Panicledleaf Ticktrefoil, Panicled-Leaf Tick Trefoil (or various other combinations), Tall Tick Trefoil, Narrow-Leaf Ticktrefoil (Tick Trefoil, Panicled Tickclover
Synonyms of Desmodium paniculatum (16) (Updated 3-6-21): Desmodium dichromum Shinners, Desmodium paniculatum var. angustifolium Torr. & A.Gray, Desmodium paniculatum var. epetiolatum B.G.Schub., Desmodium paniculatum var. pubens Torr. & A.Gray, Desmodium paniculatum var. typicum B.G.Schub., Desmodium pubens (Torr. & A.Gray) Young ex S.Watson, Hedysarum paniculatum L., Hedysarum paniculatum var. obtusum Desv., Meibomia chapmanii (Britton) Small, Meibomia paniculata (L.) Kuntze, Meibomia paniculata var. angustifolia (Torr. & A.Gray) Vail, Meibomia paniculata var. chapmanii Britton, Meibomia paniculata var. obtusa (Desv.) Schindl., Meibomia paniculata var. pubens (Torr. & A.Gray) Vail, Meibomia pubens (Torr. & A.Gray) Rydb., Pleurolobus paniculatus (DC.) MacMill.
Desmodium paniculatum (L.) DC. is the correct and accepted name for this species of Desmodium. It was named and described as such by Augustin Pyramus de Candolle in Prodromus Systematis Naturalis Regni Vegetabilis in 1825. It was first named and described as Hedysarum paniculatum by Carl von Linnaeus in the second volume of the first edition of Species Plantarum in 1753.
Desmodium perplexum B.G.Schub. is the other possibility for this species of Tick Trefoil. It was named and described as such by Bernice Giduz Schubert in Rhodora in 1950.
The genus, Desmodium Desv., was named and described as such by Nicaise Auguste Desvaux in Journal de Botanique in 1813.
Plants of the World Online lists 186 accepted species in the Desmodium genus (as of 3-6-21 when I last updated this page). Desmodium is a member of the plant family Fabaceae family along with 770 genera. Those numbers could change as updates are made (and likely will).
The map above from the USDA Plants Database shows the distribution of Desmodium paniculatum in North America. Normally I use a map from Plants of the World Online, but it didn’t include several states in the United States or the provinces in Canada. Apparently, this is a native North American species and hasn’ been introduced to other countries. Species range for D. perplexum is similar but doesn’t include provinces in Canada.
Species identification is difficult and often depends on close analysis of the seedpods. The plants in this genus vary, with habits ranging from prostrate (lying on the ground) to erect stems. Flowers are usually in terminal racemes; pink, violet, or white; having the characteristic form of pea flowers. The blooming period is July–September, varying depending on species. Leaves are alternate, 3-divided, varying in shape and length of petiole, the lateral (side) leaflets usually on very short stems with the center leaflet on a longer stem. Fruit in distinct papery pods, which break up into 1-seeded segments that are dispersed by animals, including people.
THERE ARE SEVERAL LINKS AT THE BOTTOM OF THE PAGE FOR FURTHER READING AND BETTER POSITIVE ID.
Desmodium paniculatum, and its relatives, appear to be a nice plant when flowering. However, when they go to seed they are definitely one you love to hate. So many times while walking through vegetation to take photos at the end of summer I have been bombarded with their seed stuck to my pants and boots. I originally thought they were Desmodium perplexum (Perplexing Tick Trefoil) but mainly because I couldn’t tell the difference between the two. So, I suppose I was perplexed… How sure am I that it is D. paniculatum instead of D. perplexum? Not 100%. I will no doubt have to change back to D. perplexum…
Steyermark’s Flora of Missouri (Volume 3) lists 17 species of Desmodium in Missouri, 8 of which have been identified in Pettis and Henry Counties. I include Henry County because it is across the street. Johnson and Benton Counties are also fairly close. Of the eight species that “could” grow on my farm, they are likely either D. paniculatum or D. perplexum. Information suggests several species, including D. perplexum, are part of the Desmodium paniculatum Compex. To make identifying several species more difficult, it is believed that several species have hybridized…
Desmodium perplexum leaves are sort of more broadly oval while D. paniculatum leaves are narrower. Well, two leaves are narrowly ovate while one is broadly-ovate… The leaves are fuzzy feeling, slightly pubescent, for both species. The stems of D. paniculatum are slightly more hairy than D. perplexum… I tried to get close-up photos of the stems but they came out blurry. The Missouri Plants website only has information about D. paniculatum. Somewhere I saw photos comparing the stems but I can’t remember where. GEEZ!
All species of Desmodium, in Missouri at least, have similar flowers. Some species flowers are said to be larger and may have other special distinguishing features. I am not going to get into all the “technical” botanical terminology. There are several links below that provide that information.
Probably the worse thing about Desmodium species is their velcro-like seed pods. I have learned to avoid walking into areas where I could come out plastered…
I usually wind up having them on my pants anyway.
I read where Desmodium paniculatum flowers have a floral scent but D. perplexum has no scent. Hmmm… I will have to give the flowers a whiff in 2021.
Well, these leaves look more elongated like D. paniculatum. Maybe I have both species…
Hmmm… After trying to figure out the correct ID this species here for several years, switching from one to another, I am still somewhat confused. The drag and drop feature to help ID plants on iNaturalist suggests D. perplexum… Then, when I uploaded the above photo it just said Desmodium. The first suggestion was D. paniculatum and perplexum wasn’t on the list… I added observations for three dates, so we’ll see what other members have to say. I may have to change the captions and other information once AGAIN…
I have enjoyed photographing and learning about the many wildflowers growing on the farm and other areas. I have grown over 500 different plants and most have pages listed on the right side of the blog. 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 horticulturalist I contact if I cannot figure them out. Wildflowers can be somewhat variable from location to location, so sometimes it gets 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 provide much more information. 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. You can also send an email to me at firstname.lastname@example.org. I would enjoy hearing from you.