How Toxic are Euphorbias, Really?By Geoff Stein (palmbob)
June 8, 2011
Euphorbiaceae is one of the largest of the plant families and includes many thousands of plants found all over the world. Of these, a small fraction have found their way into cultivation, partly thanks to the amazing variety and ornamental appeal of many of its members. Some of these are among the most unusual, weird, beautiful and easy-to-grow plants in my garden.
Euphorbias typically produce a white, milky sap, called latex, that is relatively irritating to us humans. It is, however, quite useful to the plants themselves. One of the reasons these plants are so easy to grow is these saps have some degree of antifungal and antibacterial activity, which probably keeps them from getting infected easily in cases of injury. And the saps act as excellent wound sealants. Cuttings of these plants often self seal with this latex which I find useful- saves on antifungal powders, and these plants can often be rerooted right away thanks to their latex healing the cut site almost immediately. And of course the latex presumably repels would-be predators that are looking for a plant meal, from insects to large vegetarian mammals. So from the plant's point of view, this sap is a good thing.
Two species of Euphorbia in my yard, cut to show the oozing latex sap that flows through this plant like blood
Acalypha reptans, Miniature Firetail (photo htop) on left (or top) is a Euphorbia relative. Many Acalyphas have toxic, white latex saps; This Croton on the right (or bottom) is another member of the Euphorbiaceae and though not always sappy, it is also toxic (not highly).
These two Jatropha species are among some of the more common Jatrophas grown in cultivation. Left is Jatropha gossypifolia and right is Jatropha podagrica (sometimes called a miniature bottle tree). Both have toxic saps containing phorbol esters and are members of the family Euphorbiaceae
Unlike most other Euphorbiaceaes, Jatrophas tend to have clearish saps (Jatropha malaphensis on the left); The Synadenium grantii on the right is now considered to be in the genus Euphorbia (Euphorbia compacta) and its common name is Dead Man's Tree. It has very irritating white latex saps and is quick to ooze them with minimal provocation. This is a great plant for my garden, but it is one a am somewhat careful about handling so I get the minimum skin and clothing exposure to the saps.
These two Monadeniums (also recently swallowed up into the genus Euphorbia) share the toxic white latex within. Euphorbia kimberlyana on left and Euphorbia reflexa on the right.
Manihot grahmii is one of my favorite trees. It is in the Euphorbia family as well, but does not have such toxic sap, though it is a moderately toxic plant. It is commonly called a Tapioca Tree, I assume because somehow non-toxic tapioca is made from part of it somehow (probably not this same species)
Maybe I'm crazy to think about collecting and planting Euphorbias, particularly in a garden which sees its share of visitors, not to mention one frequented by my own pets. When compared to a REALLY toxic plant like Nerium oleander, a truly deadly toxic plant that is as ubiquitous as Euphorbias are, and planted without discretion all over my state, frequently in public places, Euphorbias simply pale in comparison. Oleander is not only deadly toxic if ingested, but well known as an irritant if handled (sometimes with worse consequences than one may experience with Euphorbia contact), and even burning this plant can create a deadly toxic and extremely irritating smoke. THIS is a plant that should dominate toxic plant lists. Another baddy is Ricinis communis (Castor Bean) page, a truly deadly toxic plant, also commonly grown as an exotic (and a common weed in my area). Conium maculatum (Poison Hemlock) is another one that makes Euphorbias seem like candy. Still, the focus is often on Euphorbias (particularly the hapless Poinsettia)... what about Plumeria? Ever cut a Plumeria and had the sap drip into your eye... or get it on your skin? It is basically similar to Euphorbia sap, only most seem to know that Euphorbias have noxious sap. Not so with Plumerias. Caution. It can blind you, it is toxic to chew on and the sap can burn your skin.
Oleander is one of the deadiest plants on this planet, far and away more dangerous than any Euphorbia species I argue. One leaf of this can kill a child if eaten. Nasty stuff. Yet planted everywhere.
