| Scientific name | Common name(s) | Family | Description | Picture |
| Abrus precatorius | jequirity, crab's eye, rosary pea, John Crow bead, precatory bean, Indian licorice, akar saga, giddee giddee, jumbie bead, ruti, weather plant | Fabaceae | The attractive seeds (usually about the size of a ladybug, glossy red with one black dot) contain abrin, an extremely toxic ribosome-inactivating protein related to ricin.[citation needed] Symptoms of poisoning include nausea, vomiting, convulsions, liver failure, and death, usually after several days. Ingesting a single seed can kill an adult human.[citation needed] The seeds have been used as beads in jewelry, which is dangerous; inhaled dust is toxic and pinpricks can be fatal.[citation needed] The seeds are unfortunately attractive to children. | |
| Acokanthera spp. | poison arrow tree | Apocynaceae | All five species in this genus exude a sap containing extremely toxic cardiac glycosides including ouabain, which inhibits the sodium–potassium pump N+/K+-ATPase, a membrane transport protein important for regulating electrolyte balance and conducting action potentials in many animal cells. | |
| Aconitum spp. | aconite, wolfsbane, monkshood | Ranunculaceae | All parts are poisonous, containing an alkaloid called aconitine, which disables nerves, lowers blood pressure, and can stop the heart. Even casual skin contact should be avoided. Symptoms include numbness, tingling, and cardiac irregularity. It has been used as a poison for bullets (by German forces during World War II), as a bait and arrow poison (ancient Greece), and to poison water supplies (reports from ancient Asia).[citation needed] If ingested, it usually causes burning, tingling, and numbness in the mouth, followed by vomiting and nervous excitement. It is usually a quick-acting poison and has been used in the past for killing wolves (hence one of the common names). | |
| Actaea pachypoda | doll's eyes, white baneberry | Ranunculaceae | All parts are poisonous, especially the berries, the consumption of which has a sedative effect on cardiac muscle tissue and can cause cardiac arrest.[citation needed] | |
| Adenium obesum | sabi star, kudu, desert-rose | Apocynaceae | The plant exudes a highly toxic sap which is used by the Meridian High and Hadza in Tanzania to coat arrow-tips for hunting.[citation needed] | |
| Adonis vernalis | pheasant's eye, false hellebore | Ranunculaceae | The plant is poisonous, containing cardiostimulant compounds such as adonidin and aconitic acid. | |
| Aesculus hippocastanum | horse-chestnut, buckeye, conker tree | Sapindaceae | All parts of the raw plant are poisonous due to saponins and glycosides such as aesculin, causing nausea, muscle twitches, and sometimes paralysis. | |
| Agave spp. | century plant, maguey | Asparagaceae | The juice of several species causes acute contact dermatitis, with blistering lasting several weeks and recurring itching for several years thereafter.[citation needed] | |
| Ageratina altissima | white snakeroot, white sanicle, richweed | Asteraceae | All parts contain a toxic oil known as tremetol, which is poisonous to cattle, horses, goats, sheep, and humans. Symptoms of ingestion include nausea and vomiting and it is often fatal. When the milk or meat of an animal that has eaten white snakeroot is consumed in sufficient quantities by humans, tremetol poisoning, also called milk sickness, may result. | |
| Agrostemma githago | corn cockle | Caryophyllaceae | Contains the saponins githagin and agrostemmic acid. All parts of the plant are reported to be poisonous and may produce chronic or acute, potentially fatal poisoning, although it has been used in folk medicine to treat a range of ills, from parasites to cancer. There are no known recent clinical studies of corn cockle which provide a basis for dosage recommendations; however, doses higher than 3 g (of seeds) are considered toxic. | |
| Anemone nemorosa | wood anemone, windflower, thimbleweed | Ranunculaceae | The plant contains chemicals that are toxic to animals including humans, but it has also been used as a medicine. All parts of the plant contain protoanemonin, which can cause severe skin and gastrointestinal irritation, bitter taste and burning in the mouth and throat, mouth ulcers, nausea, vomiting, diarrhea, and hematemesis. | |
