102 OUR NATIONAL FORESTS 



stacle to efficient range management was overcome 

 when a system of plant collection and identification 

 was started by the Forest Service. Some 23,000 

 specimens of about 3,000 different species have 

 been collected on the National Forests, identified 

 by specialists and the collector informed as to the 

 value of each species. The identification of range 

 plants is the first step toward securing an intimate 

 knowledge of the life history of the plant. Such 

 information as the soil and moisture requirements, 

 date of flowering and seeding, requirements for re- 

 production, and its relation to other range plants 

 is of the utmost importance if the maximum forage 

 crop is to be produced on the range each year. 

 This constitutes the latest stage in the development 

 of grazing studies. 



Investigations Dealing with Poisonous Plants 

 and Predatory Animals. In cooperation with the 

 Bureau of Plant Industry the study of poisonous 

 plants and the means for reducing the losses from 

 them has been undertaken. The death camas, the 

 lupines, the larkspurs, some of the wild cherries, 

 locoweed, and practically all species of zygadenus 

 are plants that have been found to cause death 

 among stock. While the handhng of stock to 



