This article was originally published in 2019, but has been updated to include control options and additional resources. As we’re entering fig buttercup season, everyone will want to keep an eye out for this aggressive invasive!
by Andrea Laine, EMGV
A fellow Extension master gardener recently brought this cheerful-looking plant to my attention. Its common names are lesser celandine or fig buttercup. (Scientific name is Ficaria verna and was formerly Ranunculus ficaria.) She spotted it blooming in March on the Ellerbe Creek and also beside the Eno River at Penny’s Bend, an area known for extraordinary native flora. However, this plant is not native to the the Southeast nor even to North America. It is an aggressive, exotic, invasive species that threatens to displace our beloved native spring ephemerals.
Lesser celandine is a herbaceous perennial that emerges earlier than most native species. Additional identifying characteristics are:
- A basal rosette of dark kidney- or heart-shaped leaves;
- A bright yellow flower blooms on a single stalk that rises eight to nine inches above the leaves;
- Small bulbets borne in the leaf axis.
- Abundant fig-shaped tubers form along the roots; Even when separated from the parent plant, the tubers can produce a new plant.
- An overall tight low-growing mat that rapidly chokes out neighboring seedlings.
- It grows best in moist, shady soils like those in a river’s floodplain.
Supporting its rapid growth are three ways the plant can reproduce: by the tubers/root fragments, by seeds, or by the bulbets. Any of these methods can form a new plant in the vicinity of the parent or be carried downstream to begin colonizing in a new location.
Complicating matters of identification is that lesser celandine looks very much like marsh marigold (Caltha palustris) which is native in North Carolina and enjoys similar growing conditions. The two can be distinguished by the number of petals on the flower (typically eight for lesser celandine and five for marsh marigold) and the appearance of the leaf margin (smooth for lesser celandine and serrated for marsh marigold).
Like many invasive plants, this one was introduced commercially as an ornamental plant. It became popular in the Northeast, but its status is in transition. It appears on the The North Carolina Native Plant Society invasive plants list as a “significant threat.” Yet it is absent from the USDA Natural Resources Conservation Service’s list of noxious weeds in North Carolina. That list reports that it is absent/unreported in N.C. and S.C., however according to the South Carolina Native Plant Society, it is banned in S.C.
Exotic plant species that essentially grow too well in an area negatively impact a local ecosystem by crowding out the native plants. Insects, birds and animals native to the area depend upon native plants for nutritional sustenance and preferred habitat. Well-known patches of lesser celandine that are large enough to disrupt native habitat can be found in the Duke Park area, Sandy Creek watershed, and around some tributaries draining to Eno River (including the Eno Commons area).
If your property offers adequate growing conditions for lesser celandine or marsh marigold, keep an eye out for an expanding patch of low-growing plants with bright yellow flowers. It’s important to remove lesser celandine when you find it. Lesser celandine is best targeted when it’s actively growing in February and March. While small patches can be taken out by hand, a systemic herbicide is recommended for larger patches because it targets the whole plant and minimizes soil disturbance (click here for more information on controlling lesser celandine). Control often takes multiple seasons.
If you locate it on land you do not own, say while you are enjoying a public park or private nature preserve, you may bring it to the property owner’s attention, but you do not have the right to remove it. The patch recently found at Penny’s Bend Nature Preserve has been removed, and the patch on Ellerbe Creek was sprayed by a licensed herbicide applicator. It was linked to a larger patch growing behind a house just a couple blocks upstream on a feeder creek.
Sources & Further Reading
NCSU suggests planting Geum as an alternative: https://plants.ces.ncsu.edu/plants/all/geum-spp/
About Marsh Marigold: https://plants.ces.ncsu.edu/plants/all/caltha-palustris/
How the North Carolina Botanical Garden defines “invasive exotic species: http://ncbg.unc.edu/exotic-plant-policy/
About Penny’s Bend Nature Preserve: http://www.enoriver.org/what-we-protect/parks/pennys-bend/