Issue 3, May 13, 2013

Lesser Celandine Becoming a Major Problem in Parts of the State

If you live in northeast Illinois and you frequent wooded areas in the spring, you may very likely be familiar with lesser celandine (Ficaria verna or Ranunculus ficaria) which is also known as fig buttercup and pilewort.  This short, invasive perennial like many others was introduced as an ornamental garden plant.  It is quickly becoming a serious invasive in this state as well as parts of the northeast U.S.  Sale of this plant is only regulated in Massachusetts and Connecticut so Illinois gardeners can purchase this plant for use in their own gardens.  I find it amusing that the cultivar, ‘Brazen Hussy' appears to be aptly named by a breeder with a sense of humor.  I hear that another plant, greater celandine (Chelidonium majus), is grateful to be of no relation to lesser celandine. 

Lesser celandine (Leslie J. Mehrhoff, University of Connecticut,

However, large unwanted populations of this plant are no laughing matter.   Mats of leaves can dominate forest floors blocking light to native plants.  Just a quick survey taken this week of a few land stewards finds that there are known populations of lesser celandine in Cook, DuPage, and Lake counties – more specifically, in these areas:

  • along the flood plain of the Des Plaines river including the town of Riverwoods
  • at the North Branch of the Chicago river
  • near lake Michigan ravines and bluff tops
  • in the forest preserves
  • in the vicinity of the Skokie River.

I'm certain there are many more populations.  This plant is becoming a big problem.

It was first collected in Illinois (at least in the Chicago region) in 1978.  It is often seen in moist areas in lawns or adjacent wooded areas, near streams.  It grows in moist soil of floodplains and seepage areas.  It has appeared in wooded wetlands, both in open sun and in shaded areas.

This spring ephemeral is reportedly in bloom now in Lake County.  The flowers are attractive, up to 3 inches wide, and aid greatly in identification.  They are usually 8-petaled and on stalks.  Lesser celandine flowers profusely and deer don't seem to like to eat the plants.  From a distance, it could be mistaken for marsh marigold (Caltha palustris) however.   

The leaves can be irregular in shape but are generally heart-shaped or kidney-shaped.  Size is variable but they are shiny, succulent, and often dark green.  Once the flowers die back, bulblets (bulbils) are visible above the ground.  It has small tubers that aid with spread and allow it to overwinter.  Leaves and basal rosettes appear again in late winter.

Lesser celandine is difficult to eradicate.  Some have found success with applications of glyphosate (1.5%) very early in the spring.  Wait until temperatures are above 50 degrees F.  Small clumps can be dug by hand, being sure to remove all tubers.  The rosettes however are discrete and can be difficult to locate.  Removing the flowers prior to seed set may help in preventing the spread.  

For more information, check out these factsheets:

Special thanks to Chris Evans of IDNR and Paul Marcum and David Ketzner of INHS for their assistance in collecting information on this species. (Michelle Wiesbrook)

Michelle Wiesbrook

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