PLANTS' POISONOUS TO STOCK. 



237 



Specimens of the three following species of Astragalus have been for- 

 warded to the Division of Botany with the information that they were 

 causing great financial loss in the districts noted. It is quite probable 

 that other species are dangerous also. 



POISONING BY WHITE LOCO WEED (aEAGALLUS SPICATUS). 



This is an erect tufted perennial, 4 to 18 inches high, with pinnately 



Fig. 91. — Steinless loco weed 

 {Aragallus lamhertii). a, 

 Flowering plant; h, seed 

 pods ; c, cross-section of 

 seed pod — all one - third 

 natural size. 



\ 



Mm\W 



\j ^ 





Fig. 92. — Woolly loco weed (Asfragalws 

 v2ollissimus). a, Whole plant ; b, sec- 

 tion of pod — both one-third natural 

 size. 



divided leaves and spikes of white or cream-coloured flowers, shaped like 

 those of the pea. The pod is one-celled, and when shaken produces a 

 rattling sound, which gives the plant the name of " rattle weed " in some 

 localities. The white loco weed is exceedingly common throughout Mon- 

 tana. It occurs most abundantly on the northern slopes of foothills up 

 to an altitude of about 8,000 feet. Its preferred habitat is for the most 