| Anthurium spp. | anthurium, tailflower, flamingo flower | Araceae | Anthurium plants are poisonous due to calcium oxalate crystals. The sap is irritating to the skin and eyes. | |
| Aquilegia spp. | columbine | Ranunculaceae | Seeds and roots contain cardiogenic toxins which cause both severe gastroenteritis and heart palpitations if consumed. The flowers of various species were consumed in moderation by Native Americans as a condiment with other fresh greens, and are reported to be very sweet and safe if consumed in small quantities. Native Americans also used very small amounts of the root as an effective treatment for peptic ulcers. However, medical use of this plant is difficult due to its high toxicity; columbine poisonings are easily fatal. | |
| Areca catechu | betel nut palm, pinyang | Arecaceae | The nut contains arecaidine and arecoline, alkaloids which are related to nicotine and similarly addictive. Chewing it causes a mild high, some stimulation, and much red saliva, which can cause nausea if swallowed. Withdrawal causes headache and sweats. Use is correlated with mouth cancer, and to a lesser extent asthma and heart disease.[citation needed] | |
| Argemone mexicana | Mexican poppy, flowering thistle, cardo, cardosanto | Papaveraceae | A. mexicana seeds contain 22–36% of a pale yellow, non-edible oil called argemone oil or katkar oil, which contains the toxic alkaloids sanguinarine and dihydrosanguinarine. Poisoning by katkar oil causes epidemic dropsy, with symptoms including extreme swelling, particularly of the legs. | |
| Arnica montana | mountain arnica, mountain tobacco, wolf's bane, leopard's bane | Asteraceae | It contains the toxin helenalin, which can be poisonous if large amounts of the plant are eaten or small amounts of concentrated Arnica are used. Consumption of A. montana can produce severe gastroenteritis, internal bleeding of the digestive tract, raised liver enzymes (which can indicate inflammation of the liver), nervousness, accelerated heart rate, muscular weakness, and death if enough is ingested. Contact with the plant can also cause skin irritation. In the Ames test, an extract of A. montana was found to be mutagenic. The plant's toxicity has led to the U.S. FDA officially declaring it to be unsafe. | |
| Arum maculatum | cuckoo-pint, lords and ladies, jack-in-the-pulpit, wake robin, wild arum, devils and angels, cows and bulls, Adam and Eve, bobbins, starch-root | Araceae | All parts of the plant are highly toxic to humans and most animals. The bright red berries contain calcium oxalate raphides and soluble oxalates of saponins (as well as trace amounts of cyanogens and coniine) which can cause skin, mouth, and throat irritation, resulting in swelling, burning pain, breathing difficulties, and stomach upset. A. maculatum is one of the most common causes of accidental plant poisoning based on attendance at hospital emergency departments. However, their acrid taste and the almost immediate tingling sensation in the mouth means that large amounts are rarely consumed and serious harm is unusual. Touching the plant can cause contact dermatitis. Fresh plant material is more toxic than dried plant parts. | |
| Atropa belladonna | deadly nightshade, belladonna, devil's cherry, dwale | Solanaceae | One of the most toxic plants found in the Western Hemisphere, all parts of the plant contain tropane alkaloids – as do those of its equally deadly sister species A. baetica, A. pallidiflora and A. acuminata. The active agents are atropine, hyoscine (scopolamine), and hyoscyamine, which have anticholinergic properties. The symptoms of poisoning include dilated pupils, sensitivity to light, blurred vision, tachycardia, loss of balance, staggering, headache, rash, flushing, dry mouth and throat, slurred speech, urinary retention, constipation, confusion, hallucinations, delirium, and convulsions. The root of the plant is generally the most toxic part, though this can vary from one specimen to another. Ingestion of a single leaf of the plant can be fatal to an adult. Casual contact with the leaves can cause skin pustules. The berries pose the greatest danger to children because they look attractive and have a