WEED MIGRATION 



705 



rig. 541A Fig. 541B 



Fig. 541. A and B. Small Ragweed (.Ambrosia artemisiaefolia). An immigrant 



from the southern part of the United States. 



(Vasey, IT. S. Dept. of Agr.) 



carolinense, various species of Amarantus and Euphorbia, Pamcum 

 capillare, etc. Of late, and in consequence of increased communi- 

 cation with the Mississippi region and beyond — especially by rail- 

 roads — other plants are coming into the eastern states as weeds, 

 step by step, by somewhat rapid strides; such as Dysodia ehrysan- 

 themoides, Matricaria discoidea, and Artemisia biennis. Fifty 

 years ago Budbeckia hirta, which flourished from the AUeghanies 

 westward, was unknown farther east. Now, in tlwenty years, it has 

 become an abundant and conspicuous weed in grass fields through- 

 out the eastern states, having been accidentally disseminated with 

 red clover seed from the western stiates. 



There are also native American weeds, doubtless indigenous to 

 the region, such as Asolepias corwwti, Antennaria margaritacea and 

 A. plantaginifolia, and in enriched soils Phytolacca decandra, which 

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