42 



THE MONTANA EXPERIMENT STATION. 



grain fields and cultivated ground. Occasional along the rail- 

 ways in the western part of the state, but not troublesome there 

 except in the Bitter Root valley. It is confined to one or two 

 small areas in the Flathead valley and shows small disposition 

 to spread in the absence of irrigation, but if the farmers are wise 

 they will stamp out this pest at once, lest it become as trouble- 

 some there as it has in other parts of the state. Seeds seem to 

 be distributed largely by irrigation and in the mud adhering to 

 to feet and to the wheels of vehicles. Its seeds seem to lie in the 

 ground many years before losing their vitality and it can best be 

 combatted by sowing the infected fields in some annual grain 

 suitable for forage and pasturing with sheep for several years. 



62. HELIANTHUS NUTTALLII, T. &. G. 



Fier. 10. 



Horde 

 Naturi 



umjubatum, L. 

 al size. 



A native perennial sunflower, more 

 slender and with narrower leaves than 

 the last; roots tuberous and with 

 frequent underground stems. Usually in 

 small patches, and can best be destroyed 

 by pulling or digging after irrigation. 

 Often troublesome in grain fields and 

 low ground in the western part of the 

 state. 

 63. HELIANTHUS PETIOLARIS, 

 Nutt. 



An annual very like and commonly 

 confused with H. annuus above and fre- 

 quent in dry, sandy situations in the 

 Milk River and Yellowstone valleys. It 

 has smaller heads than the common sun- 

 flower (H. annuus) and narrower, en- 

 tire leaves. 



64. HORDEUM JUBATUM, L. Foxtail; 



Squirrel-tail Grass; Slough-grass. 



An annual or biennial grass with a 

 large, bushy spike of fruit, whose long 