somewhat sweet taste. The consumption of two to five berries by children and ten to twenty berries by adults can be lethal. In 2009, a case of A. belladonna being mistaken for blueberries, with six berries ingested by an adult woman, was documented to result in severe anticholinergic syndrome. The plant's deadly symptoms are caused by atropine's disruption of the parasympathetic nervous system's ability to regulate involuntary activities such as sweating, breathing, and heart rate. The antidote for atropine poisoning is physostigmine or pilocarpine. A. belladonna is also toxic to many domestic animals, causing narcosis and paralysis. However, cattle and rabbits eat the plant seemingly without any harmful effects. In humans, its anticholinergic properties will cause the disruption of cognitive capacities like memory and learning. | |
| Brugmansia spp. | angel's trumpet | Solanaceae | All parts of all plants in this genus contain the tropane alkaloids scopolamine and atropine, which are extremely toxic; ingestion is often fatal. These plants are closely related to and were once grouped with members of the genus Datura, which contain the same deadly alkaloids. Effects of ingestion may include losing connection with reality and hallucinations. An unfortunate case has been reported in the neuroscience literature about a young man performing self-amputation with pruning shears after intentionally ingesting Brugmansia tea, boiled from just two flowers. | |
| Caladium spp. | angel wings, elephant ear, heart of Jesus | Araceae | All parts of all plants in this genus contain insoluble calcium oxalate crystals, which are toxic. Symptoms of ingestion generally include irritation and burning of the mouth, lips, and throat, nausea and vomiting, abdominal pain, diarrhea, muscle twitching, and sometimes swelling of the mouth or tongue, which can cause breathing to become fatally blocked. In severe cases chronic kidney disease or renal failure can occur. They are poisonous to dogs and cats as well as humans. | |
| Calla palustris | marsh calla, wild calla, water-arum | Araceae | The plant is very poisonous when fresh due to its high oxalic acid content, but the rhizome (like that of Caladium, Colocasia, and Arum) is edible after drying, grinding, leaching, and boiling.[failed verification] | |
| Caltha palustris | marsh-marigold, kingcup | Ranunculaceae | It contains several active substances of which the most important from a toxicological point of view is protoanemonin. Ingesting large quantities of the plant may cause convulsions, burning of the throat, vomiting, bloody diarrhea, dizziness, and fainting. Contact of the skin or mucous membranes with the juices can cause blistering or inflammation, and gastric illness if ingested. Younger parts seem to contain lower toxin concentrations and heating breaks these substances down. Small amounts of Caltha in hay do not cause problems when fed to livestock, but larger quantities can lead to gastric illness. | |
| Cascabela thevetia | yellow oleander | Apocynaceae | All parts of the plant are toxic to most vertebrates as they contain cardiac glycosides. Many cases of intentional and accidental poisoning of humans are known. | |
| Cephalanthus occidentalis | buttonbush | Rubiaceae | It has several historical medicinal uses, but it is also toxic due to the presence of cephalanthin. | |
| Cerbera odollam | suicide tree, Pong Pong tree | Apocynaceae | The seeds contain cerberin, a potent toxin related to digoxin. The poison blocks the calcium ion channels in heart muscle, causing disruption of the heartbeat. This is typically fatal and can result from ingesting a single seed. Cerberin is difficult to detect in autopsies and its taste can be masked with strong spices, such as a curry. It is often used in homicide and suicide in India; Kerala's suicide rate is about three times the Indian average. In 2004, a team led by Yvan Gaillard of the Laboratory of Analytical Toxicology in La Voulte-sur-Rhône, France, documented more than 500 cases of fatal Cerbera poisoning between 1989 and 1999 in Kerala. They said "To the best of our knowledge, no plant in the world is responsible for as many deaths by suicide as the odollam tree." A related species is Cerbera tanghin, the seeds of which are known as tanghin poison nut and have been used as an 'ordeal poison'. | |
