text: amanita phalloides amanita phalloides / / , commonly known as the death cap , is a deadly poisonous basidiomycete fungus , one of many in the genus amanita . widely distributed across europe , a. phalloides forms ectomycorrhizas with various broadleaved trees . in some cases , the death cap has been introduced to new regions with the cultivation of non - native species of oak , chestnut , and pine . the large fruiting bodies ( mushrooms ) appear in summer and autumn ; the caps are generally greenish in colour , with a white stipe and gills . these toxic mushrooms resemble several edible species ( most notably caesar 's mushroom and the straw mushroom ) commonly consumed by humans , increasing the risk of accidental poisoning . amatoxins , the class of toxins found in these mushrooms , are thermostable : they resist changes due to heat and so , unlike many ingested poisons , their toxic effects are not reduced by cooking . some amatoxins will cause irritation and severe pain and even damage to the eyes and skin on contact . they can be absorbed through the skin leading to the same potentially lethal effects as ingestion or inhalation . a. phalloides is one of the most poisonous of all known toadstools . it is estimated that as little as half a mushroom contains enough toxin to kill an adult human . it has been involved in the majority of human deaths from mushroom poisoning , possibly including the deaths of roman emperor claudius in ad 54 and holy roman emperor charles vi in 1740 . it has been the subject of much research , and many of its biologically active agents have been isolated . the principal toxic constituent is α - amanitin , which damages the liver and kidneys , causing hepatic and renal failure which can be fatal . taxonomy and naming the death cap was first described by french botanist sébastien vaillant in 1727 , who gave a succinct phrase name " fungus phalloides , annulatus , virescens , et " , which is still recognizable as the fungus today . though the scientific name phalloides means " phallus - shaped " , it is unclear whether it is named for its resemblance to a literal phallus or the stinkhorn mushrooms phallus . in 1821 , elias magnus fries described it as agaricus phalloides , but included all white amanitas within its description . finally in 1833 , johann heinrich friedrich link settled on the name amanita phalloides , after persoon had named it amanita viridis 30 years earlier . although louis secretan 's use of the name amanita phalloides predates link 's , it has been rejected for nomenclatural purposes because secretan 's works did not use binomial nomenclature consistently ; some taxonomists have , however , disagreed with this opinion . amanita phalloides is the type species of amanita section phalloideae , a group that contains all of the deadly poisonous amanita species thus far identified . most notable of these are the species known as destroying angels , namely amanita virosa and amanita bisporigera , as well as the fool 's mushroom ( a. verna ) . the term " destroying angel " has been applied to a. phalloides at times , but " death cap " is by far the most common vernacular name used in english . other common names also listed include " stinking amanita " and " deadly amanita " . a rarely appearing , all - white form was initially described a. phalloides f. alba by max , though its status has been unclear . it is often found growing amid normally colored death caps . it has been described , in 2004 , as a distinct variety and includes what was termed a. verna var. tarda . the true amanita verna fruits in spring and turns yellow with koh solution , whereas a. phalloides never does . description the death cap has a large and imposing epigeous ( aboveground ) fruiting body ( basidiocarp ) , usually with a pileus ( cap ) from 5 to 15 cm ( 2 to 6 in ) across , initially rounded and hemispherical , but flattening with age . the color of the cap can be pale- , yellowish- , or olive - green , often paler toward the margins and often paler after rain . the cap surface is sticky when wet and easily peeled , a troublesome feature , as that is allegedly a feature of edible fungi . the remains of the partial veil are seen as a , floppy annulus usually about 1 . 0 to 1 . 5 cm ( 0 . 39 to 0 . 59 in ) below the cap . the crowded white lamellae ( gills ) are free . the stipe is white with a scattering of grayish - olive scales and is 8 to 15 cm ( 3 to 6 in ) long and 1 to 2 centimetres ( 3 ⁄ 8 to 3 ⁄ 4 in ) thick , with a swollen , ragged , sac - like white volva ( base ) . as the volva , which may be hidden by leaf litter , is a distinctive and diagnostic feature , it is important to remove some debris to check for it . the smell has been described as initially faint and honey - sweet , but strengthening over time to become overpowering , sickly - sweet and objectionable . young specimens first emerge from the ground resembling a white egg covered by a universal veil , which then breaks , leaving the volva as a remnant . the spore print is white , a common feature of amanita . the transparent spores are globular to egg - shaped , measure 8 – 10 μm ( 0 . 