MAMMALS OF THE MEXICAN BOUNDARY. 61 



0.34 meter in diameter. We found it most abundant at Pozo de Luis 

 and in the Sonoyta Valley. Its local distribution differs from that 

 of the Palo Verde (Cercidium torreyanum) in that its habitat ex- 

 tends to the hills and rocky places instead of being restricted to the 

 edges of arroyos. 



CERCIDIUM TORREYANUM (Watson) Sargent. 

 PALO VERDE. 



This tree resembles the small-leaf horse-bean (Par7cinsonia mi- 

 crophylla), but is larger, with the hark less yellowish and waxy in 

 appearance: hark mostly smooth, but gray on the Large trunks, 

 instead of green throughout. The leaves are Larger. The well- 

 known Palo Verde is a tree of the Lower Sonoran Zone, ranging 

 from the Colorado Desert, where it blooms in April, east nearly to 

 the Pozo Verde Mountains, on the Mexican line. On the plain west 

 of the Sierra de la Salada the finest specimens of this beautiful 

 tree were seen. The largest had a trunk nearly a meter (±5 to 3 

 feet) in diameter and about 1<> meters (33 feet) in height. 



SOPHORA SECUNDIFLORA ( Cavanilles) de Candolle. 

 FRIJOLILLO; FRIGOLITO; CORAL BEAN. 



A small tree of the Rio Grande Valley, abundant in the vicinity 

 of Fort Clark. Texas, where it is known to the Americans as the 

 laurel and to the Mexicans as the " frijolillo." It bear- deep green 

 leaves of about elliptical-oblong coriaceous leaflets and showy 

 terminal racemes of violet (sometimes white) flowers, which are 

 very fragrant; but. like those of Robinia, becoming overpowering 

 and nauseating when kept in large amount in a close room. The 

 large woody pods contain 1 to 1 rounded red beans, as large as small 

 marbles, and said to be poisonous. It is abundant in Devils River 

 Valley. 



EYSENHARDTIA ORTHOCARPA (Gray) Watson. 



EYSENHARDTIA. 



A small tree in canyons on the headwaters of tin 1 Yaqui River. 

 It grows abundantly about the rock bases of Niggerhead, the Cerro 

 Gallardo, and at San Bernardino Springs. 



PAROSELA SPINOSA (Gray) Vail. 

 INDIGO THORN; MANGLE. 



This is a tree 7 to 10 meters (23 to 33 feet ) in height and '2 to 1 cm. 

 ( 7. ( .> to ir>. 7 inches) in diameter, spiny and of close habit. Its copious 

 violet -colored flowers yield a delicious fragrance. It was first met 

 with in the Sonoyta Valley, Sonora, Mexico, where, contrary to the 

 habit of other trees of the region, it grew in the sandj bottoms of 