| Chelidonium majus | greater celandine | Papaveraceae | The whole plant is toxic in moderate doses as it contains a range of isoquinoline alkaloids, but there are claimed to be therapeutic uses when used at the correct dosage. The main alkaloid present in the herb and root is coptisine, with berberine, chelidonine, sanguinarine, and chelerythrine also present. Sanguinarine is particularly toxic with an LD50 of only 18 mg per kg body weight. The effect of the fresh herb is analgesic, cholagogic, antimicrobial, and oncostatic, with action as a central nervous system sedative. In animal tests, Chelidonium majus is shown to be cytostatic. Early studies showed that the latex causes contact dermatitis and eye irritation. Stains on skin of the fingers are sometimes reported to cause eye irritation after rubbing the eyes or handling contact lenses. The characteristic latex also contains proteolytic enzymes and the phytocystatin chelidostatin, a cysteine protease inhibitor. | |
| Chondrodendron tomentosum | curare | Menispermaceae | It contains highly toxic alkaloids and is one of the sources of the arrow poison curare – specifically 'tube curare', the name of which is derived from the name of the medicinally valuable alkaloid tubocurarine. | |
| Cicuta spp. | water hemlock, cowbane, wild carrot, snakeweed, poison parsnip, false parsley, children's bane, death-of-man | Apiaceae | The root, when freshly pulled out of the ground, is extremely poisonous and contains cicutoxin, a central nervous system stimulant that induces seizures.[citation needed] When dried, the poisonous effect is reduced. The most common species is C. maculata; one of the species found in the Western United States, C. douglasii, often found in pastures and swamps, has especially thick stems and very large and sturdy flowers which are sometimes harvested for flower displays. This is inadvisable as the sap is also toxic. | |
| Cleistanthus collinus | | Phyllanthaceae | Ingestion of its leaves or a dicoction of its leaves causes hypokalemia (kaliuresis and cardiac arrhythmias), metabolic acidosis, hypotension, and hypoxia. | |
| Clivia miniata | Natal lily, bush lily, Kaffir lily | Amaryllidaceae | Like many other amaryllid species, Clivia lilies contain small amounts of lycorine and other toxic alkaloids, making them poisonous to humans as well as domestic animals including dogs and cats, though large quantities must typically be ingested to cause symptoms of poisoning. The bulbs are considered the most poisonous parts. Symptoms of ingestion may include salivation, vomiting, diarrhea, low blood pressure, convulsions, tremors, and cardiac arrhythmia. | |
| Codiaeum variegatum | garden croton, variegated croton | Euphorbiaceae | As with many of the Euphorbiaceae, the sap can cause skin eczema in some people. The bark, roots, latex, and leaves are poisonous. | |
| Colchicum autumnale | autumn crocus, meadow saffron | Colchicaceae | The bulbs contain colchicine, a potent chemical which binds to tubulin in the cell, impairing or inhibiting a wide variety of normal cellular functions including mitosis, endocytosis and exocytosis, and cellular motility. Colchicine poisoning has been compared to arsenic poisoning; symptoms typically start two to five hours after a toxic dose has been ingested but may take up to 24 hours to appear, and include burning in the mouth and throat, fever, vomiting, diarrhea, abdominal pain, and kidney failure. Onset of multiple-system organ failure may occur within 24 to 72 hours. This includes hypovolemic shock due to extreme vascular damage and fluid loss through the GI tract, which may result in death. Additionally, those affected may experience kidney damage resulting in low urine output and bloody urine, low white blood cell counts (persisting for several days), anemia, muscular weakness, and respiratory failure. Recovery may begin within 6 to 8 days. There is no specific antidote for colchicine poisoning, although various treatments do exist. Despite dosing issues concerning its toxicity, colchicine is also a popular medicine at low doses, prescribed in the treatment of gout, familial Mediterranean fever, pericarditis, and Behçet's disease. It is also being investigated for use as an anti-cancer drug. Certain drugs and conditions can interfere with colchicine metabolism and abruptly increase its toxicity, giving colchicine a reputation for dangerous drug interactions. | |