3 – 0 . 4 mil ) long , and stain blue with iodine . the gills , in contrast , stain pallid lilac or pink with concentrated sulfuric acid . distribution and habitat the death cap is native to europe , where it is widespread . it is found from the southern coastal regions of scandinavia in the north , to ireland in the west , east to poland and western russia , and south throughout the balkans , in italy , spain and portugal , and in morocco and algeria in north africa . in west asia it has been reported from forests of northern iran . there are records from further east in asia but these have yet to be confirmed as a. phalloides . it is associated with several tree species and is symbiotic with them . in europe , these include hardwood and , less frequently , conifer species . it appears most commonly under oaks , but also under beeches , chestnuts , horse - chestnuts , birches , , , pines , and spruces . in other areas , a. phalloides may also be associated with these trees or with only some species and not others . in coastal california , for example , a. phalloides is associated with coast live oak , but not with the various coastal pine species , such as monterey pine . in countries where it has been introduced , it has been restricted to those exotic trees with which it would associate in its natural range . there is , however , evidence of a. phalloides associating with hemlock and with genera of the myrtaceae : eucalyptus in tanzania and algeria , and leptospermum and kunzea in new zealand . this suggests the species may have invasive potential . by the end of the 19th century , charles horton peck had reported a. phalloides in north america . in 1918 , samples from the eastern united states were identified as being a distinct though similar species , a. brunnescens , by g. f. atkinson of cornell university . by the 1970s , it had become clear that a. phalloides does occur in the united states , apparently having been introduced from europe alongside chestnuts , with populations on the west and east coasts . although a 2006 historical review concluded the east coast populations were introduced , the origins of the west coast populations remained unclear , due to scant historical records . a 2009 genetic study provided strong evidence for the introduced status of the fungus on the west coast of north america . amanita phalloides has been conveyed to new countries across the southern hemisphere with the importation of hardwoods and conifers . introduced oaks appear to have been the vector to australia and south america ; populations under oaks have been recorded from melbourne and canberra ( where two people died in january 2012 , of four who were poisoned ) and adelaide , as well as uruguay . it has been recorded under other introduced trees in argentina and chile . pine plantations are associated with the fungus in tanzania and south africa , where it is also found under oaks and poplars . toxicity as the common name suggests , the fungus is highly toxic , and is responsible for the majority of fatal mushroom poisonings worldwide . its biochemistry has been researched intensively for decades , and 30 grams ( 1 . 1 ounces ) , or half a cap , of this mushroom is estimated to be enough to kill a human . in 2006 , a family of three in poland was poisoned , resulting in one death and the two survivors requiring liver transplants . some authorities strongly advise against putting suspected death caps in the same basket with fungi collected for the table and to avoid even touching them . furthermore , the toxicity is not reduced by cooking , freezing , or drying . similarity to edible species in general , poisoning incidents are unintentional and result from errors in identification . recent cases highlight the issue of the similarity of a. phalloides to the edible paddy straw mushroom , volvariella volvacea , with and southeast - asian immigrants in australia and the west coast of the united states falling victim . in an episode in oregon , four members of a korean family required liver transplants . of the 9 people poisoned in the canberra region between 1988 and 2011 , three were from laos and two were from china . this misidentification is a leading cause of mushroom poisoning in the united states . novices may mistake juvenile death caps for edible puffballs or mature specimens for other edible amanita species , such as a. lanei , so some authorities recommend avoiding the collecting of amanita species for the table altogether . the white form of a. phalloides may be mistaken for edible species of agaricus , especially the young fruitbodies whose unexpanded caps conceal the telltale white gills ; all mature species of agaricus have dark - colored gills . in europe , other similarly green - capped species collected by mushroom hunters include various green - hued brittlegills of the genus russula and the formerly popular tricholoma equestre , now regarded as hazardous