Gymnopilus junonius is also known as Gymnopilus spectabilis according to some sources (Arora p 411 for example) and I am assuming that equivalence in much of the discussion that follows. It is also known and Big Laughing Gym, since there are reports of the species being hallucinogenic. However, it is more likely that it has been confused with another species of the same genus. Either that, or the chemistry varies a lot (and in fact there are sources which suggest such regional variation in the chemistry). Bettye Rees, an Australian authority on the genus, describes it as a cosmopolitan species (6). She does not equate it with G. spectabilis though, but with G. pampeanus.
This fungus is extremely common in Autumn in my part of the world, forming huge clumps on the base of dying trees and old stumps. It occurs widely across the continent and Rees even suggests that it may be an import due to its presence on pine stumps. I have seen it both on pine stumps and at the base of marri trees. Apart from the reports of hallucinogenic activity, the species is not considered to be poisonous. The dominant feature to anyone who tastes this mushroom is its extreme bitterness. It is seriously unpleasant! Nobody with any sense of taste could possibly consume these, even if desperate for some thrill.
A little bit of experimentation however reveals that the unpleasant bitter taste can be removed by washing with vinegar and probably any other food acid. By contrast, sodium bicarbonate does not remove the bitter taste. This simple experiment reveals that the taste is acid soluble.
Given the knowledge gained from this experiment, I prepared some strips of the mushroom, leached them twice with vinegar and then rinsed with water. The result was something that retained some vinegar taste but was free of the horrible bitterness. I consumed a small portion without ill effect, or hallucinations! So, I put this mushroom forward a possible food.
As with everything, one would need to be very sure of identification before proceeding with this. And any experimentation should be undertaken with caution, but I see some possibilities.
Further notes 28 June 2012
My background in chemistry has caused me to become intrigued with this mushroom. I have done some more research and find an amazing array of conflicting statements, first hand experiences and views on chemistry.
The first thing is that this species does appear to have been responsible for various hallucinogenic experiences and reports of this range from traditional Japanese sources (1), to present day forums that discuss these things. It is said that the mushroom is consumed by people in Oguni in Yamagata prefecture, a mountainous area in Japan without ill effect when the bitter components are removed by boiling in water. (2). The fact that the mushroom is mentioned from traditional Japanese stories, as well as the comment that it is eaten today makes the history of Japanese consumption an interesting topic. It may well have been eaten for a thousand years in Japan. Kusano’s comment “Some people have described intoxication as a result of accidental ingestion of incorrectly cooked mushrooms” is an interesting comment, as it would be hard to eat them if the bitterness was not removed.
There are many sources that say this mushroom contains psilocybin, but many more that refute that.
I cannot find any reports in peer-reviewed journals of isolation of that chemical from this species. It seems much more likely that the presence of that component has been inferred or simply claimed without due diligence (3) and many others.
Correction 23/02/2013: There is a report of psilocybin in this genus, including G. spectabilis, which is another name for this mushroom. The levels are low though.
Other literature sources report and discuss the presence of bis noryangonin and compare these to the components of kava to account for the observed activity. This may be the case, but one might expect the resultant experience to be mild. Rees reports the presence of hispidin and bis-noryangonin in many but not all specimens of the genus in Australia. These are responsible for the yellow colour that has allowed the mushroom to be used to dye fabric.
Yet another explanation of the effects of the mushroom attribute it to the bitter principles, gymnopilins, that are said to have neurotoxic effects. (4). I have a copy of this last paper and the striking thing from my point of view is that the components that they examine are ones that are in the acidic fraction, which is the one we would expect to extract with a solution of sodium bicarbonate. We would not expect these to be extracted by vinegar. It brings me to wonder if they have actually proven that they are examining the bitter principle. There is no mention of taste tests. Their initial extraction with methanol may leave a mushroom devoid of bitterness (it does), but they do not report on the bitterness of subsequent fractions.
So, I caution the reader. The chemistry is not well-defined. The source of any psychotropic effects has three explanations, none of which may be correct. For the moment, I can only report my experience which is that the bitter taste can be removed with vinegar and small portions of the resulting mushroom are edible and non-toxic.
Further tests involving boiling and (acid leaching followed by alkaline leaching) are indicated. This may take years. It is a very interesting exploration though.
References to follow.
Further note 24 July 2012
I found a large specimen and cut off a quarter of the cap and boiled it in about a litre of water for 5 minutes. I then removed the piece and rinsed it with cold water. Tasting revealed that the boiling process had indeed removed the bitter taste from the mushroom. Further tasting revealed that the bitter principle had been transferred to the water broth, which had taken on a rusty orange colour.
Perusal of a forum dedicated consumption of psychotropic mushrooms (5) indicates that people consume the bitter ‘tea’ made from the mushrooms to get intoxicated, so that is further support that the leached mushrooms should not cause any ill effects.
This year I tried slicing one of these mushrooms thinly and boiling it extensively for an hour. I then fried the resulting pieces. The bitter taste was still there. I can’t really much hope of rendering these things into anything taste-worthy.
Even if you can’t eat these, they may be useful in another way. According to the book ‘Mushrooms for color’ by Miriam C. Rice, they can be used with or without mordants to create dyes for fabrics. The fresh mushrooms without mordant give a bright lemon yellow. Dried ones give pale lemon yellow with all mordants except tin which gives mustard. Fresh ones with alum mordant give yellow.
4. Tanaka et al. Neurotoxic oligoisoprenoids of the hallucinogenic mushroom, Gymnopilus spectabilis. Phytochemistry 34