264 TREES OF NORTH AMERICA 



pistillate bright red, sessile or short-stalked, solitary or in elongated few-flowered 

 spikes, their involucral scales ovate, rounded, coated with soft pale tomentum, about 

 as long as the acute calyx-lobes. Fruit sessile or pedunculate; acorn oval, broad at 

 the base, obtuse and rounded or sometimes narrowed and acute at the apex, usually 

 about I' long and |' wide, frequently much smaller, dark chestnut-brown or nearly 

 black, ultimately becoming light chestnut-brown, more or less deeply inclosed in the 

 saucer-shaped, cup-shaped, or rarely turbinate cup light brown and pubescent on the 

 inner surface, coated on the outer surface with pale tomentum, and much roughened 

 below by the thickened mostly united scales rounded on the back and narrowed 

 except at the base of the cup into short pointed free tips, or rarely with the lower 

 scales only slightly thickened, with long free tips. 



A tree, 20-25 high, with a trunk 1 in diameter, or rarely 40-50 high, with a 

 trunk 18' in diameter, small branches spreading nearly at right angles and forming 

 a narrow round-topped head, and slender branchlets coated at first with short pale 

 ferrugineous tomentum, becoming light orange-brown or reddish brown and glabrous 

 or puberulous in their first winter, growing gradually darker or sometimes ashy gray 

 during their second and third years and ultimately dark brown or gray; more often 

 shrubby, forming by vigorous stolons broad low thickets 3-4 or 15-20 high, 

 with a single stem often rising high above the others. Winter-buds ovate, acute, 

 or obtuse, about % long, with light chestnut-brown pubescent scales. Bark '-' 

 thick, and deeply divided into broad irregular and often connected flat ridges 

 separating on the surface into thin dark gray scales frequently tinged with red or 

 brown. Wood heavy, hard, strong, often tough, dark red-brown, with thin lighter 

 colored sapwood; largely used for fuel. The bark is occasionally used in tanning 

 leather. 



Distribution. Eastern slopes of the Rocky Mountains of Colorado at elevations 

 of 6000-7000 above the sea, westward to the Wasatch Mountains of Utah and 

 southward over mountain ranges and high plateaus to the mouth of the Pecos 

 River, Texas, the Charleston Mountains of southwestern Nevada, and the mountains 

 of northern Sonora; common and usually shrubby on the eastern foothilk of the 

 Rocky Mountains; more abundant and the only Oak in southern and southwestern 

 Colorado, often ascending to elevations of nearly 10,000, and frequently covering 

 hillsides with interrupted thickets thousands of acres in extent; very abundant on 

 the mountains of northern New Mexico and western Texas; the common Oak of the 

 Colorado plateau, and of its largest size in southern Utah and northern Arizona at 

 elevations of 6000-7000 above the sea; on the mountains of southern New Mexico 

 and Arizona forming a narrow fringe above the groves of Evergreen Oaks and 

 below the forests of Nut Pines. 



29. Quercus minor, Sarg. Post Oak. 



Leaves oblong-obovate, usually deeply 5-lobed, with broad sinuses oblique at the 

 bottom, and short wide lobes, broad and obtusely pointed at the apex, gradually 

 narrowed and wedge-shaped or occasionally abruptly narrowed and wedge-shaped 

 or rounded at the base, when they unfold dark red above and densely pubescent, 

 at maturity thick and firm, deep dark green and roughened by scattered stellate 

 pale hairs above, covered below with gray, light yellow, or rarely silvery white 

 pubescence, usually 4'-5' long and 3'-4' across the lateral lobes, with broad light- 

 colored midribs pubescent on the upper side and tomentose or pubescent on the 

 lower, stout lateral veins arcuate and united near the margins and connected by 



