CRUCIFERAE (MUSTARD FAMILY) 



195 



Means of control 



Harrow autumn rosettes from the crop in the spring, when the 

 grain is but a few inches tall. Spray the young flowering stalks 

 with Iron sulfate or Copper sulfate at the appearance of the first 

 yellow blossoms. Destroy waste-land plants by deep cutting or 

 hand-pulling. 



WORMSEED OR TREACLE MUSTARD 



Erysimum cheiranthoides, L. 



Introduced. Annual or winter annual. Prop- 

 agates by seeds. 



Time of bloom: June to August. 



Seed-time: July to September. 



Range: Newfoundland to Alaska, southward 

 to North Carolina and Tennessee. 



Habitat: In fields and along streams. 



The foliage and, particularly, the seeds of 

 this weed are very bitter, and when milch 

 cattle eat it the dairy products are much 

 damaged ; also its juices are said to be so 

 irritating to mucous surfaces as to bring about 

 serious bowel disorders in stock. Its Greek 

 name means " to draw blisters." 



Stem eight inches to two feet tall, slen- 

 der, and branching. Leaves lance-shaped to 

 linear, entire or sparingly toothed, the lower 

 ones tapering to a short petiole, the upper 

 ones sessile ; the whole plant minutely rough- 

 ened with fine, forking hairs. Flowers about 

 a quarter-inch broad, bright yellow ; racemes 

 slender, the siliques four-sided, narrow, smooth, 

 a half-inch to an inch long, held erect on 

 divergent pedicels, making a noticeable elbow 

 between the pod and its stem. Seeds small, 

 reddish yellow, varying in shape from being 

 crowded in the pods but approaching a flat- 

 tened oval; too often an impurity among mum^ cheiranthoides). 

 clover seeds. (Fig. 138.) x i 



Means of control the same as for Field Peppergrass. 



