Archive for Fungi

Gymnopilus junonius – a possibility?

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.

Lloydia. 1978 Mar-Apr;41(2):140-4.  (just beyond the online numbers).
An example of a report that fails to find psilocybin is:
Stijve and Kuyper (1988)  Absence of psilocybin in species of fungi previously reported to contain psilocybin and related tryptamine derivatives. Persoonia 13:463-465
as well as ref(2)

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.

August 2015

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.

May 2016

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.

April 2022

Apparently these are widely eaten in South America.  I find it hard to imagine but there you go.  Based on studies of the ITS region of specimens from Australia, New Zealand, Ecuador and Argentina, by Thorn et al in 2020 (7)  the mushrooms are the same in all those places.  If I get the chance I would love to taste what they eat in South America.   Perhaps there is scope for an export market!

The paper by Thorn et al. also mentions that this mushroom does not occur in North America but that there are several other species.   This resolves the issue often mentioned in North America about the species being active on one coast and not the other.   They are different species and neither of them is Gymnopilus junonius.

A possible explanation of the whole dilemma is the existence of Gymnopilus orientispectabilis in Japan which may be the original ‘laughing Gym’ and may in fact contain psilocybin like some other members of the genus.

May 2022

Further revelations.   Apparently these are the most widely eaten mushroom in Uruguay where they are known as the Eucalyptus mushroom or hongos de eucalypto.  They are often used in a sandwich known as a Chivito.  This is something of a national dish in Uruguay and there seems to be some variations on the recipe but it is something like a steak sandwich with egg.  Mushrooms appear to be optional but the method of preparation is variously described as ‘boiling several times and discarding until the water is clear’ as well as ‘pickling’.  So essentially it matches the experiments that I described above.  The mushrooms are sold in market stalls for around 80 pesos per kg which equates to around $2.80 AUD.     They are also used another dish called Choripan which is a type of hot dog made with chorizo and which is popular in Argentina.

There are pickling recipes available online.   This blog has quite a detailed recipe and description of the method as well as some comments on how to select the mushrooms and a long list of comments.   No doubt there are some other interesting recipes there.  The writer comments that they are not the greatest of mushrooms and the vinegar can be invasive but never the less they can deserve a place at the table.

Experienced picklers will probably be familiar with the second part of this general approach. It is not something that I am familiar with and the reader can explore the details with Google translate but I summarise it below.

First part: It is suggested that the young specimens should be used as they are less bitter.   They should be sliced, boiled twice in water for 20 minutes, drained and rinsed and then a third time in water containing vinegar and salt, rinsed and drained.

Second part:  Blanch some carrots in boiling salt water.   Slice onions and garlic.   Boil equal parts of oil and vinegar, add the carrots, onion garlic and mushrooms and take off the heat.

The blog post was published in 2011, before my explorations above so it would appear that they knew about these procedures well before I discovered them independently.

References:

1.  Tom Volk’s fungus of the month for  April 2005

Kusano et al.  Chem Pharm Bull 34:3465-3470

3. In-Kyoung Lee et al.  Mycobiology 36(1):55-59 (2008)

4. Tanaka et al.  Neurotoxic oligoisoprenoids of the hallucinogenic mushroom, Gymnopilus spectabilis.  Phytochemistry 34

, 661-664(1993)

5.  Shoomery forum post #3307843

6. http://www.australasianmycology.com/pages/pdf/20/1/29.pdf

7. Paper by Thorn et. al.

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Marasmius oreades – an expensive import?

