174 



CRUCIFERAE (MUSTARD FAMILY) 



like the rest of the plant, about a quarter- 

 inch long, divided into two cells by a trans- 

 parent papery partition, which remains on 

 the thread-like pedicel after the seeds have 

 fallen like an eyeglass in a rim. Each 

 cell contains about a half-dozen flattened 

 brown seeds. 



Means of control 



Sow clean seed. Plants newly established 

 in clover field or meadow should be hand- 

 pulled or cut by themselves and burned, 

 for their seeds not only will foul the ground, 

 but also, if cured with the hay, will be made 

 certain of further distribution. Their hairy 

 surface makes these weeds susceptible to 

 injury from sprays such as Iron or Copper 

 Sulfate applied when buds are developing. 

 Early spring and late autumn cultivation 

 will destroy the seedlings and rosettes. 



PENNY CRESS 



Thldspi arvense, L. 

 FIG. 119. Gray Ber- 



teroa (Berteroa incana). Other English names: Frenchweed, Stink- 

 y i weed, Stinking Mustard, Bastard Cress, 



Wild Garlic. 



Introduced. Annual and winter annual. Propagates by seeds. 

 Time of bloom: As soon as snow melts in spring, beginning on 

 autumn plants already budded ; spring seedlings bloom later 

 and continue until fall. 

 Seed-time : Autumn plants ripen seed in early July. Spring seedlings 



mature fruit in August. Both continue seeding until winter. 

 Range : Northern and Middle Western United States ; in all Cana- 

 dian provinces, but most abundant in Manitoba and the 

 Northwest Territory. 

 Habitat: Grainfields, meadows, roadsides and waste places. 



This weed is perhaps the most hated enemy of the western farmer, 

 and is considered to have caused greater loss than any other in- 

 truder in the grain fields of Minnesota, the Dakotas, and western 



