10 



TREES OF NORTH AMERICA 



while young, in old age growing very irregularly, the upper erect and much longer 

 than the usually pendidous lower branches, and stout light orange-colored, glabrous, 

 or at first puberulous, ultimately dark gray-brown or nearly black branchlets 

 clothed at the ends with long compact brush-like tufts of foliage. Bark thin, smooth, 

 milky white on the stems and branches of young trees, becoming on old trees ^'-f 

 thick, red-brown, and irregularly divided into fiat connected ridges separating on 

 the surface into small closely appressed scales. Wood light, soft, not strong, light 

 red; occasionally used for the timbers of mines and for fuel. 



Distribution. Rocky or gravelly slopes at the upper limit of tree growth from 

 the outer range of the Rocky Mountains of Colorado to those of southern Utah, cen- 

 tral and southern Nevada, southeastern California, and the San Francisco peaks of 

 northern Arizona. 



2. Leaves in l-If-leaved clusters ; cones short-stalked or nearly sessile, globose, with 

 few much-thickened scales j seeds large and edible, with rudimenlary wings. 



9. Pinus quadrifolia, Sudw. Nut Pine. Pinon. 



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

 marked on the three surfaces by numerous rows of stomata, l^'-l^' long, irregularly 



deciduous, mostly falling in their 

 third year. Flowers: staminate 

 in elongated spikes, the bracts of 

 their involucres large and conspic- 

 uous; pistillate nearly sessile. 

 Fruit subglobose, l^'-2' broad; 

 seeds narrowed and compressed 

 at the apex, rounded at the base, 

 I' long, dark red-brown and mot- 

 tled, their wings \' wide, 



A tree, 30-40^ high, with a 

 short trunk occasionally 18' in 

 diameter, and thick spreading 

 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 

 ^'-f thick, dark brown tinged with red, and divided by shallow fissures 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 California. 



Distribution. Arid mesas and low mountain slopes of Lower California south- 

 ward to the foothills of Mt. San Pedro Martir, extending northward across the bound- 

 ary 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. 



10. Pinus cembroides, Zucc. Nut Pine. Piiion. 



Leaves in 2 or 3-leaved clusters, slender, much incurved, dark green, marked by 

 rows of stomata on the 3 faces, 1-2' long, deciduous irregularly during their third and 

 fourth years. Flowers : staminate in short crowded clusters, yellow ; pistillate 



Fici 9 



