CONE-BEARERS. 23 



No. s-Arizona White Pine 



P. Ayacahuite, Ehrenb. Var. strobiformis, Sargent. 



Large trees of the highest mountains in Arizona 



and Northern Mexico, with cone-scales long, thick 



and spoon-shaped, strongly reflexed at maturity 



(hence once named P. reflexa by Dr. Engelmann). 



Croup 2. Alpine White Pines. 



Alpince. 



Smaller, often depressed and very aged trees of the 

 Southern Kocky Mountains and Great Basin region, 

 or alpine on peaks of more northern and western 

 regions. 



Two species: 



NO. 4 Rocky Mountain White Pine 



P.flexilis, James. 



Standard or sometimes depressed trees of the Rocky 

 Mountains and a few on the peaks of certain 

 mountains of Nevada, Northern Arizona, and the 

 Southern Sierra. The principal timber tree of Utah 

 and Nevada. Branches often very slender, in south- 

 ern forms (Northern Arizona) quite robust. 

 ARIZONA FLEXILIS PINE. Var. macrocarpa, Engelm. 



A round-headed tree on the San Francisco 

 Mountains, Northern Arizona, with more robust 

 branchlets and larger cones, 6 to 8 inches long. 