owing to a series of restaurant poisonings in france . , such as russula heterophylla , r. aeruginea , and r. virescens , can be distinguished by their brittle flesh and the lack of both volva and ring . other similar species include a. subjunquillea in eastern asia and a. , which ranges from andean colombia north at least as far as central mexico , both of which are also poisonous . in january 2012 , four people were accidentally poisoned when death caps ( reportedly misidentified as straw fungi , which are popular in chinese and other asian dishes ) were served at a new year 's eve dinner party in canberra , australia . all the victims required hospital treatment and two of them died , with a third requiring a liver transplant . biochemistry the species is now known to contain two main groups of toxins , both ( ring - shaped ) peptides , spread throughout the mushroom tissue : the amatoxins and the phallotoxins . another toxin is , which has shown some hemolytic ( red blood cell – destroying ) activity in vitro . an unrelated compound , , has also been isolated . amatoxins consist of at least eight compounds with a similar structure , that of eight amino - acid rings ; they were isolated in 1941 by heinrich o. wieland and rudolf of the university of munich . of the amatoxins , α - amanitin is the chief component and along with β - amanitin is likely responsible for the toxic effects . their major toxic mechanism is the inhibition of rna polymerase ii , a vital enzyme in the synthesis of messenger rna ( mrna ) , microrna , and small nuclear rna ( snrna ) . without mrna , essential protein synthesis and hence cell metabolism grind to a halt and the cell dies . the liver is the principal organ affected , as it is the organ which is first encountered after absorption in the gastrointestinal tract , though other organs , especially the kidneys , are susceptible . the rna polymerase of amanita phalloides is insensitive to the effects of amatoxins , so the mushroom does not poison itself . the phallotoxins consist of at least seven compounds , all of which have seven similar peptide rings . was isolated in 1937 by feodor , heinrich wieland 's student and son - in - law , and ulrich wieland of the university of munich . though phallotoxins are highly toxic to liver cells , they have since been found to add little to the death cap 's toxicity , as they are not absorbed through the gut . furthermore , phalloidin is also found in the edible ( and sought - after ) ( amanita rubescens ) . another group of minor active peptides are the , which consist of six similar . like the phallotoxins , they do not induce any acute toxicity after ingestion in humans . signs and symptoms death caps have been reported to taste pleasant . this , coupled with the delay in the appearance of symptoms — during which time internal organs are being severely , sometimes irreparably , damaged — makes it particularly dangerous . initially , symptoms are gastrointestinal in nature and include colicky abdominal pain , with watery diarrhea , nausea , and vomiting , which may lead to dehydration if left untreated , and , in severe cases , hypotension , tachycardia , hypoglycemia , and acid – base disturbances . these first symptoms resolve two to three days after the ingestion . a more serious deterioration signifying liver involvement may then occur — jaundice , diarrhea , delirium , seizures , and coma due to fulminant liver failure and attendant hepatic encephalopathy caused by the accumulation of normally liver - removed substance in the blood . kidney failure ( either secondary to severe hepatitis or caused by direct toxic kidney damage ) and coagulopathy may appear during this stage . life - threatening complications include increased intracranial pressure , intracranial bleeding , pancreatic inflammation , acute kidney failure , and cardiac arrest . death generally occurs six to sixteen days after the poisoning . mushroom poisoning is more common in europe than in america . up to the mid - 20th century , the mortality rate was around 60 – 70 % , but this has been greatly reduced with advances in medical care . a review of death cap poisoning throughout europe from 1971 to 1980 found the overall mortality rate to be 22 . 4 % ( 51 . 3 % in children under ten and 16 . 