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20 Deadliest Plants on the Planet

Published by nobert soloria bermosa in Science
June 22nd, 2008

Not all plants are beneficial to us.

Plants provide mankind fresh air, foods, and medicines. Plants also beautify our surrounding with their lovely and colorful flowers. These are just some of the many benefits that plants can give us.

Although many plants are beneficial to human beings there are also certain varieties that have been proven to be harmful and fatal to humans. Here’s a list of the deadliest plants in the world. (Photos courtesy of Wikipedia)

  1. Oleander (Nerium Oleander)

    All parts of this attractive bush are toxic especially the leaves and woody stems. Most poisonings have involved ingestions of the leaves. They cause severe digestive upset, heart trouble, and contact dermatitis. It is the deadliest plant in the world. In 2002, there were 847 known human poisonings in the United States related to Oleander and there are innumerable reported suicidal cases of consuming mashed oleander seeds in southern India.

  2. Dumbcane (Dieffenbachia)

    Biting into the leaf causes immediate intense, painful burning in the mouth. This houseplant is one of the most frequently involved in injury to young children. All parts are poisonous, causing intense burning, irritation, and immobility of the tongue, mouth, and throat. Swelling can be severe enough to block breathing leading to death. The Dieffenbachia is considered one of the deadliest plants on earth.

  3. Deadly Nightshade (Atropa Belladonna)

    All parts of this plant contain toxic. The young plants and seeds are especially poisonous, causing nausea, muscle twitches, paralysis; often fatal. Deadly nightshade or belladonna is one of the most toxic plants found in the Western Hemisphere. Children have been poisoned by eating as few as three berries. Ingestion of a leaf of the Belladonna can be fatal to an adult. The root of the plant is generally the most toxic part.

  4. Jimson Weed (Datura Stramonium) 

    This weed is the cause of the first recorded plant poisoning in the United States, in the Jamestown settlement. All parts of Jimson weed which is also known for a variety of names such as datura, thorn apple, stinkweed, and Jamestown weed are poisonous, causing abnormal thirst, vision distortions, delirium, incoherence, coma and often fatal.

  5. Angel’s Trumpet (Brugmansia) 

    All parts of the often fatal plant named Angel’s trumpet or Brugmansia contain the tropane alkaloids scopolamine and atropine.

  6. Monkshood (Aconitum variegatum) 


    All parts of the plant are highly poisonous. Ancient warriors used it to poison their enemies’ water supplies. Used in the past for killing wolves. It causes burning, tingling, and numbness in the mouth, then the intestine, followed by vomiting, death by asphyxiation.

    Aconitum (Aconitum Napellus)

    The poison is concentrated in the unripe seed pods and roots, but all parts are poisonous. It causes digestive upset, nervous excitement. The juice in plant parts is often fatal. Canadian film actor Andre Noble died of aconitine poisoning in 2004, after accidentally ingesting it. Several species of Aconitum have been used as arrow poisons. The Minaro in Ladakh use A. napellus on their arrows to hunt ibex, while the Ainus in Japan used a species of Aconitum to hunt bear. The Chinese also used Aconitum poisons both for hunting, and for warfare.

  7. Yew (Taxus Baccata)

    The seeds are the most poisonous although all parts of the plant, except for the fleshy red bit of the fruit, contain taxane alkaloids. The seeds being especially poisonous are quickly fatal when ingested.

  8. White Snakeroot (Ageratina altissima) 

    All parts are poisonous, causing nausea and vomiting. When consumed by cattle the meat and milk become contaminated. When milk or meat from cattle feeding on White Snakeroot is consumed by humans, the poison is passed onto humans and can result in tremetol poisoning called milk sickness (notably the cause of death of Nancy Hanks, mother of Abraham Lincoln). It is also poisonous to horses, goats, and sheep. Signs of poisoning in animals include depression and lethargy; hind feet placed close together (horses, goats, cattle) or held far apart (sheep), nasal discharge, excessive salivation, arched body posture, and rapid or difficult breathing.

