Lesser Celandine (Ficaria verna (previously Ranunculus ficaria)) belongs to the buttercup family, Ranunculaceae, and is sometimes called "fig buttercup." The “buttercup” describes the bright yellow flowers, and the “fig” refers to the shape of the underground tubers.
The bright yellow buttercup flowers are now revealing lesser celandine infestations throughout Ohio and generating phone calls and e-mails to Extension offices from landowners seeking management options. Unfortunately, there are no quick-fix remedies for this highly invasive non-native perennial, particularly for heavy infestations.
Lesser celandine is included on the Ohio Department of Agriculture's List of Invasive Plants. Plants on the list were prohibited from being sold or distributed in Ohio. You can see this list by clicking on the hotlink below:
Background Information
Lesser celandine is native to Europe, northern Africa, western Asia, and Siberia. It is believed to have been first introduced to North America as an ornamental in the mid-1800s and escapes were reported in Pennsylvania in 1867.
The shiny dark green heart-shaped leaves sit atop fleshy, white, tightly clustered leaf stalks. New leaves are noticeably mottled with light and dark green patches.
Glossy, bright yellow to butter-yellow flowers that are about 1" in diameter rise singly on stalks slightly above the foliage. Pollinators including western (European) honey bees (Apis mellifera) may be observed visiting the flowers; however, the numbers are usually underwhelming.
It’s a small wonder that lesser celandine was imported for its ornamental value. The overall effect of a massive colony is a magical-looking dark green carpet speckled with flecks of bright yellow. It’s a beautiful sight unless you consider that the magic carpet rolls over native spring wildflowers, particularly spring ephemerals. Although lesser celandine plants seldom rise more than 4 – 5" above the soil, they have dense root systems, and plants grow together to form mat-like impenetrable canopies.
I've observed lesser celandine rolling over Trillium (Trillium spp.), mayapple (Podophyllum peltatum), cutleaf toothwort (Cardamine concatenate), Dutchman's breeches (Dicentra cucullaria), and Virginia springbeauty (Claytonia virginica).
Lesser celandine was originally associated with moist soils near streams or around spring seeps, as well as in dense shade in forested areas or beneath trees. Dense colonies continue to be found in those locations.
However, lush aggregations are now commonly found blanketing well-drained hillsides and hilltops in Ohio. Plants may also creep into turfgrass.
The variability in sites where plants thrive may be associated with genetic diversity within the species. Lesser celandine hails from a wide geographical range. The taxonomy of this Eurasian native has long been debated with some sources indicating there are subspecies, varieties, and geographical genotypes (provenances). Part of the confusion stems from a seasonal variation in flower parts with early-flowering plants having more flower parts compared to late-flowering plants.
Don’t confuse our native Marsh Marigold (Caltha palustris) with lesser celandine, or vice versa. Both are spring ephemerals that belong to the buttercup family with plants sporting similar-looking yellow flowers. However, lesser celandine flowers have 3 green sepals and 7–12 yellow to faded yellow petals. Marsh marigold flowers have 5–9 yellow petal-like sepals and the leaves are much larger. Of course, as its common name implies, marsh marigold does not wander far from wet environs.
Now You See It, Now You Don’t
Lesser celandine has a perennial life cycle but is considered a “spring ephemeral” owing to its now you see it, now you don’t behavior. The vast majority of the year is spent as tubers concealed in the soil out of sight, out of mind. When spring rolls around, plants spring forth rapidly to complete the above-ground portion of the life cycle.
The deep green foliage functions to solar-charge a stockpile of underground tubers. The energy cycle reverses the following spring with the tubers supporting new leaf growth through vegetative reproduction. Of course, the tubers can also serve as a foundation for new infestations if they are moved around in contaminated soil. Much like potatoes, even a small portion of a cut tuber can give rise to a new plant.
The production of football-shaped protuberances called bulbils represents another form of vegetative reproduction practiced by lesser celandine. A close examination of leaf axils near the base of mature plants later this spring will reveal these odd structures. Bulbils can give rise to new plants and are perfectly suited for being picked up in the dewclaws of deer. Indeed, deer have been implicated as a major mover of lesser celandine with new plants often sprouting on or along deer trails.
Lesser celandine may also reproduce sexually; however, I've never observed seed production in southwest Ohio. Lesser celandine plants come in three flavors based on the number of chromosomes with diploid plants having two sets of chromosomes, triploid three sets, and tetraploid four sets. All produce flowers, but whether or not flowers lead to seeds depends on who’s crossing.
Although I’ve never found seeds on lesser celandine plants, this doesn’t mean plants do not produce seeds in my part of the state or elsewhere in Ohio. Indeed, seed production may account for some of the rapid spread of lesser celandine observed in various parts of the state. However, I do not doubt that plants in southern Ohio reproduce vegetatively.
Lesser celandine's final secret weapon in its survival and spread is its radical ephemeral nature. Plants collapse and disappear from view in late spring to early summer depending on environmental conditions. It’s amazing how rapidly a broad expanse of lesser celandine can completely vanish. Unfortunately, this natural plant collapse may lead some to believe that an herbicide application was highly effective. However, the weed is not gone; it's just biding its time in the form of recharged tubers that will support ever-expanding colonies next season.
