Add to ORKGA study was made to determine the nature of the vascular flora of Clinton, Jackson, and Jones Counties, Iowa, which had been relatively unexplored botanically (Thorne, 1954). Examination of specimens from the herbaria of the Davenport Public Museum, Iowa State College, and the State University of Iowa yielded a total of 675 species from the three counties. Specimens of the following numbers of species were found from the individual counties: Clinton County... 231 Jackson County... 142 Jones County... 560. The collections from Jones County were mainly those of R. G. Brown who reported (Brown, 1949) finding 492 species in the Jones County flora. Other collectors in the area included C. R. Ball, J. E. Cameron, L. H. Pammel, and B. Shimek