Arizona Agricultural Expkriment Station 429 



any quantity of the hay were poisoned, and the ones worst affected 

 died in the corrals 6 to 15 hours afterwards. The writer examined 

 very carefully a sample of the hay weighing 25 pounds and found 

 it to be almost pure bledo or careless weed. There were a few 

 small specimens of other common plants that are not known to be 

 poisonous. These represented altogether less than one percent of 

 the total weight. The Experiment Station chemist made careful 

 analyses to determine if any of the commoner poisonous substances 

 might be found present, but in none of the tests was even a trace 

 of any poisonous substance found. Without more study it is im- 

 possible to suggest the cause of this poisoning. 



Careless weed is commonly regarded as one of our best sum- 

 mer annual forage plants and is invariably relished by stock, either 

 as dry coarse hay or as succulent green feed. Like alfalfa, occa- 

 sionally it causes bloat with stock when eaten greedily by hungry 

 animals, or following a rain or heavy dew. Considerable hay is 

 made from careless weed for winter roughage along the Gila, Santa 

 Cruz, and San Pedro rivers in southern Arizona, and, with the ex- 

 ception of the case noted above and perhaps one other at Verde, 

 Arizona, it has not been known to cause poisoning with stock. 

 Careless weed greens are considered a delicacy for the table in 

 summer and are regarded as equal to those of good spinach. In the 

 past the writer has suggested that desirable strains of bledo be 

 selected and grown as a garden vegetable. 



In November, 1918, the writer made investigations concerning 

 losses of stock on certain foothill ranges in southern Arizona in the 

 vicinity of Douglas.These losses occur late in the fall and winter 

 seasons usually following cold weather and rains and curiously 

 enough the fattest animals are the ones that are usually found dead. 

 Commonly two or more animals die at a time within a small radius, 

 mostly at places where stock collect to rest. None of the animals 

 show any evidence of struggling or violence, but usually are in 

 positions indicating rest or sleep. Along with stock from other 

 parts of the range, these animals drink from a tank of good water 

 located in a canyon some distance below. The location where 

 nearly all these animals have been found dead is a limestone hill a 

 half mile or so in extent and surrounded by foothills of native rock 

 which is non-calcareous. Similar losses of stock are known to have 

 occurred on this hill for the past eight or ten years. The range m 

 this vicinity is one of the best in southern Arizona, the forage being 

 about equally divided between perennial grasses and browse, and 



