68 BULLETIN 56, UNITED STATES NATIONAL MUSEUM. 



FRAXINUS VELUTINA Torrey. 

 lEATHERLEAF ASH. 



This is the common ash of the Mexican Boundary region. Going 

 west we first saw it in damp canyons of the Dog Mountains, and at 

 Alamo Hueco Spring, in Grant Countj^, NeAv Mexico. It was a com- 

 mon tree, west to the Patagonia Mountains, Arizona, occupying 

 damj) situations through the Elevated Central Tract, in the Upper 

 Sonoran and Transition Zones. In the Verde Valley of central 

 Arizona it grows as low as 910 meters (3,000 feet), and on San 

 Jose Mountain, State of Sonora, Mexico, it was found up to 2,290 

 meters (7,500 feet). Specimens from the Dog Mountains, New 

 Mexico, have much broader leaves than those from more western 

 localities. On the Mexican border this tree reaches the height of 

 25 meters (80 feet), with the trunk 0.G4 meter (2 feet) in diameter. 

 At the Upper Spring, in a canyon on the north side of the San Jose 

 Mountains (altitude 2,210 meters or 7,250 feet) is a grove of ash 

 trees, seven of which measure from 0.3 to 0.5 meter in diameter and 

 from 15 to 20 meters (50 to 80 feet) in height. 



CHILOPSIS LINEARIS (Cavanilles) Sweet. 

 DESERT WILLOW. 



A willow-like tree, about G meters (20 feet) in height, bearing 

 terminal racemes of purplish flowers, and seed pods 25 cm. in 

 length. (Plate IX, fig. 1.) It grows in sandy water courses in 

 dry districts from Texas to California, and belongs to the Sonoran 

 Life Zone. I obtained it at Fort Clark, Kinney County, Texas. 

 After leaving the Rio Grande it was not seen until reaching the 

 Upper Corner Monument (No. 40), in Grant County, New Mexico. 

 It was common thence in suitable localities west to Mountain Spring, 

 halfway up the east slope of the Coast Range of California. It is 

 also abundant in central Arizona. 



SAMBUCUS MEXICANA de Candolle. 

 MEXICAN ELDER. 



On the east side of the Huachuca Mountains, Arizona, 2,290 

 meters (7,500 feet) altitude, an elder tree 4.5 meters (15 feet) high, 

 with a trunk measuring nearly a meter (3 feet) in circumference, was 

 found. This specimen (No. 1559, U. S. Nat. Mus.) is marked as 

 having been determined by Dr. N. L. Britton; but I have since seen 

 the ripe fruit, which is red. It should be compared with the red- 

 berry elder {Sambucus callicarpa Greene). No equally large indi- 

 viduals were seen, but the species was found in several places in the 

 Huachuca Mountains, extending its range up into the pine belt. On 

 the San Jose Mountain, Sonora, Mexico, it was obtained from 2,200 

 to 2,225 meters (7,200 to 7,300 feet) altitude. 



