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 Also known as greater celandine . 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 LD 50 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 phyto cystatin chelidostatin, a cysteine protease inhibitor. Cicuta genus Commonly known as water hemlock , cowbane , wild carrot , snakeweed , poison parsnip , false parsley , children's bane and death-of-man . The root, when freshly pulled out of the ground, is extremely poisonous and contains the toxin cicutoxin , a central nervous system stimulant that induces seizures. When dried, the poisonous effect is reduced. The most common species is C. maculata ; one of the species found in the Western USA, 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 Ingestion of its leaves or a dicoction of its leaves causes hypokalemia ( kaliuresis and cardiac arrhythmias ), metabolic acidosis , hypotension and hypoxia . Clivia miniata Commonly known as Natal lily , bush lily and Kaffir lily . It contains small amounts of lycorine , making it poisonous. Codiaeum variegatum Also known as garden croton or variegated croton . 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 Commonly known as autumn crocus and meadow saffron . The bulbs contain colchicine . Colchicine poisoning has been compared to arsenic poisoning; symptoms typically start 2 to 5 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, sufferers 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, although various treatments do exist. Despite dosing issues concerning its toxicity, colchicine is prescribed in the treatment of gout , familial Mediterranean fever , pericarditis and Behçet's disease . It is also being investigated for its use as an anti-cancer drug. Conium maculatum Commonly known as hemlock , poison hemlock , spotted parsley , spotted cowbane , bad-man's oatmeal , poison snakeweed and beaver poison . All parts of the plant contain the alkaloid coniine which causes stomach pains, vomiting, and progressive paralysis of the central nervous system; can be fatal. Not to be confused with hemlock trees ( 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 subgenus Commonly known as larkspur . 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 Commonly known as lily of the valley . Contains 38 different cardiac glycosides . Coriaria myrtifolia Commonly known as redoul . 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. Cytisus scoparius Commonly known as broom or common broom . 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 genus The berries (either red or yellow) are poisonous, causing burns to mouth and digestive tract, followed by coma; often fatal. Datura genus Several species commonly known as jimson weed , thorn apple , stinkweed , Jamestown weed , angel's trumpets , moonflower , and sacred datura . Containing the tropane alkaloids scopolamine , hyoscyamine , and atropine , all parts of these plants are poisonous, especially the seeds and flowers. Ingestion causes abnormal thirst, hyperthermia , severe delirium and incoherence, visual distortions, bizarre and possibly violent behavior, memory loss, coma, and often 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 Commonly known as wild carrot . It can be dangerously toxic to humans . Daucus carota has been reported to contain acetone , asarone , choline , ethanol , formic acid , HCN, isobutyric acid , limonene , malic acid , maltose , oxalic acid , palmitic acid , pyrrolidine , and quinic acid . When in contact with wet Daucus carota , skin irritation and vesication may occur. Deathcamas Various genera in the family Melanthieae have species whose common names include "deathcamas", including Amianthium , Anticlea , Stenanthium , Toxicoscordion and Zigadenus .