FLOWERING PLANTS AND FERNS OF ARIZONA 61 



1. Pinus cembroides Zucc, Akad. Wiss. Munchen Abhandl. 1: 392. 



1832. 



Chiricahua Mountains to the Baboquivari Mountains (Cochise, 

 Santa Cruz, and Pima Counties), 5,000 to 7,500 feet. Western Texas 

 to Arizona and northern Mexico. 



Mexican pinyon. The trees attain a height of 50 feet (15 m.) and a 

 trunk diameter of 14 inches (35 cm.), but are usually smaller. The 

 trunk is commonly very short, the crown compact and conic in young 

 trees, wide and rounded with mostly horizontal main branches in. older 

 trees. The bark of old trunks is thin, scaly, reddish brown. 



2. Pinus edulis Engelm. in Wisliz., Mem. North. Mex. 88. 1848. 

 Widely distributed and abundant in northern and central Arizona, 



from the Carrizo Mountains (Apache County) to the Kaibab Plateau 

 (Coconino County), southward to the White Mountains (Apache and 

 Greenlee Counties), Pinal Mountains (Gila County), and Prescott 

 (Yavapai County), 5,000 to 7,000 feet, sometimes occurring in con- 

 tinuous stands of considerable extent. Western Oklahoma and Texas 

 to Wyoming, eastern Utah, Arizona, and Baja California. 



Pinyon, nut pine. The trees are commonly straggling, with usually 

 short and often crooked trunks, attaining a height of 10.5 m. (35 feet) 

 and a trunk diameter of 75 cm. (30 inches) but usually smaller. The 

 crowns are broadly conic in young trees, rounded or flat-topped in 

 older trees. The old bark is yellowish or reddish brown, irregularly 

 furrowed, and broken superficially into small scales. Pure stands have 

 been likened to an old apple orchard. 



3. Pinus monophylla Torr. andFrem. in Frem.,Exped. Rockv Mount. 



Kpt. 319. 1845. 



Occurs sporadically in Coconino, Mohave, Yavapai, Greenlee, Gra- 

 ham, and Gila Counties, 4,000 to 6,500 feet. Utah and Arizona to 

 California and Baja California. 



Singleleaf pinyon. As it occurs in Arizona, this pine scarcely differs 

 from the ordinary pinyon {Pinus edulis) except in its solitary leaves, 

 and may be only a variant of that species. Presumably typical P. 

 monophylla, in California and Nevada, has thicker and more rigid 

 leaves and larger cones than the Arizona form. 



4. Pinus aristata Engelm., Amer. Jour. Sci., ser. 2., 34: 331. 1862. 

 Occurs in Arizona only on the San Francisco Peaks (Coconino 



County), 9,700 to 12,000 feet. Colorado and northern New Mexico 

 to northern Arizona, Nevada, and California. 



Bristlecone pine, foxtail pine. This tree reaches a height of 12 m. 

 (40 feet) and a trunk diameter of 75 cm. (30 inches) but is usually 

 smaller. The crown is pyramidal in young trees and in dense stands. 

 but older trees growing in exposed situations are characterized by long. 

 more or less erect upper limbs and long, drooping lower branches. 

 The deep-green leaves are very crowded and appressed at the ends of 

 the branchlets. The young bark is smooth and nearly white, the 

 older bark dull reddish brown and not deeply furrowed. 



5. Pinus flexilis James in Long, Exped. 2: 34. 1S23. 



San Francisco Peaks and Navajo Mountain (Coconino County). 

 probably also in the White Mountains (Apache County') and Pinaleno 



