False Rue Anemone
Synonym: Isopyrum biternatum (Raf.) Torr. & A.Gray
Enemion biternatum Raf. is supposedly the correct and accepted scientific name once again for the False Rue Anemone. The genus and species were described as such by Constantine Samuel Rafinesque in Journal de Physique in 1820. It was renamed Isopyrum biternatum by John Torrey and Asa Gray in A Flora of North America in 1840 and is now considered a synonym. I noticed a few websites and databases are still using Isopyrum biternatum. It is difficult for many to keep up with name changes.
Plants of the World Online lists 6 species in the Enemion genus and 4 in the Isopyrum genus (as of 5-27-20 when I am updating this page). They are members of the Ranunculaceae Family with a total of 53 genera. Those numbers could change periodically as updates are made.
Note: I noticed Plants of the World Online, World Flora Online, and The Plant List are incorrectly using Enemion biternatum (Torr. & A.Gray) Raf. as the accepted name. I sent an email to the senior content editor of the Royal Botanical Gardens-Kew on 5-27-20 and he agreed it was incorrect. He thanked me and said he took care of it. So, at some point, the accepted name will appear as Enemion biternatum Raf. and the synonym should be Isopyrum biternatum (Raf.) Torrey & A.Gray (which also appears incorrectly). The name on The Plant List won’t change because it hasn’t been maintained since 2013. World Flora Online uploaded their data from The Plant List without updating THOUSANDS of name changes. I think World Flora Online is going to work with POWO to upload correct scientific names but probably restrictions due to COVID-19 have delayed the changes. The USDA Plants Database has it correct already.
The above distribution map for Enemion biternatum is from Plants of the World Online. The map on the USDA Plants Database for North America is the same. A few states and Ontario, Canada one have this species in a few areas and it is listed as an endangered or threatened species.
There are several links at the bottom of the page for further reading and to assist with a better positive ID.
I observed only a few small colonies of Enemion biternatum in the woods along the East Fork Tebo Creek on a friend’s property on April 27, 2020. It’s most widely used common name is False Rue Anemone and it is a member of the Ranunculaceae Family. The plants are fairly short and very easy to pass over when not in flower. Enemion biternatum is a perennial and is considered a spring ephemeral. This means after flowering in very early spring the plants will go dormant after setting seed. This is one of the earlier flowering plants in the woods, blooming before the trees leaf out. Plants then emerge again in the fall and remain evergreen over the winter. Plants may produce small tubers.
This perennial wildflower was formerly best known as Isopyrum biternatum (eye-so-PYE-rum by-TER-nat-um).
Its leaves grow in an alternate fashion, are ternately divided or trifoliate, and glabrous (hairless). The basal leaves have longer petioles (stems) than the upper leaves. Leaflets are broadly lanceolate to ovate, 2-3 lobed or parted, and sometimes have shallow notches at the tips. Information says leaves are 2-3 times compound and 3 parted…
Flowering stems, 4-16″ long, emerge from leaf axils along the stem as well as at the top of the plant. Flowering stems also produce leaves. There are a pair of rounded stipules where the flower stalk and leaf stalk join.
Next spring I hope to take more photos of various features. I was unfamiliar with this species when I made my first observation so I didn’t know about its feature characteristics.
Plants produce 1-4 flowers per flowering stem. At first glance, anyone would think this is a five-petaled flower (some may have six but usually only five). However, the petals are actually petal-like sepals and not petals at all. The flowers produce pollen but no nectar. Flowers have 25 to 50 stamens with yellow anthers. These arise from under the green erect carpels that are 3 to 6 in number, each having a short style.
This species is often confused with Thalictrum thalictroides which is the true Rue Anemone.
Hopefully, I will be able to find these plants again in the spring of 2021. As I am writing this page on May 28, the underbrush and other plants are getting taller making the earlier, smaller species harder to find.
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
NOTE: Plants of the World Online is the most up-to-date database. It is very hard for some to keep with name changes these days so you may find a few discrepancies between the websites. Just be patient. Hopefully, someday they will be in harmony. 🙂