36 WEEDS OF FARMLAND 



range of the weed. Rootlets are given off from the creeping 

 stems, and if the latter are broKen up every small piece that 

 bears a bud or young shoot is capable of striking root for itself 



> 



FIG. 20. SORREL (Rumex acetosa). 



A. Aerial Shoot. C. Scars of old Aerial Shoots. 



B. Thickened Underground Stem. D. Roots. 



and forming an independent plant. In bindweed (Convolvulus 

 arvensis) (Fig. 13), thistle (Cirsium arvense'} (Fig. 14), horse- 

 tail (Equisetum arvense) (Fig. 1 5), couchgrass (Agropyron repens) 

 (Fig. 1 6), and sheep's sorrel (Rumex acetosella] (Fig. 38), the 

 underground stem is fairly thin, but in corn sowthistle 



