Document Type



Hamilton County flora, floristic checklist, exotic plants, rare orchids, threatened and endangered plant species, Iowa plant communities, Iowa flora


A botanical survey of the vascular flora of Hamilton County, Iowa was conducted from 2001 to 2004. During this survey 973 taxa (761 native) were encountered. A search of the literature and a survey of Iowa State University's Ada Hayden Herbarium for additional documented specimens added 28 taxa to the flora. This total of 1001 taxa places Hamilton County fourth in vascular plant richness among inventories conducted in Iowa since 1950. A checklist including common names of most taxa, habitat and abundance data for all taxa encountered during the current survey is presented. Information on earlier collections includes source and if based on a herbarium voucher, the date of the voucher collection. This study reports 12 new taxa that are not included in Eilers and Roosa's (1994) checklist of the Iowa vascular flora. Fourteen species found during this inventory are included in the 2002 Iowa Natural Resource Commission list of endangered, threatened, or special concern species. Sites containing significant plant taxa in the survey area are mapped and the notable plant taxa for each of these sites are listed.

The results of this survey provide a more thorough understanding of the flora in Hamilton County and in Iowa. These results are also important to conservation efforts such as habitat restoration and reconstruction, and in evaluating the habitat and abundance status of the vascular flora in Hamilton County and the state. This inventory exemplifies the need for similar extensive studies of the flora of other counties in Iowa. The development of a continuously maintained computer database of information on voucher specimens in the herbaria of Iowa would be an invaluable aid for conducting these studies.

Publication Date

January-December 2007

Journal Title

Journal of the Iowa Academy of Science





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© Copyright 2008 by the Iowa Academy of Science, Inc.



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