Management
Unfortunately, although lesser celandine is rapidly becoming the scourge of spring in Ohio and elsewhere in North America, non-biased, research-based management data involving both cultural and herbicidal options appear to be almost non-existent in the published literature. The vast majority of reported management options are based on anecdotal evidence.
Various online recommendations for eliminating lesser celandine by digging and destroying plants are in my opinion based on shaky ground. It’s been my anecdotal experience that it can be difficult if not impossible to physically remove all the tubers from the soil. Removal efforts usually morph into a frustrating ongoing game of whack-a-mole, even with small colonies.
The only published herbicide trials that I’m aware of were conducted in a wooded area Wolf Trap National Park in Virginia and published in 2017 (see Selected References below). The applications consisted of glyphosate (2.5% by volume) mixed with a nonionic surfactant (0.5% by volume) made 2 years in a row targeting the early flowering and 50% flowering stages. The efficacy rate was 90% and 95% control, respectively.
It's important to note the study was conducted on heavy, established infestations. Two key takeaways are the application timing and the need for repeat applications.
Waiting until plants are flowering to apply glyphosate is consistent with recommendations targeting other plants. Glyphosate’s systemic activity involves translocation of the herbicide downward to wreak havoc on roots and carbohydrate storage structures. Applications made too early require the herbicide to move against the tide as carbohydrates flow upward in support of plant growth and flower development.
The study also highlights the reality that heavy lesser celandine infestations are unlikely to be suppressed in one season with a single application. Thus, it’s important to identify developing colonies early and to act before infestations become dense.
It’s also important to remember that lesser celandine readily spreads from heavy infestations. An eradication program can be quickly undone with plants spreading from nearby infestations. Successful long-term management programs may require cooperation from owners of contiguous properties.
Lesser celandine is far easier to manage in turfgrass compared to other locations. Although online herbicidal recommendations may be based on anecdotal evidence, I’ve observed the successful elimination of infestations in turfgrass through a combination of mowing and applications of selective post-emergent herbicides labeled for use on turfgrass.
Turfgrass herbicides reported to be effective against lesser celandine include products that include 2,4-D, MCPA, MCPP, dicamba, and triclopyr. It is generally recommended to use products that contain at least 2 of these herbicides. Products based on metsulfuron (e.g., Quali-Pro MSM Turf Herbicide) and sulfentrazone (e.g., Dismiss) have also been observed to suppress lesser celandine in turfgrass.
Lesser celandine management in flower beds may require delayed planting of annuals so lesser celandine plants can be targeted with a non-residual, non-selective, post-emergent herbicide such as glyphosate. However, eliminating lesser celandine in annual bulb beds is problematic and may require soil removal and replacement.
Of course, as with making any pesticide application, applicators must read and follow label directions. This is particularly important when using turfgrass herbicides near trees, other woody ornamentals, herbaceous perennials, and annuals.
NOTE: The original active ingredient in Roundup® was glyphosate. Indeed, the two became synonymous. However, Roundup® products now contain a wide range of active ingredients with some not containing glyphosate. Glyphosate is a non-selective herbicide meaning it kills a wide range of plants. Some Roundup® products now have selective herbicides meaning they will only kill certain plants. However, the active ingredient(s) may not be safe to use around certain plants. For example, triclopyr is a selective herbicide that does not kill grass, but it is not safe to apply beneath trees or other woody ornamental. This is why it’s critical to read and follow product label directions!
Selected References (listed by Publication Date)
Post, A. R., A. Krings, W. Wall, and J. C. Neal. 2009. Introduced lesser celandine (Ranunculus ficaria, Ranunculaceae) and its putative subspecies in the United States: a morphometric analysis. J. Bot. Res. Inst. Texas (formerly SIDA) 3(1):193-209.
https://www.jstor.org/stable/41972152
Frey, M.N. and Schmit, J.P., 2017. Early-Season Treatment of Fig Buttercup (Ranunculus ficaria). Invasive plant science and management, 10(2), pp.191-200.
Bellian, R., 2020. Investigating the Effects of Temperature on Lesser Celandine. The Downtown Review, 6(2), p.1.
https://engagedscholarship.csuohio.edu/cgi/viewcontent.cgi?article=1093&context=tdr
Knapp, L.S.P., Coyle, D.R., Dey, D.C., Fraser, J.S., Hutchinson, T., Jenkins, M.A., Kern, C.C., Knapp, B.O., Maddox, D., Pinchot, C. and Wang, G.G., 2023. Invasive plant management in eastern North American Forests: A systematic review. Forest Ecology and Management, 550, p.121517.
www.fs.usda.gov/nrs/pubs/jrnl/2023/nrs_2023_pile-knapp_001.pdf
Triquet, C., Wezel, A., Tolon, V. and Ferrer, A., 2024. Undestroyed winter cover crop strips support wild bee abundance and diversity in intensive cropping systems. Biodiversity and Conservation, 33(1), pp.179-204.
https://link.springer.com/article/10.1007/s10531-023-02741-5