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 acetosella). 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 Stale 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 



