Checklist 1.0 Sources
The checklist 1.0 (linked above) is composed of synonymized vascular plant records from the following sources:
- My personal collections
- My unpublished data on the vascular flora of Rock Island County, IL (project in progress)
- My site inventory data from natural areas throughout the region
- My iNaturalist observation records
- A limited number of iNaturalist observations from other citizen scientists and professional botanists (I intended to incorporate more in the future)
- Herbaria specimen records accessed online from the Consortium of Midwest Herbaria (midwestherbaria.org)
- County-level distribution records for endangered, threatened, and watchlist vascular plants in Iowa (available online from the IA DNR)
- County-level distribution records for endangered and threatened vascular plants in Illinois (also available online from the IL DNR)
Plus, the following publications:
- Guldner, Ludwig F. 1960. Vascular Plants of Scott and Muscatine Counties. Davenport Academy of Sciences.
- Dobbs, Raymond. 1963. Flora of Henry County, IL. The Natural Land Institute.
- Fay, Marcus J. 1951. The Flora of Cedar County, Iowa. Proceedings of the Iowa Academy of Sciences.
- Fay, M. & Thorne, R. 1953. Additions to the Flora of Cedar County, Iowa. Proceedings of the Iowa Academy of Sciences.
- Morrissey, Thomas. 1956. The Flora of the Pine Hill Prairie Relic. Proceedings of the Iowa Academy of Sciences.
- Ebinger et al. 2006. Vegetation and Flora of the Sand Deposits of the Mississippi River Valley in Northwestern Illinois. Illinois Natural History Bulletin.
- Widrlechner, Mark. 1998. The Genus Rubus in Iowa. Southern Appalachian Botanical Society.
Shortcomings of the current checklist and ongoing challenges
While I have confidence that this list is a good estimation of our historic and contemporary spontaneous vascular flora, it is not without its shortcomings. Perhaps one of the more inherent issues, at least at this stage, is the reliance on published records and unverified specimens. This list takes previous botanists at their word for the vascular plant taxa that they reported. In an ideal world, all specimens would be inspected in order to confirm or update determinations. This is perhaps the most arduous aspect of a project like this, and it will be undertaken gradually over the long term. Thanks to digitization, however, this process is becoming easier. To guard against diluting the checklist, I have excluded numerous doubtful or problematic records for species that are unlikely to occur or have occurred here.
Taxonomic challenges crop up with certain genera. Some of the more challenging include Crataegus, Dichanthelium, and Rubus. Crataegus, like other members of the Rosaceae, is known for its capacity for great morphological variability and hybridization which conspire to confound confident species-level determinations. According to some authorities in the past, the genus contained many hundreds of species, many of which are likely apomictic microspecies. Other authorities suggest there are, instead, only around 200 species in the genus. At present, I am leaning on Mohlenbrock’s Vascular Flora of Illinois (2014) and Wilhelm and Rericha’s Flora of the Chicago Region (2017) when it comes to this challenging group.
The genus Rubus shares a similar taxonomic history to Crataegus, with different authorities citing between 20 to 500 species in Eastern North America alone. This dichotomy of “lumpers” and “splitters” has made understanding our Rubi especially challenging. However, I am following the treatment of the genus by Dr. Mark Widrlechner (Iowa State University, retired) who has amassed decades of experience and wisdom regarding our Midwestern brambles. He has annotated Rubus collections at BDI and ILL/ILLS which contain most of our historic Rubus collections. Resultingly, the majority of Rubus taxa reported in this list are based on his determinations.
Finally, while the taxonomy of the genus Dichanthelium is not as thoroughly problematic relative to Crataegus and Rubus, there appears to be a variety of differing perspectives on its taxonomy. I find that different dichotomous keys often produce different determinations, especially with specimens in the Dichanthelium acuminatum complex. Further clarity and study is needed.
Underbotanized counties and areas in need of more work
Of the eight counties covered in this project, not all have received proportional floristic attention. We are lucky to have relatively thorough inventories published for four counties (plus my unpublished work on Rock Island County), but three remain without such efforts. These are Clinton County, IA, Mercer County, IL, and Whiteside County, IL. In lieu of county-level inventories, I will be relying on other sources, namely databased herbarium specimens, my own field observations, and verified iNaturalist records to build checklists for each of these counties. Special attention is needed in Clinton County, especially in its northern portion where driftless topography is present. Additionally, more attention along the Wapsipinicon River in this county as well as adjacent counties is needed. These areas are the most likely to turn up new records of species known from just outside the region. Mercer County is in great need of botanizing, especially along the Mississippi and Edwards rivers. It is possible that southern species not currently known from the other counties may be present there. Finally, Whiteside County has a surprisingly low number of floristic records. The loess upland woods and remnant wetlands inland from the Mississippi are much deserving of botanical attention.
Other Important Notes
Excluded Records from Guldner’s Flora
The Vascular Plants of Scott and Muscatine Counties is, without a doubt, the most important work on the plants of the Quad Cities Region to date. Guldner, however, included cultivated species, many of which he collected from private and public gardens in Scott County. This methodology is atypical for floristic works of this type, and it differs from my intention for the Flora of the Quad Cities Region project which is to include only native and naturalized taxa that occur spontaneously. Due to this difference, I am excluding all reports from Guldner’s work where he only knew the species from cultivation.
Guldner’s work includes a small number of doubtful records and scientific names that are very challenging to synonymize. For the most part, these have been excluded, as well. There are minor typos throughout his book, and the correct spelling has been assumed in nearly all cases.
Raymond Dobbs also included, albeit a small number, of cultivated plants which are excluded from this list, as well.
The Flora of Scott and Muscatine Counties by Reppert, Barnes, and Miller (1900)
I have not database and incorporated the work completed by Reppert et al. (1900) primarily because Guldner integrated their records into his work. For sake of completeness, integration of their original records into this project may be undertaken in the future.
Ongoing Work and Future Objectives
Field Work
2025 marks the fourth consecutive year that I have actively botanized in the region, and continued field work lies at the heart of this project. To date, I have completed a relatively thorough investigation of Rock Island County, as well as the area along and bordering the Mississippi River between Muscatine and Clinton. In the coming seasons, I aim to spend more time in the under botanized areas mentioned above and other areas I have yet to explore. There are many historical records that need to be sought out, and their continued existence confirmed.
Website and Online Database
The long-term goal is to develop a searchable online database of plant species from the region. Each taxon will have a page that includes its distribution, habitat descriptions, photos, and typical associates. This will require additional financial and technical support.
Flora of the Quad Cities Region 