Illinois Tick-Trefoil

Desmodium illinoense

des-MOH-dee-um  il-lin-oh-EN-see

Desmodium illinoense A.Gray is the accepted scientific name for this species of Desmodium. It was named and described as such by Asa Gray in Proceedings of the American Academy of Arts and Sciences in 1870.

The genus, Desmodium Desv., was named and described as such by Nicaise Auguste Desvaux in Journal de Botanique in 1813. 

As of 7-15-26 when this page was written, Plants of the World Online lists 178 species in the Desmodium genus. It is a member of the plant family Fabaceae with 805 genera. Those numbers could change as updates are made on POWO.

The above distribution map for Desmodium illinoense is from Flora of North America. Areas in green are where the species is native. The map on the USDA Plants Database is somewhat different. No map is perfect, but they do give a general idea.

The map on iNaturalist shows where members have made observations. Anyone can join and it is a great website to confirm and share your observations. The maps on iNaturalist are continually updated as members post new observations. I post all my observations on iNaturalist.

THERE ARE SEVERAL LINKS AT THE BOTTOM OF THE PAGE FOR FURTHER READING AND TO HELP WITH A POSITIVE ID.

I was invited by a friend to visit a private prairie east of town in May 2025 and it was incredible. Then we went to Drover’s Prairie and the Lordi Marker Prairie on April 19 in 2026 which was also incredible. I then went to the Friendly Prairie and back to Drover’s Prairie on June 22 where I found even more new to me species. While at the Lordi Marker Prairie on 6-8, I ran across this species I wasn’t familiar with although looked suspicious. I took several photos which I uploaded on iNaturalist when I returned home. The name Desmodium illinoense was suggested, and after a little research, it appears iNaturalist was right again… I took more photos at Drover’s  and the Friendly Prairie on 6-22-26.

Normally, Desmodium species are one of those species you love to hate because of the dried seed pods that stick to your clothes. This time was different because it was a new to me species…

I was pretty sure it was a Desmodium species because its leaves looked like the plants growing on the farm. The pink flowers were also a good sign.

 

Yep, the flowers sure looked like Desmodium flowers…

Here is a good photo of the height the single stems get. That was odd to me because the Desmodium paniculatum or D. perplexum (whichever one they are) have several flowering stems per plant and they are not tall. Just a mound you try to avoid when the seed pods turn brown.

 

 

No mistaking it for being a member of the plant family Fabaceae either.

They still produce way too many seed pods!

I will come back later and write descriptions, I just wanted to go ahead and get the photos online. There are several links at the bottom of the page with useful information and great descriptions.

I will continue going back to the prairies, and probably a few others, to take more photos.

I live on the family farm in Windsor, Missouri in Pettis County (Henry County is across the street, and Benton and Johnson aren’t far away). I have grown over 500 different plants and identified over 250 species of wildflowers (most have pages listed on the right side of the page). I am not an expert, botanist, or horticulturalist. I just like growing, photographing, and writing about my experience. I rely on several websites for ID and a few horticulturalists I contact if I cannot figure them out. Wildflowers can be variable from location to location, so that can be a bit confusing. If you see I have made an error, please let me know so I can correct what I have written.

I hope you found this page useful and be sure to check the links below for more information. They were written by experts and they have provided much more information. Some sites may not be up-to-date but they are always a work in progress. If you can, I would appreciate it if you would click on the “Like” below and leave a comment. It helps us bloggers stay motivated. I would enjoy hearing from you especially if you notice something is a bit whacky.

FOR FURTHER READING:
PLANTS OF THE WORLD ONLINE (GENUS/SPECIES)
INTERNATIONAL PLANT NAMES INDEX (GENUS/SPECIES)
TROPICOS (GENUS/SPECIES)
FLORA OF MISSOURI (GENUS/SPECIES)
FLORA OF NORTH AMERICA (GENUS/SPECIES)
WORLD FLORA ONLINE (GENUS/SPECIES)
WIKIPEDIA (GENUS/SPECIES)
USDA PLANTS DATABASE
iNATURALIST
MISSOURI BOTANICAL GARDEN
WILDFLOWER SEARCH
ILLINOIS WILDFLOWERS
KANSAS NATIVE PLANTS
KANSAS WILDFLOWERS AND GRASSES
LADY BIRD JOHNSON WILDFLOWER CENTER
MINNESOTA WILDFLOWERS
SEINet

NOTE: The data (figures, maps, accepted names, etc.) may not match on these websites. It depends on when and how they make updates and when their sources make updates. Some websites have hundreds and even many thousands of species to keep up with. Accepted scientific names change periodically and it can be hard to keep with as well. Some of the links may use a name that is a synonym on other sites. In my opinion, Plants of the World Online by Kew is one of the most reliable and up-to-date plant databases and they make updates regularly. I make updates “at least” once a year and when I write new pages or add new photos but I do get behind. We are all a work in progress. 🙂