Desmodium paniculatum/Desmodium perplexum (Panicledleaf/Perplexing Tick Trefoil, ETC., ETC…)

Desmodium paniculatum {Panicled-Leaf Tick Trefoil) on 9-6-18, #503-16.

Panicledleaf Ticktrefoil, Panicled-Leaf Tick Trefoil (or various other combinations), Tall Tick Trefoil, Narrow-Leaf Ticktrefoil (Tick Trefoil, Panicled Tickclover

Desmodium paniculatum

des-MOH-dee-um  pan-ick-yoo-LAY-tum

OR MAYBE

Desmodium perplexum

des-MOH-dee-um   per-PLEKS-um

Synonyms of Desmodium paniculatum (16) (Updated 5-11-21): 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 184 accepted species in the Desmodium genus (as of 5-11-21 when I last updated this page). Desmodium is a member of the plant family Fabaceae family along with 767 genera. Those numbers could change as updates are made on POWO (and likely will). 

Distribution map for Desmodium paniculatum from the USDA Plants Database. Published on the internet at https://plants.sc.egov.usda.gov/home. Retrieved on May 11, 2021.

The above map for Desmodium paniculatum is from the USDA Plants Database. The map on Plants of the World Online was not up to date… They use data for North America from Flora of North America and that site does not have the plant family Fabaceae included yet. POWO is supposed to start using data from the USDA for families not included in FNA later in 2021.

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.

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 {Panicled-Leaf Tick Trefoil) on 9-6-18, #503-17.

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 Complex. To make identifying several species more difficult, it is believed that several species have hybridized…

Desmodium paniculatum {Panicled-Leaf Tick Trefoil) on 9-6-18, #503-18.

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!

Desmodium paniculatum {Panicled-Leaf Tick Trefoil) on 9-6-18, #503-19.

All species of Desmodium, in Missouri at least, have similar flowers. The flowers of some species 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.

Desmodium paniculatum {Panicled-Leaf Tick Trefoil) on 9-8-18, #504-25.

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…

Desmodium paniculatum {Panicled-Leaf Tick Trefoil) on 9-8-18, #504-26.

I usually wind up having them on my pants anyway.

Desmodium paniculatum (Panicled-Leaf Tick Trefoil) on 8-31-19, #619-7.

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.

Desmodium paniculatum (Panicled-Leaf Tick Trefoil) on 8-31-19, #619-8.

Well, these leaves look more elongated like D. paniculatum. Maybe I have both species…

Desmodium paniculatum (Panicled-Leaf Tick Trefoil) on 9-7-19, #625-15.

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…

<<<<2021>>>>

Desmodium paniculatum ? on 9-28-21, #836-11.

I hadn’t taken any photos of the Desmodium for a while because I am not really that thrilled about them. No one on iNaturalist agreed or suggested an ID because of the two species that are so much alike. I did help another member decide his observation was likely Desmodium paniculatum even thoug the leaves on the plant he photographed were a bit narrower… We came to the conclusion it is a variable species and the leaves can vary in size and shape. It is highly likely what I have on the farm is Desmodium paniculatum, but who can really be sure? Maybe I should just choose one and be happy. 🙂 Well, not necessarily happy when it comes to this species.

Desmodium paniculatum ? on 10-12-21

I had been fairly fortunate at avoiding getting so many of their seeds on my pants, but I also started wearing my Dry Shod boots to keep so many off my pants. On October 12 I walked through the middle of the south hayfield where there wasn’t so many of these darn things. BUT, I was on a mission to photograph a particular plant on the edge of the hayfield which I had to wade through blackberry briars to get to. When I walked out of the briars, I looked down at my boots. GEEZ!!! I should wear my old rubber boots! After that there was no point in trying to avoid them. When I walked back to the house, I stopped to pick the seeds off of my pants then sat on an old telephone pole to get them off of my boots. I took off one boot and removed them and thought how glad I was I didn’t have any of “those other” sticktights on my boots. You know, the ones from Torilis arvensis or Torilis japonica (Hedge Parsley). I took off the other boot and put my foot right on a cluster of Hedge Parsley seeds. Then I had a mess on my sock! I hadn’t noticed them before I sat down!

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 thebelmontrooster@yahoo.com. I would enjoy hearing from you.

FOR FURTHER READING:
PLANTS OF THE WORLD ONLINE (GENUS/SPECIES)
INTERNATIONAL PLANT NAMES INDEX (GENUS/SPECIES)
TROPICOS (GENUS/SPECIES)

WORLD FLORA ONLINE (GENUS/SPECIES)
WIKIPEDIA (GENUS/SPECIES)
DAVE’S GARDEN
MISSOURI PLANTS
iNATURALIST.ORG
WILDFLOWERSEARCH.ORG
USDA PLANTS DATABASE
USDA PLANT GUIDE
ILLINOIS WILDFLOWERS
LADY BIRD JOHNSON WILDFLOWER CENTER
PFAF (PLANTS FOR A FUTURE)
GO BOTANY
KANSAS WILDFLOWERS AND GRASSES
FLORA FINDER

NOTE: The figures may not match on these websites. It depends on when and how they make updates and when their sources make updates (and if they update their sources or even read what they say). 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 the most reliable and up-to-date plant database and they make updates on a regular basis. 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. 🙂

 

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