Arizona Agricultural Experiment Station 457 



Normal. In addition to this, an economic study of the plants 

 growing in the vicinity of Flagstaff was begun. One hundred 

 species of grasses, including ten not heretofore recorded for -j? 

 State, were listed and studied, and much valuable information con- 

 cerning these plants was gathered. Trips were taken in nearly 

 every direction for distances of thirty to forty miles and large plant 

 collections were made. It is estimated that at least twenty-five 

 species were added to the flora of the State in this brief study. In 

 addition to this a study of the water plants in the lakes about 

 Flagstaff, poison range plants, ornamental trees, shrubs, and vines 

 of the city, and weeds was begun. It may be interesting to note 

 that the Canada Thistle (Cirsium arvcnse) was observed for the first 

 time growing in Arizona. This matter was referred to the County 

 Agricultural Agent for disposal. 



LOSSES OF STOCK FROM AN UNKNOWN CAUSE 



(This work with rayless goldenrod was done in cooperation with 

 Dr. R. H. Williams of the Animal Husbandry Department.) 



For some years stockmen southwest of Tucson have com- 

 plained of losses on the ranges during the winter season. In a 

 specific case a rancher west of the Tucson Mountains lost 65 horses 

 and about 30 head of cattle from an unknown cause. These ani- 

 mals, with others, were grazed in three pastures, each separated 

 by several miles distance. Rayless goldenrod, or burro weed, was 

 the only plant growing in any abundance in all these pastures, and, 

 naturally, was believed to be the cause of the losses. In one 

 pasture, cattle had been kept until all the forage had been grazed 

 out, leaving only bushes of the rayless goldenrod. Stock had eaten 

 some of the fresh shoots of this plant as well as some of the woody 

 stems, both dry and green. In a second pasture, where some stock 

 were dying, there was a considerable growth of dry, rather coarse 

 grass, in addition to a small amount of annual growth and scattered 

 plants of the rayless goldenrod. Stock were eating this fresh an- 

 nual growth and the coarse grass just noted, but it was not observed 

 that they had eaten any of the rayless goldenrod. In a third pas- 

 ture, where the horses were kept, in addition to the usual growth 

 on the desert ranges, including rayless goldenrod, a scattering of 

 plants of the many-seeded saltbush (Atriplex poly car pa) was present. 

 This saltbush is regarded as good winter feed and is invariably 

 closely browsed when feed is short. No further losses of the stock 

 in these pastures resulted after the animals were given a change of 



