32 HOUGH'S AMERICAN WOODS. 



234. QUERCUS EMORYI, TORR. 



EMORY OAK. ARIZONA BLACK OAK. 



Ger., Eiche von Emory; Fr., Chene (T Emory; Sp., Roble de Emory. 



SPECIFIC CHARACTERS : Leaves oblong-lanceolate, from 1-'2| in. in length, 

 acute, cordate or rounded at base, entire or repand-serrate with 1-5 pairs of 

 mucronate teeth, pubescent at first but at maturity glabrous or stellate-puberul- 

 ous, coriaceous, lustrous dark green above, paler and with whitish pubescence at 

 the base beneath, persistent during the winter and until after the appearance of 

 new leaves. Flowers appear in April, the staminate in hoary -tomentose aments 

 2-3 in. in length ; calyx light yellow, 5-7-lobed, pubescent outside ; stamens with 

 short filaments and large yellow oblong anthers ; pistillate flowers sessile or nearly 

 so, hoary-tomentose. Fruit acorns maturing the first season, sessile or nearly so, 

 with oblong-ovoid nut, -f in. long, whitish tomentose within and ^ invested by 

 the cup, which is nearly hemispherical and with close imbricated thin scarious 

 light brown pubescent scales ; cotyledons yellow and of sweetish flavor. 



The specific name commemorates the name of Col. W. H. Emory who dis- 

 covered this species in southern New Mexico. 



A beautiful and distinct oak attaining the height of 60 or 70 ft. 

 (20 m.) with a trunk diameter of 3 or 4 ft. (1.20 m.) having a very 

 dark brown bark deeply fissured into small firm square and oblong 

 plates which exfoliate in fragments and thick scales. Its trunk usually 

 divides within a few feet of the ground into sturdy arching branches, 

 the lowermost of which rise obliquely and a rather flattened obconic 

 head is formed. Along the large trunks many small branches are 

 giv^en out which form flattened sprays of shining dark green foliage. 

 These features give this oak an individuality and beauty which at once 

 distinguish it from all other trees in the region in which it grows. 



HABITAT. The Emory Oak is found on the mountains of western 

 Texas, southern New Mexico and Arizona, south of the Colorado 

 plateau, and southward into Mexico. It grows in considerable abund- 

 ance in the open forests which clothe the mountain slopes, but attains 

 its best development and beauty in the sheltered canons of the 

 mountains of southern Arizona. 



PHYSICAL PROPERTIES. Wood heavy, hard, strong, coarse-grained, 

 with annual rings distinctly marked by large open ducts, and of a 

 mottled dark and light brown color with lighter sap-wood. Specific 

 Gravity, 0.9263; Percentage of Ash, 2.36; Relative Approximate 

 Fuel Value, 0.9044; Coefficient of Elasticity, 63828; Modulus of 

 Rupture, 703; Resistance to Longitudinal Pressure, 422; Resistance 

 to Indentation, 415; Weight of a CMo Foot in Pounds, 57.73. 



USES. The edible acorns of the oak are highly valued by the 

 Mexicans and Indians as an article of food and are of commercial 

 importance in the towns of southern Arizona and northern Mexico. 



