Perfoliate Tinker’s Weed, Fever Root, Wild Coffee, Feverwort, Common Horse Gentian, Late Horse Genetian
Synonyms of Triosteum perfoliatum (4) (Updated on 5-23-21 from Plants of the World Online): Karpaton hastatum Raf., Triosteum connatum Raf., Triosteum majus Michx., Triosteum obovatum Raf.
Triosteum perfoliatum L. is the correct and accepted scientific name for this species. The genus and species were both named and described as such by Carl von Linnaeus in the first volume of the first edition of Species Plantarum in 1753.
Plants of the World Online lists 6 species in the Triosteum genus (as of 5-23-21 when I last updated this page). It is a member of the plant family Caprifoliaceae with a total of 33 genera. Those numbers could change periodically as updates are made by POWO.
The above distribution map for Triosteum perfoliatum is from the USDA Plants Database. The map on Plants of the World Online doesn’t show near the range but maybe it will when updates are made. The species is a North American native and has not been introduced in other countries.
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. Data from some maps come from old herbarium samples and the species may not even exist in some states now. The species may have been observed in one or two sites in some states. With iNaturalist, you get current observations as long as the species has been correctly identified and is research grade.
THERE ARE SEVERAL LINKS AT THE BOTTOM OF THE PAGE FOR FURTHER READING AND TO HELP WITH A BETTER POSITIVE ID.
I found this neat species growing in the woods on a friend’s farm while wildflower hunting on May 10 (2020). I didn’t know what it was so I took LOTS of photos so I could make a positive ID. Later on, I uploaded the photos on iNaturalist and found out it was Triosteum perfoliatum. Common names include Perfoliate Tinker’s Weed, Fever Root, Wild Coffee, Feverwort.
The Triosteum perfoliatum is a perennial wildflower that grows up to 3 1/2 feet tall. Its strong stems have short average length soft hair. Some information says the stems are unbranched while others say they could branch out at the base.
The species produces 1-5 flowers, which are sessile (no petioles) from the leaf axils (where the leaves join the stems). Each flower produces a narrow tube-shaped corolla. I am not even going to confuse myself trying to write a description about the flowers in layman’s terms. You can read a more technical botanical description on Missouri Plants or one that is easier to understand on Illinois Wildflowers. Well, there are several good websites with great photos and descriptions listed at the bottom of the page.
The Triosteum perfoliatum produces flowers from May through July.
This species has amazing leaves. They grow in pairs opposite each other which grow at a 90° angle from the pair above and below. The longest leaves grow up to at least 8” long x 4” wide. The shape of the leaves is kind of weird and hard to explain… They are kind of broadly lance-shaped with a fairly pointed tip, they narrow somewhat then get wider toward the stem. The species name perfoliatum comes from the way some or all of its broadly winged leaves join together at the base and surround the stem. I think plants like that are really neat! The upper surface of the leaves can be hairless (glabrous) to slightly hairy while the undersurface I kind of whitish and covered with fine hair (pubescent).
Now, that is just neat any way you look at it… It looks like a single leaf with a stem running through the middle.
The leaves have a very prominent midrib (or midvein).
The undersides of the leaves have kind of a whitish cast because of the short, soft hair.
The oddly shaped leaves grow in an opposite manner, meaning one across from another. With this species, the pairs above and below grow at a 90° angle from each other.
Several species of bees feed on the nectar produced by its flowers and a few species of caterpillars feed on the leaves.
The fruits of this plant have been used as a coffee substitute.
I didn’t get to go back into the woods to take photos of the fruit and seeds in 2020, but hopefully, I can do that in 2021.
Triosteum perfoliatum was a very neat find and one that will keep me going back to its area of the woods.
I have enjoyed photographing and learning about the many wildflowers growing on the farm and other areas. My farm is 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 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. 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. You can also send an email to me at firstname.lastname@example.org. 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)
WORLD FLORA ONLINE (GENUS/SPECIES)
USDA PLANTS DATABASE
MISSOURI DEPARTMENT OF CONSERVATION
KANSAS WILDFLOWERS AND GRASSES
PFAF (PLANTS FOR A FUTURE)
FRIENDS OF THE WILDFLOWER GARDEN
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 (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. 🙂