Photographer: Leslie J. Mehrhoff Affiliation: University of Connecticut Source: www.bugwood.org Copyright:CC BY 3.0
The fig buttercup, Ficaria verna is an invasive perennial plant that grows fast in dense mats and up to 8 inches tall and has yellow flowers. The flowers have 7-12 petals with smooth-edged leaves. All parts of the plant are poisonous but the flowers and stems of young plants can be eaten only after they have been exposed to heat (through blanching/boiling). Once the fruits on the plant are mature all parts of the plant are toxic and should be avoided completely!
Because fig buttercup emerges well in advance of the native spring-time species, it has a developmental advantage which allows it to establish and overtake areas rapidly. This is an ecological threat because some of the native plants that are being displaced are crucial nectar and pollen providers for pollinating insects. Studies have shown Ficaria verna to have allelopathic (growth-inhibiting) effects on plants from the Asteraceae and Laminaceae families. Even though the allelopathic effects aren’t very strong they still have an impact and allow the fig buttercup to have another advantage over some native plants. Also, the fact that this plant can be found in large amounts and is toxic, it is a threat to several animals.
Like most flowering plants, the flowers are hermaphroditic and are pollinated by bees, flies and beetles. The fig buttercup is a spring perennial plant that spends much of the year (summer through early winter) underground as thickened, fingerlike tubers or underground stems. After flowering, the above-ground portions begin to die back and the plants are mostly gone by June. Ficaria verna spreads primarily by abundant tubers and bulblets, each of which can grow into a new plant once separated from the parent plant. The prolific tubers may be unearthed and scattered by the digging activities of some animals, including humans trying to pull weeds. The tubers also can spread by rain or even flooding events.
Ficaria verna was introduced to the United States as an ornamental plant for its showy flowers. By 1867, it was collected in Philadelphia, Pennsylvania. By 2008, the plant spread over to Fort Worth, Texas and is now found in 19 states. It is still available commercially in the U.S. along with many colorful varieties. All varieties should be assumed to be potentially invasive.
Eurasia, Northern Africa and Siberia
U.S. Habitat: Woodlands, Meadows and areas with some shade. Tolerant of several soil types as long as there is moisture; but it is not tolerant of acidic soils.
U.S. Present: CT, DE, IL, IN, KY, MA, MO, NH, NJ, OH, OR, PA, RI, TN, TX, VA, WA, WI, WV
Fig buttercup may be confused with marsh marigold (Caltha palustris), a native plant found in wetland habitats in the eastern United States. Marsh marigold has rounded or kidney-shaped leaves and flowers on stalks that are 8 in or more in height and consist of 5-9 deep yellow petals. Marsh marigold does not produce tubers or bulblets, nor does it form a continuous carpet of growth. The fig buttercup also resembles celandine (Chelidonium majus) and celandine poppy (Stylophorum diphyllum), both of which belong to the poppy family and but they can be distinguished from the invasive buttercup by having flowers with four petals.
Care should be taken to correctly identify fig buttercup before undertaking any control efforts to avoid removing native look-alike plants. Since this plant has a short life cycle, the window of opportunity for controlling fig buttercup is very short but it can be accomplished with persistence over time. Manual methods are possible for some (small) infestations, the use of systemic herbicide is more effective because it kills the entire plant including the roots and minimizes soil disturbance.
For small infestations, fig buttercup may be pulled up by hand or dug up. However, it is very important to remove all bulblets and tubers. Due to the abundant tiny bulblets and tubers, all material must be bagged up, removed from the site and disposed properly in a landfill or incinerator.
Axtell, A. E., DiTommaso, A., & Post, A. R. 2010. Lesser celandine (Ranunculus ficaria): A threat to woodland habitats in the northern United States and southern Canada. Invasive Plant Science and Management, 3(2), 190-196.
Cipollini, K. A., & Schradin, K. D. 2011. Guilty in the court of public opinion: Testing presumptive impacts and allelopathic potential of Ranunculus ficaria. The American Midland Naturalist, 166(1):63-74.
Sohrabi Kertabad, S., Rashed Mohassel, M. H., Nasiri Mahalati, M., & Gherekhloo, J. 2013. Some biological aspects of the weed Lesser celandine (Ranunculus ficaria). Planta Daninha, 31(3):577-585.
Woodward, Susan L., and Joyce Ann. Quinn. 2011. Fig buttercup. Encyclopedia of Invasive Species: From Africanized Honey Bees to Zebra Mussels. Santa Barbara, CA: Greenwood. 366-68. Print.