WEEDS AND WEED CONTROL 



247 



Purslane (Portulaca oleracea). This is a bad weed in gardens (Fig. 

 103). The experiments of W. J. Beal show that the seeds retain their 



PIG. 102. Sheep sorrel (Rumex acelosella). A common weed in pastures and mea- 

 dows, from Europe. (Division of Bot., U. S. Dept. of Agriculture.) (Reproduced in 

 Pommel, L. H.: Some Weeds of Iowa, Bull. 70 Experiment Station, Iowa State College, 

 1903, P- 348.) 



vitality in the soil for thirty years. It spreads over the ground with 

 thick, alternate, obovate leaves. The small, black seeds are produced in 