| Conium maculatum | hemlock, poison hemlock, spotted parsley, spotted cowbane, bad-man's oatmeal, poison snakeweed, beaver poison | Apiaceae | All parts of the plant contain γ-coniceine and its derivative coniine, as well as similar alkaloids, which are toxic to all mammals and many other organisms. Ingestion can cause stomach pain, vomiting, and progressive paralysis of the central nervous system; ingestion of more than 100 milligrams of coniine (equal to about six to eight fresh leaves, or even smaller doses of the seeds and roots) can be fatal for adult humans. Coniine works primarily by inhibiting nicotinic acetylcholine receptors in nerve cells, which can cause narcotic-like effects as soon as 30 minutes after ingestion, followed by an ascending neuromuscular dysfunction leading to paralysis of the respiratory muscles and ultimately death by oxygen deprivation. Contrary to a common myth, scientific studies have disproven that humans can be exposed to hemlock alkaloids by ingesting the milk or meat of animals which have eaten the plant. C. maculatum should not be confused with the trees commonly called hemlock (Tsuga spp.), which, while not edible, are not nearly as toxic as the herbaceous plant. An infusion of poison hemlock is said to have killed Socrates in 399 BC. | |
| Consolida spp. | larkspur | Ranunculaceae | Young plants and seeds are poisonous, causing nausea, muscle twitches, and paralysis; often fatal. Other plants in the parent genus Delphinium are also poisonous and commonly called larkspur. | |
| Convallaria majalis | lily of the valley | Asparagaceae | Contains at least 38 different cardiac glycosides, including convallarin, which liberate hydrogen cyanide when metabolized in the body. All parts of the plant, including the bright red berries, are extremely poisonous. Symptoms of ingestion may include abdominal pain, nausea, vomiting, and irregular heartbeat. | |
| Coriaria myrtifolia | redoul | Coriariaceae | A Mediterranean plant containing the toxin coriamyrtin, ingestion of which produces digestive, neurological, and respiratory problems. The poisonous fruits superficially resemble blackberries and may mistakenly be eaten as such. Can be fatal in children.[citation needed] | |
| Cytisus scoparius | broom, common broom | Fabaceae | Contains toxic alkaloids that depress the heart and nervous system. The alkaloid sparteine is a class 1a antiarrhythmic agent, a sodium channel blocker. It is not FDA-approved for human use as an antiarrhythmic agent and it is not included in the Vaughn Williams classification of antiarrhythmic drugs. | |
| Daphne spp. | daphne, garland flower, mezereum, spurge laurel | Thymelaeaceae | All parts of all species in this genus, especially the berries (variously red, yellow, blue, or black), are highly toxic, the primary active principle being the glycoside daphnin; some species also contain mezerein. Ingestion of even just a few berries can produce a burning sensation in the mouth, severe abdominal pain, vomiting, bloody diarrhea, weakness, stupor, and convulsions, followed by coma; it is often fatal. Corrosive lesions of the oral mucosa and upper gastrointestinal tract may also occur, and nephritis has been reported. The sap and berry juice may cause allergic dermatitis in sensitive individuals. | |
| Datura spp. | jimson weed, thorn apple, stinkweed, Jamestown weed, angel's trumpets, moonflower, sacred datura | Solanaceae | Containing the tropane alkaloids scopolamine, hyoscyamine, and atropine, all parts of these plants are poisonous, especially the seeds and flowers. Ingestion may cause abnormal thirst, hyperthermia, severe delirium and incoherence, visual distortions, bizarre and possibly violent behavior, memory loss, coma, and death. It is a significant poison to grazing livestock in North America. Datura has been used as an entheogenic drug by the indigenous peoples of the Americas and others for centuries, though the extreme variability in a given plant's toxicity depending on its age and growing environment make such usage an exceptionally hazardous practice; the difference between a recreational dose and a lethal dose is minuscule, and incorrect dosage often results in death. For this same reason, Datura has also been a popular poison for suicide and murder, particularly in parts of Europe and India. Reports of recreational usage are overwhelmingly negative. The majority of those who describe their use of Datura find their experiences extremely unpleasant and often physically dangerous. | |