  9. Water Hemlock (Cicuta) 

    The most poisonous part of this plant is the root. The plant is occasionally mistaken for parsnips, due to its clusters of white tuberous roots; this is an often fatal error, as the Cicuta is extremely poisonous. It is considered to be North America’s most toxic plant. Cicuta is fatal when swallowed, causing violent and painful convulsions. Though a number of people have died from water hemlock poisoning over the centuries, livestock have long been the worst affected (hence the name “cowbane”), causing death in as little as 15 minutes.

  10. Moonseed (Manispermum) 

    The fruits and seeds of moonseed are poisonous, causing nausea and vomiting and are often fatal.

  11. Privet (Ligustrum sp.) 

    The leaves and berries of privet are poisonous which causes digestive disturbances, nervous symptoms and can be fatal. Privet is one of several plants which are poisonous to horses. In the some parts of the world where they are not native, some privet species have become invasive weeds, spreading into wilderness areas and displacing native species. This is particularly a problem in North America, where no species of the genus occurs naturally. Privet is a huge problem in New Zealand. It is banned from sale or cultivation in New Zealand due to the effects of its pollen on asthma sufferers. Privet pollen is known to cause asthma and eczema in sufferers.

  12. Poison Ivy (Toxicodendron radicans) 

Liked it
  1. Moses Ingram
    Posted June 22, 2008 at 12:51 pm

    Very informative. Thank you.

  2. quiet voice
    Posted June 22, 2008 at 1:40 pm

    …Hi nobert, your article is very
    educational, I was not aware that
    jasmine was poisonous. As well all
    the other interesting but possibly
    fatal plants. Thank you. Take care.

  3. Unofre Pili
    Posted June 22, 2008 at 3:40 pm

    Good research bro. Informative.

  4. PR Mace
    Posted June 22, 2008 at 4:53 pm

    Good informative article. I have some of these plants in my garden and I had no idea. Thank you.

  5. Judy Sheldon
    Posted June 22, 2008 at 5:03 pm

    Such beautiful flowers, who would guess?

  6. Yeah Right
    Posted June 22, 2008 at 5:44 pm

    The Jimson weed is used by some as a hallucinogenic and is called datura on various drug websites. Check out http://www.erowid.com for information on the effects of Jimson Weed as a drug, its pretty interesting.

  7. Ruby Hawk
    Posted June 22, 2008 at 5:51 pm

    Interesting information, we have plenty of jimpson weed, privit, and yew among others. We always had jimpson weed rowing in and around the pasture but the cows and mules never touched it. When we kids ran thorugh it it would make our legs itch like crazy.

  8. william rodriguez II
    Posted June 22, 2008 at 6:47 pm

    Nice trivia,very informative!

  9. Rachel
    Posted June 22, 2008 at 8:22 pm

    These deadly plants sure look all beautiful plants, not ‘evil’ looking at all.

  10. ione gonzales
    Posted June 22, 2008 at 8:36 pm

    nice work sir! very useful to students like me who are engaged in scientific studies.. :)

  11. carol
    Posted June 22, 2008 at 9:23 pm

    monkshood & aconitum are the same thing: monkshood is the common name for a variety of aconitum (aconitum being the latin name).

  12. medicine
    Posted June 22, 2008 at 9:27 pm

    nearly every one of the plants on this list are the sources for important drugs, many of which fight cancer (Oleander, Yew, Acontium/Monk’s Hood). Toxins, when ingested in extremely small quantities (many millions of times less potent than the natural form) can be incredibly effective at treating some very serious ailments. I’m surprised Fox glove (aka Digitalis) is not on your list (and it is used to treat a myriad of heart conditions).

    oh, and Monk’s Hood is a species of Acontium (wolf’s Bane is another species of Acontium)… just thought you’d like to know that you’ve got a repeat on your list.

    and to “Quiet Voice” whom thought that one of these plants is Jasmine, you’re mistaken (you’re probably confusing it with Oleander which has the latin name Nerium Oleander versus Jasmine which can be any number of sepcies of Jasminum)

  13. Darlene McFarlane
    Posted June 22, 2008 at 9:31 pm

    Most of these plants are so beautiful that you wouldn’t think them to be harmful. I was given a dumbcane plant recently and found out after I brought it home that it is poisonous. I would like to get rid of it but I don’t know what to do with it. We have a couple of acres of land here and I could dispose of it somewhere outside but I am afraid animals might try to eat it. We don’t have young children or pets to worry about but, I have noticed when I touch the leaves that my skin feels like I have been around pink insulation. Any ideas about how to dispose of it would be helpful.

