26 LEGUMINOS^E. Pistacia. 



74. Pistacia Mexicana, HBK. 



Texas, — valley of the Rio Grande near the mouth of the Pecos River ; 

 in northern Mexico. 

 Wood not examined. 



LEGUMINOSjE. 



75. Eysenhardtia orthocarpa, Watson. 



Western Texas, valleys of the upper Guadalupe and Rio Grande, west 

 to the Santa Rita and Santa Catalina Mountains, Arizona ; in northern 

 Mexico. 



A small tree. 5 to 6 metres in height, with a trunk 0.09 to 0.15 metre 

 in diameter, or more often a low shrub ; dry. gravelly soil, reaching its 

 greatest known development, in the United States, near the summit of the 

 Santa Catalina Mountains, at 8,000 feet elevation. 



Wood heavy, hard, close-grained, very compact ; layers of annual growth 

 clearly defined by numerous rows of open ducts ; medullary rays numer- 

 ous, thin ; color light reddish-brown, the sap-wood clear yellow. 



76. Dalea spinosa, Gray. 



Colorado Desert, southern California to the valley of the lower Gila 

 River, Arizona. 



A small tree, sometimes C metres in height, with a short, stout trunk 

 0.45 to 0.50 metre in diameter, or often a low shrub ; dry, gravelly, rocky 

 soil. 



Wood light, soft, rather coarse-grained, containing many regularly dis- 

 tributed open ducts; medullary rays numerous, thin; color walnut brown, 

 the sap-wood nearly white. 



77. Robinia Pseudacacia, L. 



Locust. Black Locust. Yellow Locust. 



Alleghany Mountains, from Pennsylvania to northern Georgia ; widely 

 and generally naturalized throughout the United States east of the Rocky 

 Mountains, and possibly indigenous in northeastern and western Arkansas, 

 and on the prairies of eastern Indian Territory. 



A tree 22 to 25 metres in height, with a trunk 0.90 to 1.20 metres 

 in diameter ; west of the Mississippi River much smaller, or often a low 

 shrub 1.80 to 3 metres in height, reaching its greatest development on the 

 western slopes of the mountains of West Virginia. 



AVood heavy, exceedingly hard and strong, close-grained, compact, very 

 durable in contact with the ground ; layers of annual growth clearly marked 

 by two or three lims of large open ducts ; color brown or more rarely 

 light green, the sap-wood yellow ; largely used for treenails, posts of all 

 sorts, construction, and in turnery. 



