Nineteenth annual Meeting. 65 



LOCO WEED. 



(Astragalus mollisimus ; Nat. Ord. Leguminosse.) 



BY L. E. SAYRE, PH.G., 

 Kansas State University, Department of Pharmacy. 



The plant commonly known as Loco or Crazy Weed has for many years excited 

 much curiosity, as being one which produces upon animals who feed upon it very 

 peculiar and sometimes alarming effects. Indeed, it is said by ranchmen to cause 

 n^any of the heaviest losses among their cattle and horses. 



With a view of gathering some statistics concerning the effects of the weed upon 

 animal life, and the extent of loss therefrom, I visited, in January last, certain parts 

 of New Mexico and Colorado, and since the meeting of the Kansas Academy of 

 Science* have made a special trip for the same purpose, visiting more especially the 

 southwestern portion of Kansas, from Harper to Meade counties. The latter trip 

 was occasioned by Mr. Robert E. Steele, on the "Crooked L" ranch at Meade Center, 

 who wrote he had a locoed cow which he would place at my disposal for examination 

 if I would take the journey to his ranch. 



The plant begins to appear at about Medicine Lodge, and to extend southwest- 

 erly into the Indian Territory and northwesterly through the State of Kansas. At 

 Dodge City it was found growing abundantly in spots, although no locoed animals 

 could be found or heard of thereabouts. Ranchmen say they have not been so much 

 troubled with it in recent years, but scores had lost heavily from it in years past. 

 It was ascertained from what appears to be reliable authority, that about 500 ani- 

 mals have been lost in Meade county during the past five years from the effects of 

 this weed, though occasionally a person was met with who firmly asserted that the 

 plant in question did not cause the so-called loco disease. A butcher in Grenada, 

 Colorado, who had been interested in raising cattle and horses, and seemed to be 

 quite intelligent in his subject, most positively stated that "he did not believe one 

 word of all that was said about the Crazy weed. He had read and heard a good deal, 

 but he had yet to see an animal becoming affected by loco. He had pastured right 

 in it, and never lost one animal." A number of others gave like testimony. It would 

 be impossible in the brief space of this article to give the various and sometimes 

 conflicting statements concerning this weed. Evidently there has been a lack of ac- 

 curate and skillful observation in the matter. The great majority report that the 

 plant is truly named, as it makes the animals not only crazy, but is sure to kill them 

 eventually. Dr. P. Harding, of Dodge City, a veterinary surgeon, stated that at one 

 time he was dealing quite extensively in horses, and had lost a number from what he 

 believed to be the effect of loco. In order to satisfy himself, he performed two exper- 

 iments upon horses, with the weed; the first experiment being in the field, and the 

 next in the barn. In the field he pastured two horses, both horses having a taste for 

 loco. One of the horses found abundance of the plant in his pasture; the other 

 horse found none, because it had been carefully removed from his portion of the field. 

 The first horse died in the pasture; the second recovered from the previous feeding. 

 In the barn he also placed two horses similarly affected, and fed one with dried loco, 

 the other with clean hay. The first died and the other recovered. 



The following summary of the effect of loco is based upon personal inquiry 

 among ranchmen. The animal unaccustomed to the weed will not touch it as long 

 as good feed is to be had, but after once partaking of it — ^ driven to it in early spring 



*The present paper is a revision of the one read at the last meeting of the Kansas Academy of Sci- 

 ence, including the recent researches. 



