Hairy Buttercup: Ranunculus sardous

Friday, March 25, 2016

April is the month of horizon-to-horizon yellow in fields and roadsides throughout our region.  Yellow catches the eye during a drive past City Park on Robert E. Lee Boulevard, and an otherwise boring trip (ahem, for the non-naturalist, that is) to Shreveport on I-49 exposes one to vast stretches of the culprit – Hairy Buttercup, Ranunculus sardous.  The same is true for all the birders making their pilgrimages to Grand Isle and other sites “down da bayou.”

In spite of being one of our most abundant spring flowers, Hairy Buttercup is an introduced species that is native to Europe.  It is very showy in New Zealand pastures, as an example.

Just for fun, its Finnish name is “Etelänleinikki” and its Dutch name is “Behaarde boterbloem.”   These make even Ranunculus sardous seem easy – unless you are Finnish or Dutch.

It is amazing how a non-native species can spread so widely and with such high densities.
The species derives its common name from its pubescent (hairy) stems and leaves.  The leaves are palmate, as are other local species of the genus.  The flowers are a beautiful yellow with five petals.  They are very showy and nice to see along roadsides.

Louisiana has about 10 species of Rananuculus, but all the fields I’ve investigated were primarily R. sardous.  This observation has been verified by the well know botanists Dr. Charles Allen and Chris Reid.

As in other species of this genus, buttercups are toxic when eaten.  They contain ranunculin, which when the plant is wounded or chewed releases the toxin protoanemonin.  This toxin causes nausea, burning of the mucus membranes when ingested, and when it comes in contact with the skin may cause itching, rashes, blister and other such effects. 

Do not confuse real buttercups with the pink to white Mexican Evening Primroses, or Pinkladies, Oenothera speciosa, that some call “buttercups.”  They are distinct and unrelated, but have been called buttercups for generations.  We used to ask kids to smell evening primrose “buttercups,” then jam them into their noses that were left covered with yellow pollen.  This is our most prevalent buttercup memory!
 

 

The spring fields are yellow near Golden Meadow, La., like this one taken April 11, 2014.  Photo by Bob Thomas.

Hairy Buttercups, Ranunculus sardous, are showy and wonderful spring flowers.  Photo by Bob Thomas.

 

A close view of Hairy Buttercup flowers reveals their nice texture and form.  Photo by Bob Thomas. 

Be sure to visit the corner of Marconi Drive and Robert E. Lee Boulevard in New Orleans. Photo by Bob Thomas.

 

This is a typical spring roadside view taken near Sunset, La., along I-49, on April 6, 2014. Photo by Bob Thomas.

Hairy Buttercups (yellow) and Pinkladies (pink) grow together in City Park in New Orleans.  Some folks walked up and said, "Look at the pink buttercups."  Ah, the perfect teachable moment! Photo by Bob Thomas.