| Daucus carota | wild carrot, bird's nest, bishop's lace, Queen Anne's lace | Apiaceae | D. carota contains falcarinol, which is dangerously toxic to humans. It has also been reported to contain acetone, asarone, choline, ethanol, formic acid, hydrogen cyanide, isobutyric acid, limonene, malic acid, maltose, oxalic acid, palmitic acid, pyrrolidine, and quinic acid. When in contact with wet D. carota, skin irritation and vesication may occur. | |
| Deathcamas | Various genera in the family Melanthiaceae have species whose common names include "deathcamas", including Amianthium, Anticlea, Stenanthium, Toxicoscordion, and Zigadenus. | Melanthiaceae | All parts of these plants are toxic, due to the presence of alkaloids. Grazing animals, such as sheep and cattle, may be affected and human fatalities have occurred. | |
| Delphinium spp. | larkspur | Ranunculaceae | Contains the alkaloid delsoline. Young plants and seeds are poisonous, causing nausea, muscle twitches, paralysis, and often death.[citation needed] | |
| Dermatophyllum secundiflorum | mescal bean, Texas mountain laurel | Fabaceae | The beans contain an extremely toxic psychotropic bicyclic alkaloid, cytisine. Which is related to nicotine. The consumption of one bean is enough to kill an adult. | |
| Dicentra cucullaria | bleeding heart, Dutchman's breeches | Papaveraceae | All parts of the plant contain neurotoxic alkaloids such as isoquinoline and cucullarine, which are known to be poisonous to cats, cattle, and humans. Cattle grazing on the leaves or bulblets may suffer from breathing difficulties, staggering, and convulsions, sometimes fatally. The plant may also cause contact dermatitis if touched. | |
| Dichapetalum cymosum | gifblaar | Dichapetalaceae | Well known as a livestock poison in South Africa, this plant contains the metabolic poison fluoroacetic acid.[citation needed] | |
| Dieffenbachia spp. | dumbcane | Araceae | All parts are poisonous; the culprits are needle-shaped crystals of calcium oxalate called raphides, which can cause intense burning, reddening of the skin, irritation, and immobility of the tongue, mouth, and throat if ingested.[citation needed] Swelling can be severe enough to block breathing, leading to death, though this is rare; in most cases, symptoms are mild and can be successfully treated with basic analgesics, antihistamines, or charcoal.[citation needed] | |
| Digitalis purpurea | foxglove | Plantaginaceae | The leaves, seeds, and flowers are poisonous, containing cardiac or other steroid glycosides. These cause irregular heartbeat, general digestive upset, and confusion; can be fatal.[citation needed] | |
| Dioscorea communis | black bryony | Dioscoreaceae | All components of the plant, including the tubers, are poisonous due to saponin content, therefore it is not typically used internally. However, it has been used as a poultice for bruises and inflamed joints. It has been suggested that black bryony be used topically with caution, due to a tendency for the plant to cause painful blisters. Studies have isolated calcium oxalate deposits and histamines in the berry juice and rhizomes, which may contribute to skin irritation and contact dermatitis.[citation needed] | |
| Dryopteridaceae | wood ferns, buckler ferns, male ferns | Dryopteridaceae | The rhizomes of this family are known to contain phloroglucinol derived compounds, previously used to treat nematode infections. Dryopteris filix-mas poisonings consist of vomiting, diarrhea, vertigo, headache, tremor, cold sweats, dyspnea, cyanosis, convulsions, mental disturbances, visual impairment, or blindness which may be temporary or permanent. There is some record of Rumohra adiantiformis (formerly Arachnoides adiantiformis) causing contact dermatitis. | |