DISTRIBUTION AND HABITAT 255 



Loco plants in a pasture may be destroyed with a spade, but 

 the work must be done two or three times a season and repeated 

 every season. Purple loco is usually easier to eradicate than is 

 white loco, because of its habit of growing in restricted areas, 

 while white loco may cover many acres with a dense growth. 

 The cost in one experiment of eradicating loco weeds was about 

 $3 an acre for the first season, a small percentage of the customary 

 loss from poisoned stock in a single year. Experiments in 

 eradicating loco, however, have not yet been conducted on a 

 sufficiently intensive scale to demonstrate the feasibility of 

 grubbing out the species under general field conditions. Loco 

 should be dug in May or June, while it is blossoming, as the 

 plants are more readily detected and the seeds are not yet ripe. 



Special care should be taken to keep young animals away 

 from loco-infested areas, particularly where other forage is 

 scarce. As all domestic animals are more or less imitative, those 

 having the loco habit are likely to teach others the same habit. 

 Therefore locoed animals should be pastured by themselves or, 

 better still, be disposed of. If grubbing out the loco plants is 

 impracticable, either the badly infested areas should be fenced 

 against stock, or the animals should not be herded on those lands.^ 



LARKSPURS (Delphinium) 



Other common names for Delphinium are cow poison and 

 poison weed. A large number of larkspurs, widely variable in 

 size and form, grow in native pasture lands in the West. 

 When in blossom these plants are readily recognized by the 

 conspicuous spur of the flower. 



Distribution and Habitat. — There are more than twenty-five 

 native species of larkspur in the United States, but few of these 

 ire widely distributed. Some of the western species, however, 

 ire found on practically all of the stock ranges from the Rocky 

 Mountains westward, particularly in the more elevated National 

 Forest regions, where they often grow abundantly. 



The present systematic status of the larkspurs is admittedly 



1 For a detailed review of the loco-weed problem, see Marsh, C. D., "The Loco- 

 Weed Disease of the Plains," U. S. Dept. of Agr. Bui. 112, 1909. 



