DESCRIPTIONS OF SOME COMMON WEEDS 



Tumbling Mustard (Sisymbrium altissimum, L.). A 

 leafy, branched annual, growing from two to four feet 

 tall, lower leaves runcinate, pinnatifid, irregularly toothed 

 or wavy margined ; upper leaves smaller, threadlike ; 

 flowers with four green sepals, four pale yellow petals ; in 

 older specimens only the 

 long, slender pods show 

 with small brownish seeds. 

 This weed has spread with 

 great rapidity in the United 

 States, the first specimen 

 having been observed on 

 ballast ground in Philadel- 

 phia, in 1878. It seems to 

 have been distributed large- 

 ly by railroads and is found 

 frequently along the right 

 of way. It is injurious to 

 cattle, seed containing it 

 often causing inflammation 

 and external irritation. 



Hedge Mustard (Sisym- 

 brium officinale, Scop.). A 

 coarse, unsightly annual or 

 biennial, growing from 

 three to six feet high with branching stem ; coarsely, saw- 

 toothed leaves, the points of the teeth turning down 

 toward the base of the leaf ; flowers small, pale yellow ; 

 calyx open ; pods awl-shaped, pressed closely to the 

 stem. 



Wormseed or Treacle Mustard (Erysimum cheiranthoi- 

 des, L.). A roughish, pubescent, branching annual or 

 biennial ; leaves lanceolate, entire or slightly dentate, with 

 a short petiole; flowers small, yellow; pods linear, four- 

 angled, glabrous. Native to Europe, but common along 

 streams and in moist fields in northern United States. 



Fig. 



117. Tumbling 

 rium altissimum.) 



mustard 