  14. Jacob Russell
    Posted June 22, 2008 at 10:05 pm

    Interesting. Isn’t it curious that so many are surprised that a plant or flower perceived to be beautiful may also be deadly!


  15. nobert soloria bermosa
    Posted June 22, 2008 at 10:34 pm

    thanks to all of you guys,
    thanks carol and medicine- yes they’re the same,there was a slight problem on the numbering-i’ve already submitted a fix though and fox glove is included in the list.

  16. valli
    Posted June 23, 2008 at 12:22 am

    Very informative.

  17. With those crazy red stems...
    Posted June 23, 2008 at 2:29 pm

    The Doll’s Eye looks to me like the loudest advertiser of ‘Leave me alone’.

    They just look alien don’t they?!

    Nice post, thanks for sharing!

  18. tracy sardelli
    Posted June 23, 2008 at 7:43 pm

    excellent article, thank you for sharing.

  19. Emile
    Posted June 24, 2008 at 4:31 am

    Nice post. Could you please for us non-native English speakers supply the Latin names as well? Thanks!

  20. nobert soloria bermosa
    Posted June 24, 2008 at 7:21 am

    thanks again to all of you,

    Emile thank you,no problem with that, I’ll include their Latin names, just check it out later or maybe by tomorrow.

  21. hen26ry
    Posted June 24, 2008 at 8:41 am

    Like Emile I’m missing the botanical names and perhaps the family of the plants. Thank you.

  22. Anna Ski
    Posted June 24, 2008 at 9:38 am

    There is more than I obviously thought. The foxglove was one of my fav’s but now I think not, cause you got to watch out for kids touching or eating them.
    Fantastic article Nobert, thankyou for letting us all know. It’s just that extra bit of information about the plants that matter the most.

  23. Anne Lyken-Garner
    Posted June 24, 2008 at 12:46 pm

    One striking thing about all the plants is that they are all so beautiful.

    A lovely collection of colourful plants. A great article.

  24. .
    Posted June 24, 2008 at 5:22 pm

    * @ Anne Lyken-Garner* There has been foxglove growing around my house for years. I have touched it many times and it does not cause any iritation. I have a 4 year old niece that is at my house often and she loves flowers. She has never tried to eat any of them. Kids are smart if you teach them.

  25. MindIt
    Posted June 25, 2008 at 12:28 am

    “Deadly” information on plants…and nice pics

  26. smg45acp
    Posted June 25, 2008 at 7:20 am

    I have lots of Foxglove around my house. They use the plant for a heart medicine.
    I also have yew and dolls eye.
    Does Castor oil come from the castor oil plant?
    Also the moonflower is a close relative of Jimson weed that is toxic. I have lots of moonflower too, but I was already aware of it being toxic.
    Good list!!

  27. Juliane Elliott
    Posted June 26, 2008 at 1:17 am

    Great article!

  28. lanne
    Posted June 26, 2008 at 7:12 am

    Great list. I have several of these plants and only knew about a few of them being poisonous. I am not surprised though, it seems that the prettier things are, the more deadly they can be. I also found out lately that although we eat rhubarb and it is good for you, if the leaves are boiled, the liquid can kill you.

  29. Me
    Posted June 26, 2008 at 10:37 am

    Very interesting article, but it got a bit old with the poison.

  30. IcyCucky
    Posted June 26, 2008 at 12:42 pm

    Really interesting, and very informative!!!

  31. drez
    Posted June 26, 2008 at 5:35 pm

    wow thanks for putting this together!

  32. Loreta Dorington
    Posted June 26, 2008 at 8:21 pm

    This only shows that what you don’t know can harm you. I hope everybody will get the chance to read this. Thanks for posting.

  33. The Non-Returner
    Posted June 28, 2008 at 2:20 pm

    Great article Norbert! Those Doll’s Eyes plants look really weird. Keep up the good work buddy!

