404 BOTANICAL GAZETTE [JUNE 
The irrigated plant is on the campus of the University of Arizona 
and has been irrigated in the same manner as the other species of 
palo verde given above. 
Fic. 5.—Parkinsonia microphylla: left, not irrigated; right, irrigated. 
PROSOPIS VELUTINA (fig. 7)—The non-irrigated specimen of 
mesquite 1s growing near the Laboratory. It is about 2™ high, 
Fic. 6.—Parkinsonia Torreyana; left, not irrigated; right, irrigated. 
gnarled, and evidently in need of a better supply of water. The 
irrigated form of mesquite is growing near an irrigating ditch in 