5 % in those older than ten ) . this has fallen further in more recent surveys to around 10 – 15 % . treatment consumption of the death cap is a medical emergency requiring hospitalization . the four main categories of therapy for poisoning are preliminary medical care , supportive measures , specific treatments , and liver transplantation . preliminary care consists of gastric decontamination with either activated carbon or gastric lavage ; due to the delay between ingestion and the first symptoms of poisoning , it is common for patients to arrive for treatment many hours after ingestion , potentially reducing the efficacy of these interventions . supportive measures are directed towards treating the dehydration which results from fluid loss during the gastrointestinal phase of intoxication and correction of metabolic acidosis , hypoglycemia , electrolyte imbalances , and impaired coagulation . no definitive antidote is available , but some specific treatments have been shown to improve survivability . high - dose continuous intravenous penicillin g has been reported to be of benefit , though the exact mechanism is unknown , and trials with cephalosporins show promise . some evidence indicates intravenous silibinin , an extract from the blessed milk thistle ( ) , may be beneficial in reducing the effects of death cap poisoning . a long - term clinical trial of intravenous silibinin began in the us in 2010 . prevents the uptake of amatoxins by liver cells , thereby protecting undamaged liver tissue ; it also stimulates dna - dependent rna polymerases , leading to an increase in rna synthesis . according to one report based on a treatment of 60 patients with silibinin , the patients who have started the drug within 96 hours of ingesting the mushroom and who have still had kidney function intact have all survived . as of february 2014 supporting research hasn ’ t yet been published . has been identified as the human hepatic uptake transporter for amatoxins ; moreover , substrates and inhibitors of that protein — among others rifampicin , penicillin , silibinin , , paclitaxel , ciclosporin and — may be useful for the treatment of human amatoxin poisoning . n - acetylcysteine has shown promise in combination with other therapies . animal studies indicate the amatoxins deplete hepatic glutathione ; n - acetylcysteine serves as a glutathione precursor and may therefore prevent reduced glutathione levels and subsequent liver damage . none of the antidotes used have undergone prospective , randomized clinical trials , and only anecdotal support is available . and n - acetylcysteine appear to be the therapies with the most potential benefit . repeated doses of activated carbon may be helpful by absorbing any toxins returned to the gastrointestinal tract following enterohepatic circulation . other methods of enhancing the elimination of the toxins have been trialed ; techniques such as hemodialysis , hemoperfusion , plasmapheresis , and peritoneal dialysis have occasionally yielded success , but overall do not appear to improve outcome . in patients developing liver failure , a liver transplant is often the only option to prevent death . liver transplants have become a well - established option in amatoxin poisoning . this is a complicated issue , however , as transplants themselves may have significant complications and mortality ; patients require long - term immunosuppression to maintain the transplant . that being the case , the criteria have been reassessed , such as onset of symptoms , prothrombin time ( ptt ) , serum bilirubin , and presence of encephalopathy , for determining at what point a transplant becomes necessary for survival . evidence suggests , although survival rates have improved with modern medical treatment , in patients with moderate to severe poisoning , up to half of those who did recover suffered permanent liver damage . a follow - up study has shown most survivors recover completely without any sequelae if treated within 36 hours of mushroom ingestion . notable victims several historical figures may have died from a. phalloides poisoning ( or other similar , toxic amanita species ) . these were either accidental poisonings or assassination plots . alleged victims of this kind of poisoning include roman emperor claudius , pope clement vii , the russian tsaritsa natalia naryshkina , and holy roman emperor charles vi . r. gordon wasson recounted the details of these deaths , noting the likelihood of amanita poisoning . in the case of clement vii , the illness that led to his death lasted five months , making the case inconsistent with amatoxin poisoning ( p . 110 ) . natalia naryshkina is said to have consumed a large quantity of pickled mushrooms prior to her death . it is unclear whether the mushrooms themselves were poisonous or if she succumbed to food poisoning . charles vi experienced indigestion after eating a dish of sautéed mushrooms . this led to an illness from which he died 10 days later — symptomatology consistent with amatoxin poisoning . his death led to the war of the austrian succession . noted voltaire , " this dish of mushrooms changed the destiny of europe . " the case of claudius ' poisoning is more complex . claudius was known to have been very fond of eating caesar 's mushroom . following his death , many sources have attributed it to his being fed a meal of death caps instead of caesar 's mushrooms . ancient authors , such as tacitus and suetonius , are unanimous about poison having been added to the mushroom dish , rather than the dish having been prepared from poisonous mushrooms . wasson speculated the poison used to kill claudius was derived from death caps , with a fatal dose of an unknown poison ( possibly a variety of nightshade ) being administered later during his illness .