60 BULLETIN 56, UNITED STATES NATIONAL MUSEUM. 



On the head of the Yaqui River, in Guadalupe Canyon, and along 

 Cajon Bonito Creek and the San Bernardino River the mesquite has 

 the habit of a tall, much-branched shrub, x>r frequently a small tree, 

 with a distinct trunk, bearing pods of a peculiar form and leaves 

 with crowded and very small pinnae. It is probable that at least 

 three forms of the mesquite will eventually he recognized from the 

 .Mexican border of the United States as follows: 



(1) The mesquite of eastern Texas, west to Devils River, having 

 a slender, drooping habit, with few and long leaflets; fruit not 

 seen. (2) The mesquite of the upper Rio Grande, extending thence 

 west to the Pacific Ocean; differs from the above in habit of growth 

 and in having smaller leaflets." (3) The mesquite of the San Ber- 

 nardino. Guadalupe, and Cajon Bonito creeks, headwaters of the 

 Yaqui River, having minute leaflets and a different fruit from Xo. 2. 



The mesquite loses its foliage in winter, regaining it in April and 

 May. At Maricopa, March 31, 1885. it was noted as not yet in leaf, 

 and at Deming. New Mexico. April '24, 1885, as just unfolding its 

 leaves. 



CERCIS RENIFORMIS Engelmann. 

 TEXAS REDBTJD. 



This small tree is very abundant in the vicinity of Fort Clark. 

 Texas, and thence west to Devils River, growing in the neighborhood 

 of streams. 



PARKINSONIA ACULEATA Linnaeus. 

 HORSE BEAN. 



This graceful tree is extensively cultivated in the border towns. 

 It grows from Texas to California, but was only found in a wild 

 stale in the neighborhood of La Osa and La Ventana, in Pima 

 County, Arizona, and sparingly on the Sonoyta River. Sonora, Mex- 

 ico. It is a tree of the Lower Sonoran zone. The trunk is usually 

 less than 0.84 meter (1 foot) in diameter, the tree seldom exceeding 

 9 meters (•">() feet) in height. 



PARKINSONIA MICROPHYLLA Torrey. 

 SMALLLEAF HORSE BEAN. 



A beautiful and abundant tree, on the Mexican Border between 

 the Pozo Verde Mountains and the Colorado River. It is also found 

 about Fort Lowell, and along the Gila. Salt, and Verde rivers, in 

 Arizona. The bark is smooth, waxy, and bright yellowish-green 

 throughout, including the trunk down to the ground. This tree 

 often reaches the height of aboul <*> meters (•_'<) feet), with the trunk 



■ i>r. Mearns' No. 1 is Prosopis glandulosa Torrey, his No. 2 is Prosopis velutina 

 Wooten. — Editor. 