Here is just one of hundreds of street plantings of Oleander in the Los Angeles area. I estimate there is enough Oleander growing in Southern California to kill off the human race ten times over.
Caster Bean weeds in Los Angeles- top ten most toxic plants
Poison hemlock (photo kennedyh) on left- another top 10 toxic plant; Plumeria (right- photo Chris Mankey) toxicity potential seems to be always overlooked.
Anyway, most all the toxic plant lists are extremely long, with little if any objective comments on degrees of toxicity, and Euphorbias are just one of the many of a long list of ‘heavys' in the plant world. Had they not included hundreds of the most fascinating, bizarre and ornamental plants one can grow, I doubt I would really care all that much that this genus gets such a bad rap. But it is one of my favorite genera and I have dozens upon dozens of great plants from all over the world in this genus both in the garden and in pots all over the garden. Yet here I still stand, living and in one piece despite my well known clumsiness and carelessness concerning all plants in my collection. Am I lucky, or are these really the evil plants they are made out to be?
Just two of the hundreds upon hundreds of cool Euphorbias one can collect (left, or top, are grafted crested Euphorbia lacteas, and right, or bottom, is a grafte bizzare species, Euphorbia piscidermis)
The plant on the left is a classic specimen species, aptly named, I suppose, Euphorbia poissonii; right is a lacy, pink and white ornamental garden shrub, Euphorbia xantyi.
Two more of my favorite species to collect and grow, Euphorbia vallida (left) and Euphorbia characias 'Tasmanian Tiger' (right)
Here is a link to a cautionary article already published on this subject: http://www.theamateursdigest.com/epoisons.htm
This article is basically a list of various Euphorbia species (mostly African) and about their well known toxic principles (most about skin and eye irritation) as well as medical uses (purgative, cathartic, etc.) followed by a serious of personal bad experiences with Euphorbias. There is some discussion of severe toxic principles of Tylecodons I did not understand as these are in no way related to Euphorbias or in the Euphorbia family. Though the article is fairly long, it is filled with very few facts and is primarily anecdotal. I wonder if there is such an article about Poison Oak or Poison Ivy. I have personally had experiences with the former and it was far more unpleasant than any Euphorbia reaction I have ever had.
Poison Oak (Toxicodendron diversilobum) has been my own personal bane in the past (photo by Kelli)
I am not going to say that Euphorbias do not have any dangerous principles. They all have the infamous milky, latex sap that is variably irritating when contacted to skin and extremely irritating when gotten on mucous membranes or in the eye. Orally it is also quite irritating and conceivably quite toxic if one should actually ingest enough of it (though why that situation would occur I have no idea). The toxic principles in most Euphorbia saps are phorbol esters. These are compounds that can cause irritation, vomiting and even, over chronic exposure, tumor production (I doubt this last toxic principle is a big concern with most gardeners as few would be careless enough to be repeatedly exposed to these saps after a few bad experiences). Interestingly some phorbol ester derivatives are known for their antitumor activity.
Probably one of the primary concerns most alarmists point out is the lack of public knowledge about Euphorbia sap's irritant qualities. Euphorbias are such a diverse plant group that it is sometimes hard to believe all these different looking plants are related and that all of them, despite their very different appearances, have this toxic sap in them. Additionally there are many hundreds of plants in the family Euphorbiaceae which are not even in this same genus that most of these also share this toxic sap. So it is not always easy to know what plants have toxic sap and which don't. Personally, I don't rub any plant's saps in my eyes or put it in my mouth as I have discovered toxic and irritating saps are certainly not unique to the Euphorbia genus or family (some Agaves have toxic saps, Crassulaceas as well, many Ficus (Fig) species, and as mentioned already, so do Plumerias). I have gotten hundreds of species of Euphorbia sap on my skin and though I have gotten some rashes that burn (worst is when I get some on my lips) none of my personal experiences come close to matching my visit to the hospital after contacting poison oak. But the name Poison Oak perhaps makes the resulting needed medical attention less of an unexpected event.
