B. P. I -li14. 



THE POISONOUS ACTION OF JOHNSON GRASS.' 



Johnson grass, which was introduced from Turkey into this country' 

 about 1830,^ has spread so that in manj^ pkices it is considered as a 

 weed and pest.'' Some farmers, however, have utiHzed the dried grass 

 as haj' with advantage, eitlier alone or combined with other food ma- 

 terial,^ and chemical analyses have proved its value as feed. Recently 

 reports have come to this oflSce from California of the death of cattle 

 under such circumstances as to point to Johnson grass as the causative 

 agent — the cattle dying in thirt}^ minutes after eating the grass. John- 

 son grass belongs to the same genus of the Gramineae as sorghum. 

 This group has been partially investigated chemically, and it has been 

 found that the fresh green plants of various members yield hydrocyanic 



iThis olfice has from time to time received communications from stockmen, 

 especiaUy in tlie lower part of California, Arizona, and adjacent territor\', ex- 

 pressing a suspicion that the eating of Johnson grass had caused the death of 

 stock with rather sudden and violent symptoms. There has seemed to be little 

 ground in poisonous-plant literature to support such an explanation. Last sum- 

 mer, however, convincing observations were reported from California by a stock- 

 man who had lost heavily, and a supply of the grass in question was obtained. 

 The result of the study of this material was so positive, and the possibility of 

 damage due to this unsuspected forage plant so clear, that this preliminary notice 

 is put out in the hope of getting observations and material for study from many 

 sources, in order, if possible, to determine the conditions under which the 

 poisonous properties are developed and over how wide an area they are likely 

 to appear. 



Rodney H. True, Physiologist. 



Office of Poisonous Plant Investigations, 



Washinfjton, D. C, December 11, 1905. 



-Ball, C. R. Johnson Grass. Bui. No. 11, Bureau of Plant Industry, U. S. 

 Dept. of Agriculture, 1902. 



■'Spillman, W. J. Extermination of Johnson Grass. Bui. No. 72, Part III, 

 Bureau of Plant Industry, U. S. Dept. of Agriculture, 190'). 

 ■» North Carolina Agr. Expt. Sta. Bui. 97, p. 92. 

 Vasey, G. Grasses of the South. Bui. No. 3, Division of Botany, U. S. Dept. 

 of Agriculture, 1887. 



Report of the Commissioner of Agriculture for ISSl, pp. 231, 232, 239, 241 ; 

 Report of the Secretary of Agriculture, 1890, p. 381. 



