Sometimes pretty things should be left alone. The buttercup fits that description. It’s very recognizable and grows everywhere. Every spring, young kids pick these attractive yellow flowers with five petals and play with them. I remember holding them under each other’s chins to see if we ‘liked butter.’
I don’t recall any bad experiences personally, but many people have strong skin reactions to buttercup flowers. Sometimes large welts resembling poison ivy blisters can form. In fact, all parts of the plant are poisonous. Simply touching leaves or flowers to sensitive skin can cause dermatitis rather quickly.
Livestock can become ill when grazing fresh foliage and flowers. They usually don’t because the toxins inside the plant taste terrible. For this reason children rarely eat them either. These poisons are called glycosides and are pungent and irritating. I don’t even recommend handling many buttercups with your bare hands. If you have sensitive skin you might want to weed your flowerbeds while wearing gloves if you have to pull many buttercups.
The main culprit, Ranunculin, causes no problems until plant tissue is crushed. When that happens this chemical turns into the bitter yellow oil that causes the problem. Even the smell is a turn-off, so animals seldom get desperate enough to eat this weed. Despite this, tons of buttercups wind up in hay bales every spring.
There is no need for concern though. The drying process renders these toxins harmless and animals can eat the forage without any chance of poisoning. Surprisingly few buttercup toxicity cases are reported each year.
Cooking would destroy these chemicals too, so eating the cooked greens could be safe. I don’t recommend it, since they’d likely still taste bitter and there are too many better things to eat this time of year.
Numerous buttercup species abound and all contain these toxic glycosides. The most prevalent one in eastern North Carolina is the bulbous buttercup (Ranunculus bulbosus.) Native to Europe, it is a common lawn weed and is also found in wet swampy areas. Most buttercup species prefer moist soil. In these places it can be quite attractive if left as a naturalizing ornamental.
Believe it or not, herbalists have been using concoctions of buttercups for centuries to treat various ailments including gout and shingles. Buttercup extracts have antimicrobial properties. I remember reading something about a year ago where scientists were studying bulbous buttercups to see if they could be used to fight MRSA, which causes dangerous antibiotic-resistant staph infections.
For those who want to rid their lawns of this plant, most common broadleaf herbicides are effective. Since buttercups start growing earlier than most lawn grasses they can be killed when the turf is often dormant and less susceptible to injury. Even cool-season grasses like ryegrass and tall fescue are rarely affected by 2,4-D and other common weed killers at labeled rates.
The best way to control buttercups in lawns is simply to use good general cutting, watering and fertilization practices. Keeping a thick healthy unstressed turf discourages most weeds and they never become established.
Ted Manzer teaches agriculture at Northeastern High School.