Euphorbias come in all shapes and sizes -Euphorbia ammak hybrid left, over forty feet tall and Euphorbia anoplia (right) only five inches tall
Some of the most unusual plants, the medusoid Euphorbias (left, or above, Euphorbia esculenta in flower and right,or below, Euphorbia flanaganii, a common garden outlet species, showing sap oozing from a cut 'branch') are among my favorite species to collect.
Some Euphorbias are leafy, shrubby, spineless plants (Euphorbia atropurpurea left or above and Euphorbia lambii right or below)
and some Euphorbias are among the most noxious, spiny plants there are (Euphorbia atrispina left, and Euphorbia pseudocactus 'Zig Zag' I am hold a cutting of on the right... I am far more concerned about the spines on this plant than any sap that might ooze out the cut surface)
Some Euphorbias a spherical, fascinating lumps (Euphorbia gymnocalycioides- left), while others are intensely spiney, filamentous plants (Euphorbia baioensis-right)
There is also some variability in the Euphorbia sap's toxicity from species to species with some only being mildly irritating (such as the case with Poinsettias, always present on everyone's toxic plant lists for some reason) to extremely irritating (such as with Pencil Cacti, Euphorbia tirucali, which are the plants I handle with the most care in this genus). Additionally there is a wide degree of personal sensitivity to these saps with some people getting the mildest rashes while others experience extremely unpleasant sensations and having to seek medical attention for their rashes.
Euphorbia tirucali is my least favorite Euphorbia in terms of sap production- it is an aggressive latex-oozer.
There is no doubt that this is a sap you do NOT want in your eye, but then there are few plants in the garden you do want in your eye and I argue this is not the most dangerous of them. I have gotten some Euphorbia sap in my own eyes after getting sufficient sap on my hands and then rubbing my eyes. It hurt and was quite irritating indeed. But I had a far worse reaction when some sap from a Plumeria I was pruning dripped in my eye- I thought I was going to go blind! It hurt for days and since then I read people can go blind with this sap in their eyes. Getting Plumeria sap in one's eye is a relatively likely scenario as one often has to prune these trees. I find it a good idea to avoid anything plant-like getting in my eyes from now on. I recommend using goggles if one is likely to be in a situation where plant material can get in ones eyes (every try pruning a tree fern? Wear goggles!).
Plumeria are among the most attractive flowers I grow, but beware when cutting the canes, if well watered... sap is similar to Euphorbia sap!
Thousands of plants have thorns which can, and do, do a lot more ocular damage than most Euphorbia saps. Perhaps there should be plant lists with warnings about spiny plants? Since Euphorbias are really rarely eaten, even by pets and children (since they are so noxious tasting) it seems their primary dangers are in being touched inappropriately. But what of plants with other unseen dangers. like hidden spines, sharp edges or falling seed pods? How many species of palms are there with stiff, needle-like spines that I have been stabbed with hundreds of times, just lucky my eyes have not been selected targets (yet). What of the extremely irritating but unseen spines in dried Echium flowers I unhappily discovered when removing them from the yard? Those took weeks to remove and they flew about in the air like so much harmless dust. I think there should there be warnings about these plants, too? It would be interesting to discover how many people have gone blind from being poked in the eye from a plant compared to the number that have gone blind from Euphorbia exposure. I personally know two people who have lost eye sight from spiny plants but so far I have no personal knowledge of blindness from Euphorbia exposure (though I have no doubt those unfortunate people are out there). So yes Euphorbias have somewhat 'dangerous' saps... but then so do dozens of other plants, and so on. Euphorbias really don't compare much to the real dangerous plants in the plant world.
I think these two plants are far more dangerous in my yard than are any Euphorbias. Left is a larger Phoenix with deadly leaf base spines, and even the regular leaflets are sharp enough to easily puncture an eye ball. Right is a beautiful Echium wildprettii (Tower of Jewels)... but when it dies, the miniature spines on the dead flower stalk fill the air like glass dust and are incredibly irritating... you need gloves and goggles to handle this plant!
