NUMBER AND KINDS OF WEEDS ON DIFFERENT SOILS 663 



Fig. 517. A cornfield from which Quaclc Grass was removed by hoeing and 

 cultivation. In adjacent checit it formed a sod. The checis was given the 

 ordinary methods of cultivation. 



(Photographed by Colburn.) 



*Convolvulus arvensis (Euro-, 



pean bindweed) 

 ^Polygonum convolvulus (Black 



bindweed) 



* Polygonum aviculare (Knot- 



grass) 

 *Bumex sp. (Dock) 

 *Tussilago farfara (Coltsfoot) 



* Mentha arvensis (Pepper- 



mint) 

 *8inapis arvensis (Common 



mustard) 

 *8onchus arvensis (Field sow 



thistle) 



*Stellaria media (Chiekweed) 



Papaver sp. (Poppy) 



* Ranunculus arvensis (Com 



crowfoot) 

 *Viola sp. (Violet) 

 Potentilla anserina ( Silver 



weed) 

 Aethusa cynapium (Fool's 



parsley) 

 ScandAx pecten-veneris (Ven- 

 us' comb) 

 Senecio vulgaris (Groundsel) 

 *Galium aparine (Cleavers) 

 Yicia sativa (Vetch) 



