WEED MIGRATION 761 



Low Hop Clover {Trifolium procumbens L.). 



Ames, 1882 (Hitchcock) ; Iowa City, 1884 (Hitchcock). It is now 

 frequent in Ames ; also in northeastern Iowa, in Waukon, Decorah 

 and Dubuque, also in Clayton county. 



Dakota Vetch {Hosackia purshiana Benth.). 



Indigenous to the loess of Iowa along Missouri river. Sioux City, 

 naturalized. Boone, 1895 (G. W. Carver). 



Black medick {Medicago lupulina). 



Eeported by Dr. John Torrey in 1826 as occurring in fields, also 

 by Dr. Gray in 1848 and Dr. Darlington in 1853. In the fifth 

 edition of Gray's manual it was said to be "adventitious from Eu- 

 rope in waste places." Britton, in 1901, states, "In fields and 

 waste places, common only throughout our area. ' ' It was found in 

 Kossuth county, Iowa, in 1898; at Ames, 1871 (C. E. Bessey) ; 

 1898 (A. F. Sample and E. R. Hodson). Mr. F. W. Paige records 

 having seen it in Fort Dodge about 1900. 



MALVACEAE, MALLOW FAMILY. 



Shoo-fly {Hibiscus trionum). 



Reported in the first edition of Gray's manual in 1848. It is 

 also mentioned by Darlington in 1853 as occurring in gardens and 

 lots. The fifth edition of Gray's manual states, "advanced from 

 Europe." The seventh edition gives "a wide distribution, culti- 



PiG. 565. Shoo-fly (Hibiscus trionum). This weed was widely distributed as 



an ornamental plant. 

 (Drawing by Charlotte M. King.) 



