233. JUG-LANS RUPESTKIS MEXICAN WALNUT. 31 



The trunk is generally short, divided at from 6-8 ft. from the ground 

 into large branches, most of which grow out horizontally, or droop 

 downwards and all conform into a low symmetrical wide top. 



HABITAT. Central Texas, the upper Colorado, Llano and Guada- 

 loupe Rivers, westward through southern New Mexico and Arizona, 

 where it attains its largest dimensions, and southward into northern 

 Mexico. It is found along the banks of streams and in mountain 

 canons up to an altitude of about 6000 ft. It is often shrubby in the 

 extreme eastern portion of its range. 



PHYSICAL PROPERTIES. The wood of the Arizona Walnut is heavy, 

 of moderate hardness and strength, with large open ducts irregularly 

 distributed, of a rich dark brown color with yellowish white sap-wood, 

 when freshly cut, but quickly assuming a light brown color on exposure 

 to the atmosphere. Specific Gravity, 0.6554; Percentage of Ash, 

 1.01; Relative Approximate Fuel Value, 0.6488; Coefficient of 

 Elasticity, 72632; Mod alas of Rupture, 600; Resistance to Long i- 

 tudinal Pressure, 437; Resistance to Indentation, 182; Weight of a 

 Cubic Foot in Pounds, 40.84. 



USES. The nuts of this tree are prized by the Mexicans and Indians 

 as an article of food though too small and with too hard shells to have 

 attained any commercial importance. Little use is made of its wood 

 owing to the sparse ness of the population of the regions in which the 

 tree is found and its inconvenient dimensions. 



ORDER CUPULIFBRJE: OAK FAMILY. 



Leaves alternate, simple, straight veined; the stipules, forming the bud-scales, 

 deciduous. Flowers monoecious, apetalous. Sterile flowers in clustered or racemed 

 catkins (or in simple clusters in the Beech); calyx regular or scale-like; stamens 

 5-20. Fertile flowers solitary, clustered or spiked, and furnished with an invo- 

 lucre which forms a cup or covering to the nut; calyx-tube adherent to the ovary, 

 its teeth minute and crowning the summit; ovary 2-7-celled with 1-2 pendulous 

 ovules in each cell, but all of the cells and ovules, except one, disappearing before 

 maturity; stigmas sessile. Fruit a 1-celled, 1-seeded nut, solitary or several 

 together and partly or wholly covered by the scaly (in some cases echinate) irivo- 

 lucral cup or covering; seed alburnenless, with an anatrapous, often edible, 

 embryo; cotyledons thick and fleshy. 



Genus is represented by both trees and shrubs. 



GENUS QUERCUS, L. 



Flowers greenish or yellowish, Sterile flowers in loose, slender, naked catkins, 

 which spring singly or several together from axillary buds ; calyx 2-8-parted or 

 cleft ; stamens 3-12 ; anthers 2-celled. Fertile flowers with ovary nearly 3-celled 

 and 6-ovuled, two of the cells and 5 of the ovules being abortive ; stigma 3-lobed; 

 involucre developing into a hard, scaly cup around the base of the nut or acorn, 

 which is 1-celled, 1-seeded. 



(Quercus is the ancient Latin name for the Oak supposed to be from the Celtic 

 quer, fine, and cuez, tree.) 



