430 TiiiRTiF/rii Annual Rkport 



nowhere in the State were stock observed coming through the long 

 droughty period in better condition than here. 



Due in part to the character of the soil, some species of plants 

 were growing on this hill that were not observed elsewhere in the 

 immediate vicinity, while still other species were growing in greatei 

 abundance than on soils derived from other rock formations. How- 

 ever, the species were not unusual for southern Arizona conditions 

 and none could be suspected of being poisonous to stock. When 

 the writer visited this range no animals had died for some weeks 

 and the plant growth was rather closely grazed. Any poison plants 

 that might have been growing here had been grazed down so as 

 not to be easily recognizable. It was suggested that until such 

 time as a careful study could be made of all the conditions affecting 

 the grazing on this area, at least the lower part of the hill, where 

 the animals die, should be fenced to keep stock off from November 

 until March, inclusive. 



The following is a list of the commoner plants growing on this 

 limestone hill, as identified by the writer. The symbols, a, b, c, 

 and d after the plant names, indicate as follows : a signifies abun- 

 dant; b signifies common; c signifies occasional; d signifies in- 

 frequent. 



( 1 ) Opinitia spinosior b (12) J'igucra cordata b 



( 2 ) Ceanothus Greggii c (13) Nofholacna sinuafa b 



(3) Cercocarpus paucidcnfafus a (14) Bontcloua curtipcndula . . .a 



( 4 ) Agave Palmcri (not (15) Artistida purpurea b 



grazed, b (16) Muhlenbergia Vaseyana. .c 



( 5 ) Briekellia IVrightii c (17) Triodia sp d 



( 6 ) Opuntia Bngelmanni c (18) Bragrostis lugens b 



(7) Garrya IVrightii c (19) Bupatorium arizonicum. . .c 



(8) Dasylirion Wheeleri b (20) Andropogon saccharoides c 



( 9 ) Andropogon eirratus a (21) Mentzelia multiflora d 



(10) I'ouquiera spJcndens c (22) Quercus Toumeyi c 



(11) Rhus coriophylla b 



Dr. Lon Durham, a government veterinarian, very kindly ac- 

 companied the writer on this trip and cooperated in this study. 

 Dr. Durham failed to locate any definite symptoms of stock disease 

 that might be responsible for losses of these cattle and gave it as 

 his opinion that the trouble was due to some poison plant, possibly 

 as yet unknown as such. 



NOTES ON PLANT INTRODUCTION WORK 

 A considerable number of new plant introductions, including 

 trees, shrubs, and hardy flowers were set in the plant introduc- 