  34. Hein Marais
    Posted June 28, 2008 at 4:03 pm

    Once againg, a great article. Well Done.

  35. alexa gates
    Posted June 28, 2008 at 6:16 pm

    more plants to beaware of! Good stuff to know!

  36. divyaanshu
    Posted June 29, 2008 at 1:43 am

    incredible but true, thanks a lot

  37. Satish Bellavi
    Posted June 29, 2008 at 2:04 am

    It is surprising how little we know about Mother Nature. This article with photos has opened my eyes and am becoming a nature lover.

  38. Linda Galvao
    Posted June 30, 2008 at 10:25 pm

    You did a nice job with your site, especially including the pictures. In my own research I’ve found that white snakeroot is known by two botanical names, Eupatorium rugosum as well as Ageratina altissima. No idea why this is. On my site, Elders First – Improving Quality of Life for Folks with Alzheimer’s and All Elders, I have a section on creating gardens for nursing homes, specifically for folks with Alzheimer’s. Obviously it’s important to choose plants carefully so no one accidentally eats something toxic. Just thought you’d like to know that I put a link to this site on my LINKS page and credited you. I’m adding more toxic plant lists as well as “safe” plant lists, so consider linking back. The address is http://eldersfirst.squarespace.com/blog/. Thanks!

  39. Lucy Lockett
    Posted June 30, 2008 at 11:34 pm

    There is a up and downside to all things! Great article!

  40. Bruce
    Posted July 1, 2008 at 2:30 am

    I’m glad most of these are fairly easy to identify as inedible, but the moonseed fruit looks a lot like currants in the picture. I guess the only way to tell is to squeeze one, since the seeds are different.

  41. Bluesrains
    Posted July 1, 2008 at 9:33 pm

    Thanks for this, its good to know. By the way, youve listed 21 plants, not 20, you forgot to number the plant,

  42. Gerald Stanley
    Posted July 3, 2008 at 3:06 pm

    Awesome facts. great research bra.

  43. Sher
    Posted July 3, 2008 at 7:18 pm

    interesting article you have here….well done

  44. n
    Posted July 4, 2008 at 1:14 am

    I printing this pages, and after work I will go around my house searching and destroying all similar! My wife gona kill me, but ….

  45. Bob Mc Millen
    Posted July 4, 2008 at 10:58 am

    Question? We have 11 acres of these plants—do domestic cats know not to eat them? We have 4 maincoon cats that we recently allow to go outside, but wouldn’t like them to die.

  46. nobert bermosa
    Posted July 4, 2008 at 12:29 pm

    I am no professional regarding that matter, but as far as i know, cats are highly intelligent animals and they know what particular plant they need to eat when they’re sick and haven’t heard any of them getting poisoned by poisonous plants,however, this is just my personal opinion, i would suggest that it would be better to ask an expert regarding the matter. thanks

  47. JC
    Posted July 4, 2008 at 5:12 pm

    I am a nurse and we use belladonna and opium suppositories to control rectal pain and bladder spasms after inserting catheters into the prostate for brachytherapy. It is quite effective. I commend the author of this page and am glad to finally observe what the plant looks like. Thanx

  48. crawdad
    Posted July 4, 2008 at 10:07 pm

    Very informative. It would also be very helpful to include most common locations for all the plants. You have broad information for a few, but some of the worried commenters might feel a bit better to learn that many grow nowhere near them…

  49. louie jerome
    Posted July 5, 2008 at 12:38 am

    Great artiocle. Very informative and some fabulous pictures.

  50. Leo Reyes
    Posted July 5, 2008 at 2:44 am

    Great article and well researched. I have plenty of Dumbcane plants in my backyard. I did not know that it is harmful. I’ll start removing them.

  51. Dorcas
    Posted July 5, 2008 at 4:04 am

    It is very interesting.

  52. Dorcas Clifford
    Posted July 5, 2008 at 4:07 am

    It is worth knowing thanks for that.

  53. R.B. Parsley
    Posted July 5, 2008 at 1:36 pm

    Very interesting article, and informative too! Poisonous plants have long interested me. Its absolutely amazes me just how many of these deadly plants lurk in our back yards. You did a great job researching this article. Keep up the good work Nobert. Its informative articles like this that keep people safe. Excellent writing!!!


