PINACE.E 



larly divided by remote shallow fissures and separated on the surface into numerous large 



thin light red-brown scales. Wood light, 



soft, close-grained, pale clear yellow. The 



large oily seeds are an important article of 



food in northern Mexico, and are sold in 



large quantities in Mexican towns. 



Distribution. Mountain ranges of cen- 

 tral and southern Arizona, usually only 



above elevations of 6500, often covering 



their upper slopes with open forests; in an 



isolated station on the Edwards Plateau 



on uplands and in canons at the head- 

 waters of the Frio and Nueces Rivers, 



Edwards and Kerr Counties, Texas; on 



the Sierra de Laguna, Lower California, 



and on many of the mountain ranges of Fig. 8 



northern Mexico; passing into the follow- 

 ing varieties differing only in the number of the leaves in the leaf -clusters, and in their 



thickness. 



Pinus cembroides var. Parryana Voss. Nut Pine. Piiion. 



Pinus quadrifolia Sudw. 

 Leaves in 1-5 usually 4-leaved clusters, stout, incurved, pale glaucous green, marked 



on the three surfaces by numerous rows of stomata, lj'-H' long, irregularly deciduous, 



mostly falling in their third year. 



A tree, 30-40 high, with a short trunk occasionally 18' in diameter, and thick spread- 

 ing branches forming a compact regu- 

 lar pyramidal or in old age a low 

 round-topped irregular head, and stout 

 branchlets coated at first with soft 

 pubescence, and light orange-brown. 

 Bark \ r --f thick, dark brown tinged 

 with red, and divided by shallow fis- 

 sures into broad flat connected ridges 

 covered by thick closely appressed 

 plate-like scales. Wood light, soft, 

 close-grained, pale brown or yellow. 

 The seeds form an important article 

 of food for the Indians of Lower Cali- 

 fornia. 



Distribution. Arid mesas and low 



Fig- 9 mountain slopes of Lower California 



southward to the foothills of the San 



Pedro Martir Mountains, extending northward across the boundary of California to the 



desert slopes of the Santa Rosa Mountains, Riverside County, where it is common at 



elevations of 5000 above the sea -level. 



Pinus cembroides var. edulis Voss. Nut Pine. Pinon. 



Pinus edulis Engelm. 



Leaves in 2 or rarely in 3-leaved clusters, stout, semiterete or triangular, rigid, incurved, 

 dark-green, marked by numerous rows of stomata, t'-l|' long, deciduous during the third 

 or not until the fourth or fifth year, dropping irregularly and sometimes persistent for eight 

 or nine years. 



A tree often 40-50 high with a tall trunk occasionally 2 in diameter and short erect 



