con_ct_CALENDINE_050317

Lesser calendine is an aggressive invader of North American forests and has been found in the southeastern part of Wisconsin in moist forests and along river banks.

The Wisconsin Department of Natural Resources is on the lookout for a new emerging invasive threat to Wisconsin forests called Ranunculus ficaria.

Better known as lesser calendine or fig buttercup, this aggressive invader of North American forests has been found in the southeastern part of Wisconsin in moist forests and along river banks where it forms a dense groundcover that crowds out native ground plants, including tree seedlings.

Lesser calendine emerges in early spring, developes small yellow flowers that rise above its glossy green leaves, and dies back in early summer to lie dormant in underground tubers. During the short growing period, the plant produces bulbils that drop off and are spread by gravity, water, small animals and soil movement. These bulbils develop into new plants.

After the plant dies back, the bare ground can erode, damaging water quality. It is also know to invade flower gardens and lawns.

So far, lesser calendine has been found in limited areas in Dane, Milwaukee, Racine and Walworth counties, and control efforts are underway. The DNR wants to know about any other colonies and has a report process available at http://​dnr.wi.gov/​topic/​Invasives/​report.html or send an email to invasive.species@wi.gov. Photos and specimens are helpful.

The plant is classified as a prohibited species under the state’s invasive species law and can not be transferred by purchase or barter, possessed or introduced in the state. 

The DNR offers assistance to help landowners rid their property of this plant. For more information, contact Michael Putnam at 608-266-7596 or michael.putnam@wisconsin.gov, or visit the DNR’s website at http://​dnr.wi.gov/​topic/​invasives/​fact/​LesserCelandine.html.