehrenb . ; 



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