    I wasn’t aware Poison Ivy could be deadly. I thought it only made you itch.

  54. Karl Lembke
    Posted July 6, 2008 at 8:58 pm

    Note, by the way, this isn’t a list of the most toxic plants — it’s a list of the deadliest. That is, the plants that result in the most fatalities. Ugly or boring plants are less likely to wind up in gardens, where they’re less likely to be eaten by the unwary.

    So it’s not surprising that the most deadly plants are also beautiful.

  55. Dark
    Posted July 11, 2008 at 12:16 pm

    Thank you very informative. I have seen many of these plants and had no idea of there levles of toxin.

  56. RM
    Posted July 11, 2008 at 12:20 pm

    Well, I don’t know about that because Actaea pachypoda is ugly as hell. Look at it up there. It’s red with big white berries that look like eyeballs. it scared me a bit when I first saw the photo, lol.

  57. suha
    Posted July 13, 2008 at 2:51 am

    i hav the plant #2 @ home!!

  58. friedlinx
    Posted July 16, 2008 at 2:29 am


  59. DillyDally
    Posted July 22, 2008 at 4:39 pm

    Very interesting indeed. Thanks for this fascinating list. Did not know so many of these were so deadly. I have been told that even the smoke of burning oleander does you no good at all, could be true!

  60. ge
    Posted July 29, 2008 at 4:34 am

    Hell, I’ve been hanging around oleanders for years as a child, I never knew they were poisonous.

  61. Nick Howes
    Posted July 30, 2008 at 11:15 am

    Excellent article, fine photos.

  62. nobert soloria bermosa
    Posted July 30, 2008 at 10:07 pm

    thank you all,i appreciate your support very much

  63. Parth
    Posted August 1, 2008 at 6:32 am

    Where’s the RSS feed?

  64. Zoey Raineri
    Posted October 8, 2008 at 12:10 am

    Very informative! I only knew that about 5 of these beauties were so lethal!

  65. Morné
    Posted November 29, 2008 at 2:49 am

    Nice article, but a bit deceptive. The plants listed are obviously only those of commercial,horticultural or legal importance in the west. There are numerous plants that I know of in Africa that are more toxic than at least some of those those mentioned. This includes plants such as Boophane disticha (bushman poison bulb), Acokanthera oppositifolia (bushman’s poison bush), the local equivalent of poison ivy Smodingium argutum (African Poison Ivy) and several others. Many of these plants, as the common names suggest, are/were used traditionally in hunting (i.e. poisoning arrows). Most recorded fatalities from these plants are however associated with traditional medicinal use that went wrong. Often these include multiple fatalities where these plants are used in ritual ceremonies. I’m sure several other not-so-first-world countries and regions can boast or complain about their own share of lethal plants.

  66. Stazee
    Posted January 2, 2009 at 12:28 pm

    Mushrooms are fungi, not plants.
    Extremely unfortunate about your friend. If you can’t definitely identify wild mushrooms as safe to eat, then it’s not worth the risk.

  67. Abrimaal
    Posted April 24, 2009 at 4:29 pm

    “Brugmansia” is a species of Datura too.

  68. Joe
    Posted April 30, 2009 at 6:38 pm

    Sweet very informative.

  69. David Bellamy
    Posted May 19, 2009 at 6:14 pm

    There is plant called a “Triffid”. Very mobile and agressive has sluaghtered humans en masse. In the event you encounter one do not to engage it in conversation, this will antagonise it further. Soiling your trousers and running away screaming like a little girl is the only defence but has yet to prove effective with 100% motatlity rate.

  70. Dr Livingstone
    Posted May 19, 2009 at 6:24 pm

    The Lion plant is an inhabitant of Africa. It hunts in packs thriving on wildebest and antelope. If approached by one shout “BE OFF WITH YOU!!!!” This will extend your like expectancy by one nano second.

  71. Stefani
    Posted October 13, 2009 at 9:34 am

    Hi Mr Robert…

    Thank You, your article was helping me to do my homework..

