Description of Wild Mustard. 163 



are usually about an inch in length. The 

 first flowers, or those borne by the earlier 

 developed plants, appear in May or early in 

 June, but the late plants will produce seeds 

 on into the month of September, or even 

 later. Fortunately, it is not a plant that 

 can withstand severe frost, hence it is not 

 found to any considerable extent in mead- 

 ows or pastures, or in fields of winter 

 wheat or rye. It is not positively known 

 how long its seeds will retain the power of 

 germination when lying in the soil, but it 

 lias been claimed that they may lie buried 

 for at least fifty years and yet immediately 

 spring into vigorous life when brought to 

 the • surface of the soil under favorable 

 conditions. 



Wild mustard will grow in all kinds of 

 soils, but not equally well. It is most at 

 home in friable limestone soils that possess 

 good drainage, but it will also grow in great 

 luxuriance on loamy prairie soils. On stiff 

 clays it does not grow so readily; but it 

 will make fair headway even in these when 

 given tlie opportunity. 



Wild mustard grows in all kinds of grain 

 crops that are sown in the spring, and usu- 

 ally it matures its seeds before the grain in 



