The highly toxic marbled death cap mushroom has been identified growing in WA, where it is believed to have been present, but unidentified, for decades. The mushroom was first collected by long time enthusiast and author Katrina Syme who first noticed the species on her property over thirty years ago, but it had remained unidentified until now.
Health authorities of WA have issued a warning for the South West and Great Southern regions. So far the marbled death cap has been collected only within the Denmark area, but Curtin Adjunct Associate Professor Elaine Davison, who finally identified the species, has advised that at present there are too few documented cases to be sure of where exactly the deadly mushroom may be found.
The marbled death cap, or Amanita marmorata, is a large mushroom which usually has a marbled white-brown cap, but can also appear mostly white, mostly brown or grey. Identifying mushrooms can be a challenge, however, since according to Davison, “Although amanitas are large and conspicuous, there are many undescribed species, especially in WA.”
Davison examined the appearance, microscopic characteristics and DNA of the fungus to make her identification. The DNA work was done by Danielle Giustiniano from Curtin University, with funding from the Australian Biological Resources Study. She said that most marbled death caps found in WA were more white or creamy in colour than those found in eastern states.
Katrina Syme, who has spent years documenting fungi, advised that it is very unlikely the marbled death cap will be found again until March or April next year, depending on rainfall in the region.
Cases of poisoning from a marbled death cap have a fatality rate of around 50 per cent and can cause death within 48 hours. The first symptoms noticed are usually nausea, abdominal pain and diarrhoea. Dr Andrew Robertson, deputy chief health officer for the Western Australian Department of Health, advises that anyone experiencing such symptoms after eating mushrooms should seek medical advice immediately.