WEEDS OF MONTANA. 



31 



21. BRAS5ICA SINAPISTRUM, Boiss. Wild Mustard; Charlock. 



Resembling the B. Campestris above, but is more or less hairy 

 throughout. One of the worst weeds of the state, fairly taking 

 many of the grain fields in low land. 

 Should be combatted like the wild oat 

 and the sunflower. Hand pulling 

 may be emplo3'ed when it occurs onh- 

 in small patches. Every effort should 

 be made to prevent its introduction 

 into a community and combined ac- 

 tion should be taken to clear infested 

 fields, as the seeds appear to be 

 spread largely by irrigation. [Fig. 4.] 



22. BROMUS RACEMOSUS, L. 

 An annual Brome-grass not in- 

 frequent as a weed in fields and w^aste 

 places; commonly confused with the 

 next, which it closely resembles. 



23. BROMUS SECALINUS, L. 

 Cheat; Chess. 

 Differs from the last in its more 

 diffuse panicle and its larger and flat- 

 ter spikelets. Not rare in agricultural 

 districts of the state and often a very 

 bad weed in grain fields in the Flat- 

 head valley. 



24. *BROMUS TECTORUM, L. Downy Brome-grass. 

 A small annual grass with long-awned pendulous spikes well es- 

 tablished at Columbia Falls and Missoula, in streets and waste 

 places and promises to spread into other parts of the state. In- 

 troduced from Europe. 



25. CAMELINA 5ATIVA, Crantz. False Flax. 

 An annual with light yellow flowers and a pear-shaped pod of 

 the Mustard family and resembling somewhat the cultivated flax. 

 A frequent and occasionally troublesome weed in grain fields 



Usually imported in the grain seed sown. 



Fig. 4. Brassica Sinapistrum, 

 Boiss, Vi natural size. 



throughout the state 



