WEED MIGRATION 723 



Leptochloa mucronata, Yard grass. 

 Manisurus granularis, Manisurus. 

 Cyperus rotundus, Southern nut grass. 

 Amaranthus retroflexus, Green pigweed. 

 Amaranthus hyiridus, Pigweed. 

 Amaranthus spinosus, Spiny amaranth. 

 Spergula arveiisis, Corn spurrey. 

 Portidaca oleracea, Purslane. 

 Cassia occidentalis, Senna. 

 Cassia tora, Low senna. 

 Sida rhombifolia, Rhombleaf sida. 

 Sida spinosa, Prickly sida. 

 Seneiiera pinnatifida, Peppergrass. 

 Veronica peregrina, Neckweed. 

 Veronica arvensis, Corn speedwell. 

 Lamium amplexicaule, Dead nettle. 

 Bichardia scabra, Mexican clover. 



Dr. W. A. and Mrs. Kellerman in a paper on the non-indigenous 

 Flora of Ohio, state that out of 2,060 plants of the state 430 are 

 not indigenous. Of the latter number 326 have come from Europe, 

 30 from Asia, 2 from Africa, 46 from Southern and Western United 

 States and 21 from tropical or South America. "When expressed 

 in percentages the numbers are as follows: from Europe, 75.81%; 

 from Asia, 6.99% ; from Africa, 0.47% ; from the United States, 

 10.70% ; and from tropical and South America, 4.81%. 



Comparing the Old World species with those from parts of the 

 American continent we find the numbers to be 358 and 67 re- 

 spectively. Therefore 83.25% of the introduced species have come 

 from the eastern hemisphere and 15.58% from America. 



Expressed in percentages of the total number of introduced 

 species they are as follows: waifs, 11.86%; occasionally escaped, 

 38.84% ; and thoroughly naturalized, 49.30%. 



The following list shows the families represented and the number 

 of species in each. 



1. Amaa-anthaceae, Amaranth Family 5 



2. Aizoaceae, Carpet Weed Family 1 



3. Apocynaceae, Dogbane Family 2 



4. Berieridaceae, Barberry Family 1 



5. Bignoniaceae, Bignonia Family 2 



6. ■ Boraginaceae, Borage Family 11 



