Poisonous Plants: Buttercups

Hold a buttercup flower under your chin. If your chin glows yellow, you love butter. That is according to a classic childhood game anyway. Recent research explored the cellular structure of buttercup petals and revealed the anatomical reason behind their yellow glow. Apart from helping to warm the flower’s sex organs, this glow is thought to draw in pollinating insects to ensure proper pollination.

Now take the fresh green leaves of buttercups, crush them up, and rub them against your skin. On second thought, DON’T DO THAT! This is not a childhood game and should absolutely be avoided…unless, of course, you derive some sort of pleasure from painful blisters.

Buttercups, also commonly known as crowfoots, are in the genus Ranunculus and the family Ranunculaceae. Ranunculus consists of a few hundred species and is a common group of annual and perennial herbaceous plants with alternately arranged, palmately veined leaves that are either entire, lobed, or finely divided. Buttercup flowers are usually yellow (sometimes white) with 5 petals (sometimes 3 or 7) that are either borne singly or in loose clusters. The flowers are complete, having both male and female reproductive structures that are easily identifiable. Flowering usually occurs in the spring.

bulbous buttercup (Ranunculus bulbosus) – photo credit: wikimedia commons

Ranunculus species are found throughout the world. Common habitats include moist woods, meadows, open fields, wetlands and other riparian areas, as well as drier sites like roadsides and neglected, urban lots. Several species are commonly grown as ornamentals, and others are common weeds in natural areas, urban landscapes, and agricultural fields.

All buttercups contain a compound called ranunculin. When the leaves are crushed or bruised, ranunculin breaks down to form an acrid, toxic oil called protoanemonin. Contact with this oil causes dermatitis. Symptoms occur within an hour of contact and include burning and itching along with rashes and blisters. When the leaves are chewed, blisters can form on the lips and face. If swallowed, severe gastrointestinal irritation can follow, accompanied by dizziness, spasms, and paralysis. The toxic oil is also irritating to the eyes.

Ranunculus species vary in their levels of this toxic compound, and individual plants are said to be more toxic in the spring when they are actively growing and flowering. Protoanemonin breaks down further into an innocuous compound called anemonin, so dead and dried out plants are generally safe. Commonly encountered (and particularly toxic) species in North America include tall buttercup (R. acris), cursed buttercup (R. sceleratus), creeping buttercup (R. repens), littleleaf buttercup (R. arbortivus), and sagebrush buttercup (R. glaberrimus). Bulbous buttercup (R. bulbosus) has bulbous roots that are toxic when fresh but are said to be edible after they are well boiled or completely dried.

cursed buttercup (Ranunculus sceleratus)

The toxicity of Ranunculus species seems to be more of an issue for livestock than for humans. Grazing animals tend to avoid it since it tastes so bad. Those that do eat it exhibit responses similar to humans – blistering around the mouth, gastrointestinal issues, etc. In The Book of Field and Roadside, John Eastman writes about Ranunculus acris: “Cattle usually avoid the plant – its acrid juices can blister their mouths – though they can also develop something like an addiction to it, consuming it until it kills them.” Buttercups becoming dominant in pastures and rangelands is often a sign of overgrazing.

Despite – and likely due to – their toxicity, buttercups have a long history of medicinal uses. Civilizations in many parts of the world have used the leaves and roots of the plant to treat numerous ailments including rheumatism, arthritis, cuts, bruises, and even hemorrhoids. A report published in 2011 describes three patients in Turkey that had applied poultices of corn buttercup (R. arvensis) to parts of their body to treat rheumatism. The patients were treated for chemical burns caused by the applications. The report concludes by advising against treatments “whose therapeutic effects have not been proven yet by scientific studies.”

In The North American Guide to Common Poisonous Plants and Mushrooms, buttercups are listed among plant species that are skin and eye irritants, honey poisons, and milk poisons (see Appendices 3, 4, and 5). Other genera in the buttercup family may also contain high levels of protoanemonin, including popular ornamentals like Clematis, Helleborus, Anemone, and Pulsatilla. Thus, the moral of this story: handle these plants with care.

sagebrush buttercup (Ranunculus glaberrimus)

More Poisonous Plant Posts on Awkward Botany:

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Field Trip: Chico Hot Springs and Yellowstone National Park

Thanks to an invitation from my girlfriend Sierra and her family, I spent the first weekend in May exploring Yellowstone National Park by way of Chico Hot Springs in Pray, Montana. The weather was perfect, and there were more plants in bloom than I had expected. During our hikes, my eyes were practically glued to the ground looking for both familiar and unfamiliar plant life. Most of the plants in bloom were short and easily overlooked. Many were non-native. Regardless, the amateur botanist in me was thrilled to be able to spend time with each one, whether I was able to identify it or not. I tried to remind myself to look up as often as I was looking down. Both views were remarkable.

On our first day there, we hiked in the hills above Chico Hot Springs. The trail brought us to a place called Trout Pond. There were lots of little plants to see along the way.

Trout Pond (a.k.a. Chico Pond) near Chico Hot Springs in Pray, Montana

mountain bluebells (Mertensia longifolia)

shooting star (Dodecantheon pulchellum)

western stoneseed (Lithospermum ruderale)

western wallflower (Erysimum capitatum)

The next day we drove into Yellowstone. From the north entrance we headed east towards Lamar Valley. Wildlife viewing was plentiful. Elk, bison, bighorn sheep, pronghorn, black bears, red foxes, and even – if you can believe it – Canada geese.

Sierra looks through the binoculars.

Perhaps she was looking for this red-tailed hawk.

Daniel looks at a tiny plant growing in the rocks.

Still not sure what this tiny plant is…

On our third day there, we headed south to see some geysers. We made it to the Norris Geyser Basin and then decided to head east to see the Grand Canyon of the Yellowstone. This was our geology leg of the tour. But that doesn’t mean we didn’t stop to look at a plant or two along the way.

Nuttall’s violet (Viola nuttallii) near the petrified tree in Yellowstone National Park

Wild strawberry (Fragaria sp.) at Norris Geyser Basin in Yellowstone National Park

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Photos of Lamar Valley, red-tailed hawk, Daniel looking at a tiny plant, mystery plant, and Grand Canyon of the Yellowstone were taken by Sierra Laverty. The rest were taken by Daniel Murphy.

Speaking of Sierra, she is the founder and keeper of Awkward Botany’s Facebook page and Instagram account. Please check them out and like, follow, etc. for Awkward Botany extras.

Vines for Spring

I’m taking a break from writing a regular post this time around. It’s the first week of spring, and there is a lot going on. I hope you are getting outside and enjoying the warmer weather (at least those of you in the northern hemisphere anyway). It was a pretty mild winter in my neck of the woods, but that doesn’t diminish my excitement when I see plants start to flower and leaf out. The gray days of winter are largely behind us, and holing up in my cave of an apartment is suddenly less appealing.

What I have for you this week are some short video clips. I recently joined Vine, a short-form, video-sharing social media site where each post is a six second, looped video. I’m late to the scene as usual, but I’ve been having fun messing around with it. The following videos are some of my first attempts (and lousy ones at that); if I decide to stick with it you can expect better content. If you’re interested in this sort of thing, please join, follow, favorite, share, like, comment, etc. Regardless, I hope you will find time to pry yourself away from a screen and experience nature during this beautiful and singular time of year.

 

 

 

 

Awkward Botany is also on Twitter and Tumblr, so feel free to follow me there too if you would like. Happy Spring!