    God bless you

  72. Posted November 29, 2009 at 6:28 am

    uhhmmm i think the deadliest plant is the arrow tree because if you hold it you can be paralyzed just by holding it

  73. lovella carane
    Posted December 4, 2009 at 6:09 am

    thanks for the tips…

  74. Posted February 21, 2010 at 1:21 pm

    10 Menispermum e not a

  75. Ainne
    Posted March 16, 2010 at 10:36 am

    nice work sir plz carry on

  76. Posted April 27, 2010 at 9:29 pm

    If # 2 plant is ” Deadliest ” so we can relax with the rest of :) )

    The cells of the Dieffenbachia plant contain needle-shaped calcium oxalate crystals called raphides. If a leaf is chewed, these crystals can cause a temporary burning sensation and erythema. In rare cases, edema of tissues exposed to the plant have been reported. Mastication and ingestion generally result in only mild symptoms.[2] With both children and pets, contact with dieffenbachia (typically from chewing) can cause a host of unpleasant symptoms, including oral irritation, excessive drooling, and localized swelling.[3] However, these effects are rarely life-threatening. In most cases, symptoms are mild, and can be successfully treated with analgesic agents,[4] antihistamines,[5] or medical charcoal.[6] Gastric evacuation or lavage is “seldom”[6] indicated.[4] Jennifer S. Boyle, MD, PharmD, and Christopher P Holstege, MD, note that, “In a large retrospective study of 188 patients with plant oxalate exposure, all cases were determined to be minor and all resolved with minor or no treatment.” [4] They also note that, “In patients with exposure to toxic plants, 70% are children younger than 5 years.”[4]

  77. Posted May 28, 2010 at 10:50 pm

    this doesn’t say anything about the most deadliest plant in the world what other websistes are there can you please contact me on aroob.khan@hotmail.com thankyou

  78. Posted June 7, 2010 at 5:21 am

    Thanks for the wonderful information!!
    People and govt organisations are not able to foresee the lurking danger that the various weeds are posing.
    Not only some weeds are dangerous but many weeds cause erosion, and even displace many valuable plants and crops by competing with them for water, nutrients and sunlight.
    These are the main reasons for the disappearance of water bodies throughout the world!!!!
    Thank you once again.

  79. Schuster
    Posted November 8, 2010 at 10:04 pm

    I thought there were supposed to be 20… lol.

  80. Sarah Dubby
    Posted March 24, 2011 at 2:34 pm

    I love this page.

  81. K
    Posted April 28, 2011 at 2:23 pm

    Is this a joke? Where are the rest of them?

  82. Joe
    Posted May 24, 2011 at 7:20 pm

    This is scary. I had no idea these things were poison. I used to play with the Jimson weeds when I was a kid and I have seen a few of the other as well.

  83. Posted May 28, 2011 at 11:36 pm

    Hey Dude where’s the rest of the 8? your page is incomplete! (-_-).
    I’m on a cliff hanger. It was really Interesting. awwwww…. (disappointed)

  84. 100100101
    Posted August 18, 2011 at 7:37 pm

    You forgot to do the caster bean plant as 1, # 1. in fact. Just a bit of it (a grain of sand size) can kill a 160 pound adult. This only applies to the ricin it has, which is 6000 times more poisonous than cyanide. This is probably the deadliest plant of all time (if you breathe in the ricin). It’s common in warm weather areas. This isn’t a “It CAN be fatal”, no, it IS fatal and will kill you if you’re near it without some sort of protection (IF the seeds weren’t taken out already and IF the weather is just right that the ricin can come out and kill you). You don’t wanna mess with this plant because it’s 12,000 more poisonous than rattlesnake venom. This one is like a suicide pill itself. If you tried to, you could, but I’m NOT (you can’t blame me now) suggesting that you use it in this method, I’m just saying that it’s possible. It doesn’t cause any other symptoms other than death (if you got a grain or so). This isn’t a complete page, or an accurate one at that. If this can be updated, that would be nice.

  85. felix
    Posted October 10, 2011 at 8:24 am

    no discription on the poison ivy part..

  86. Posted October 17, 2011 at 2:49 pm

    These are some strange plants. But awesome.

  87. William kluge
    Posted October 18, 2011 at 2:43 pm

    Frrgjgttggrfgrgfdgd I am mad

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