And really how toxic is this Euphorbia sap after all? How many deaths have been recorded from ingesting Euphorbias or related plants? Who on earth would purposely ingest such an irritating substance? Who, after ingesting it, would be able to keep from vomiting it up? This is the main reason I do not concern myself about growing Euphorbias in my yard around my dogs. Dogs eat everything as very little seems to taste bad to a dog... just ‘different'. Yet no dog would willingly eat enough Euphorbia to get very ill from it or not vomit it up. I could find no mention of canine or feline deaths from eating Euphorbias in my internet searches, despite Euphorbia's extremely common presence in many yards and collections. I could find few fatality discussions about goat or cattle, either, and they eat all sorts of toxic plants that kill them. There are incidences of sheep dying from eating Euphorbias growing among their pasture plants but no comments about how much Euphorbia it took to kill these sheep. An article published by the Washington State University listed 40 toxic plants, most of which have caused human deaths in this country, listed only one Euphorbia and listed it last, stating it was only mildly poisonous (no deaths). And in some parts of the world, some wildlife normally eat Euphorbias as part of their normal diet, apparently with little negative consequences. So really Euphorbias aren't all that dangerous even if eaten, though as you can see, actually getting eaten is a rare experience for most Euphorbias (however, insects seem immune to many Euphorbias and happily chew holes in some of my nicer plants!)
Poinsettias (Euphorbia pulcherrima) are on all the toxic plant lists are really are one of the least toxic of all the 'toxic' plants there are.
Surprisingly the literature is full of remedies made from Euphorbia saps, most involving native peoples who have treated everything under the sun almost with just about every plant concoction they can think of. I guess given time people will try eating everything in their environment hoping to discover some good outcome from their experimentation, including eating Euphorbias. The Chinese, which have tried just about everything, use Euphorbias to treat edema, to get rid of parasites, constipation, lymphadenitis and cirrhosis. It has also been used in holistic medicine to treat diarrhea (interesting that it also helps with constipation?), hair re-growth, asthma, promoting milk let-down, ulcers, venereal diseases (one species I grow in my garden is named for this property) and impotency. Other sites list Euphorbias as a treatment for epilepsy, coughing, cancers, fungal infections, wart removal and rashes (which I find ironic). One species has been found to contain a chemical that is has a powerful anti-inflammatory. And lastly it has been frequently used as an emetic, which does not surprise me one bit, as any time my dogs have tried to nibble on these plants (a rare occurrence), that has been their standard reaction.
Euphorbia antisyphylitica, historically has been used to treat the diseases it got is scientific name for. To me it is just a bizzare ornamental
Euphorbia resnifera is another great looking ornamental, but also now subject of much medicinal research
Though there are thousands of species of Euphorbias, and many more species in related families, all which probably contain these irritating saps, I have only personal experiences with several hundred of these plants. From my point of view, it is their thorns which I am far more careful of as many of them are quite thorny and sharp. Over the years I have had far more injuries due to Euphorbia thorns than from the evil saps within. But I still use some degree of caution when cutting or bumping into certain ‘sappy' species and try not to get the sap on my lips and eyes since I know it can be painful. But here I am today living breathing proof that these plants are not quite as hazardous as some might make them out to be. I wish the same could be said for my outfits, many which have had to be discarded from the permanent damage done to them by getting the latex saps on them. Now THAT would be something I would like to see on a warning label for Euphorbias! Do NOT get this sap on your clothing! It can cause permanent staining that will cause you to spend additional money on replacement outfits.
Cutting Euphorbias always ends up gumming up my tools... this, and clothing damage, are among the cautions I am most concerned about when dealing with my own Euphorbias.
For more perspective on Euphorbias and their dangers, read one of my other articles here:
For some discussion of toxic plants, see this article: