90 



SILVA OF NORTH AMERICA. 



CUFULLFEKiE. 



overed with hoary tomentum and rarely more than half an inch long^ is usually solitary and 



1 



ipens irregularly from the first of Septemb 



the 



d of November ; the 



'hlong^ oval 



sHghtly oh 



obtuse and rounded at the puberulous apex^ from three quarters of 



in 



ch 



an 



& 



and about half an inch broad, and is dark chestnut-brown, lustrous and often 



ipe^ but soon becomes light brown and losing its stripes as it d 



the 



tyledo 



dark 



purple^ and very 



the cup^ which 



hemispherical^ light brown and pubescent within and covered 



about a third of the nut; is deeply cup-shaped or 



regularly and closely imbricated 



broadly 



ated with thick pale tomentum^ furnished with thin light red pointed tip 



below the middle of the cup much thickened and rounded on the back. 



Quercus Arlzonlca is the most common and generally distributed White Oak of southern Arizona 

 and New Mexico, covering with Quercus Emoryi the slopes of the canons of the mountain ranges 

 south of the Colorado plateau ^ at elevations of from five to ten thousand feet above the level of the 



sea^ and many of those of northern Mexico.^ 



Growing at the 



upper edge of the mesa with Quercus 



ohlongifoUa^ it ascends nearly to the summits of the high peaks^ where it mingles with Quercus chryso- 

 lepiSy Qiiercics GcoaheWy and with Pines and Junipers. 



The wood of Quercus Arhonlca is very heavy, strong, hard, and close-grained, although liable to 

 check badly in drying ; it is dark brown or nearly black, with thick lighter colored sapwood^ and contains 



bands of 



sm 



open 



marking the layers of annual growth and connected 



rows of similar 



ducts parallel to the numerous conspicuous medullary rays. The specific gravity of the absolutely dry 



and split; it is only 



wood is 1.0092, a cubic foot weighing 62.89 pounds. Extremely difficult to cut 

 used for fuel. 



Quercus ArizonlcfA^ which has been long confounded with one of the Texas forms of Quercus 

 unclulata^ appears to have been first collected in Arizona in 1871 by the party, under command of 

 Lieutenant George M. Wheeler, sent by the government of the United States to explore the territory 

 west of the one hundredth meridian. 



To this tree, less beautiful in color, perhaps, than Quercus oblongifolicty but always attractive from 

 its pale bark and shapely head of cheerful foHage, is due much of the beauty of the forest-covering of 

 the Arizona 

 abundance. 



Mountains, where Q 



Emoryi is the only broad-leaved tree that grows 



more 



^ The sterile branches of a shrubby Oak collected by Coville and gifoliay connate cotyledons. It differs from Quercus oUongifolia 



Funston in December, 1890 {Contrib. U. S. Nat. Herb. iv. 234, in its thicker pubescent and much more coarsely reticulate leaves 



No. 4 [Bot. Death Valley ExpedJ])^ near Flagstaff, Arizona, on the and in its pubescent branchlets and larger fruit with thicker 



Colorado plateau, I can refer only to this species, although the cup-scales. In the texture, pubescence, and coloring of its leaves, 



and in the shape of some of the large broadly obovate and rounded 



An Oak found without flowers and fruit by Brandegee on Mt. individual leaves (Plate ccclxxxix. f . 6, 7) which may sometimes be 



San Pedro Martir in Lower California and referred to Quercus found on branches bearing oblong acute leaves, it resembles Quercus 

 grisea (Zoe, iv. 209) is probably of another species. 



region is far north of its range as otherwise known. 



reticulata, but its fruit is much larger and has thicker cup-scales 

 than the fruit of that species ; its bark is thicker and fissured and 

 3 Quercus Arizonica is intermediate in many of its characters generally lighter colored, and in Arizona it grows to a much larger 



441 



Mongifol 



Like these size and at lower altitudes. 



species it has purple and astringent seeds, and, like Quercus ohlon- 



EXPLANATION OF THE PLATE. 



Plate CCCLXXXIX. Quercus Arizonica. 



1. A flowering branch, natural size 



2. A staminate flower, enlarged. 



3. A pistillate flower, enlarged. 



4. A fruiting branch, natural size. 



5. A fruiting branch, natural size 



6. A sterile branch, natural size. 



7. A leaf, natural size. 



8. A leaf, natural size. 



