62 MISC. PUBLICATION 4 2 3, U. S. DEPT. OF AGRICULTURE 



Mountains (Graham County), 8,000 feet or higher. Alberta to 

 western Texas, Arizona, and California. 



Limber pine. In Arizona the trees reach a height of at least 15 m. 

 (50 feet) and a trunk diameter of 0.9 m. (3 feet). The trunk is 

 relatively short and the crown widely branched, with drooping limbs. 

 The bark is smooth and grayish white in young trees, but on old trunks 

 it is nearly black and split by deep furrows into wide plates. This 

 species affords a small quantity of sawed lumber in Arizona. 



6. Pinus strobiformis Engelm. in Wisliz., Mem. North. Mex. 102. 



1848. 



Pinus reflexa Engelm., Bot. Gaz. 7:4. 1882. 



White River watershed above Fort Apache (Apache or Navajo 

 County) to the Pinaleno Mountains (Graham County), Chiricahua 

 and Huachuca Mountains (Cochise County), and Santa Rita and 

 Santa Catalina Mountains (Pima County), 6,500 to 10,000 feet. 

 Southern New Mexico, southern Arizona, and northern Mexico. The 

 type of P. reflexa was collected in the Santa Rita Mountains. 



Mexican white pine. This tree attains a height of 18 to 30 m. 

 (60 to 100 feet) and a trunk diameter of 0.5 to 0.9 m. (20 to 36 inches). 

 The bark of the trunk is dark gray or dull reddish brown, somewhat 

 deeply and irregularly furrowed and narrowly ridged. The absence 

 of stomata on the backs of the leaves is said always to distinguish this 

 pine from its close relative, the limber pine. 



7. Pinus leiophylla Schlecht. and Cham., Linnaea 6: 354. 1831. 



Pinus chihvahuana Engelm. in Wisliz., Mem. North. Mex. 103. 



1848. 



White River (southern Apache or Navajo County), Pinaleno 

 Mountains (Graham County), Pinal Mountains (Gila County), 

 Chiricahua Mountains (Cochise County), and west to the Santa Rita 

 and Santa Catalina Mountains (Pima County), 5,000 to 7,500 feet, 

 mostly on dry slopes and benches, fairly common in most of its range. 

 Southwestern New Mexico, Arizona, and Mexico. 



Chihuahua pine. A relatively small tree, reaching a maximum of 18 

 m. (60 feet) in height and 0.6 m. (2 feet) in trunk diameter, with wide- 

 spreading limbs, dark brown, deeply furrowed older bark and very 

 persistent cones (pi. 9) . 



8. Pinus ponderosa Douglas ex P. Lawson, Agr. Man. 354. 1836. 



Pinus brachyptera Engelm. in Wisliz., Mem. North. Mex. 89. 



1848. 

 Pinus ponderosa var. scopulorum Engelm. in S. Wats., Bot. Calif. 



2: 126. 1880. 



Widely distributed in Arizona, from the Carrizo Mountains (Apache 

 County) to the Kaibab Plateau (Coconino County), southward to the 

 Pinaleno Mountains (Graham County), Pinal Mountains (Gila 

 County), and the Prescott region (Yavapai County), sometimes, 

 especially in Coconino County, occurring in nearly pure stands of 

 great extent, 5,500 to 8,000 feet, rarely as low as 3,600 feet or as high 

 as 9,000 feet. Widely distributed in the United States and Canada 

 from the Rocky Mountains to the States of the Pacific coast. 