Marasmius oreades is known the world over as the fairy ring mushroom.  I have not come upon them in the wild, though they do grow in Australia, having probably been imported from Europe.  I came upon them in a market in Perth, where they were being sold for $160 per kilogram, imported from France!  The picture below shows what they look like by the time they have been picked, shipped and packed. Mousseron In France, these are known as Mousserons. Note.  October 2012.  After investigating further during my trip to France, it appears that Marasmius oreades is known as the Faux Mousseron.  Mousseron is applied to Marasmius oreades by English speakers, while the French refer to Calocybe gambosa or St George’s mushroom as mousseron, or mousseron vrai.  This muddies the waters somewhat as it is not easy to distinguish the identity of the dried specimens above.  The way the stems split and their relative thickness would seem to be contrary to what one would expect from M. oreades.  I will pick some in the morning and investigate this further. I will leave the reader to investigate further the identification of these mushrooms.  This investigation should be undertaken with care, as there are lots of mushrooms that come up in fairy rings, and some of them are extremely poisonous. Here is a link describing them in Victoria. (I need to find a new link it seems) Update October 2012 Here is a picture of some of these mushrooms growing in France, in the village of  Correze, which I am visiting to attend the annual mushroom festival.  These are in the lawn of the place where I am staying.   I will take one down to the fete tomorrow to have the identification verified.

Marasmius oreades growing in France

A couple of distinctive features of this mushroom are the dark raised central region of the cap, and the toughness of the stem, which can be twisted back on itself without breaking.

Twisted fairy

While I was in France, I was invited to visit a farm in the Alpes Maritimes, at an elevation of 1000m.  Here I was shown M. oreades growing in classic fairy rings in an open paddock.   The rings could be seen quite clearly by their dark green colour in comparison to the surrounding grass.  The image below shows my host kneeling down to harvest some mushrooms from one of the rings.

Picking M. oreades from fairy ring.

Picking M. oreades from fairy ring.

See also my fellow blogger for further information

.

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Wood ear – an Asian cooking favourite

Wood ear mushrooms, Auricularia cornea, are often seen for sale in Asian food shops.  The grow quite widely on the east coast – I have seen them around the Lismore area, and they grow in the  Cairns area as well as in the Hunter valley, where you can find an excellent description here.

I don’t have an image in my collection, but if someone would be kind enough to donate one, I would be happy to use it and give appropriate credit.

I have not eaten this one, and don’t know how to cook it either, but would be happy to have information on this.   Cultures of these mushrooms are available in Australia, via an enthusiast, on the east coast at least.

Update 29 June 2012

I have had a kind offer of use of images from Kathy.  Here is one reproduced below.

Auricularia cornea by Kathy

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Chlorophyllum-a mixed bag

Chlorophyllum brunneum

brunneum
Chlorophyllum brunneum

A species which is frequently encountered, particularly around chicken coups is Chlorophyllum brunneum, pictured above.  (You may see this same picture in a book, used without permission and mis-labelled)  This is distinguished by the basal bulb which is described as ‘abrupt’, which means that there is usually a definite change in geometry at the top of the bulb and it often has quite a flat top. They often cluster together from a common large basal bulb as shown below.

 It also has a surface that is broken up into scales that have a fibrous appearance.  When cut it turns red.

Personally I find Chlorophyllum brunneum to be a very tasty mushroom with a strong meaty smell and flavour.  But apparently it does not agree with some people so caution is wise.  There is some reason to believe that bad reactions can be avoided by making sure that the mushroom is well-cooked  It is possible that this mushroom contains a toxin similar to Chlorophyllum molybdites but of lower amount or strength. Since this is a protein toxin with a known molecular weight it should be possible to determine this by electorphoresis.

Although this mushroom is similar to Chlorophyllum rachodes, we are advised by mycologist Else Vellinga that that species does not occur in Australia.    Here is a link to Vellinga’s paper.

Below are another couple of images of Chlorophyllum brunneum.  The first shows a young fresh specimen and the other shows a close-up of the gap between the gills and the stem where a green ring can be seen.

This tale of poisoning by my friend Martin is reproduced with his permission

“““““““““““““““““““““““““““““““““““““““““““““““““““““““““““““““““““““““““““““““““““““““““““““““““““““““““““““““““““`

I post and record this experience here so others won’t make the fatal mistake I did but also to potentially kill off some of my mushroom ego if you like

So as some of you may know I escaped the mainland last week on the last flight into tassie to go bushwalking with my wife who is not my wife who I would like to be my wife and step daughter etc both to Bush walk but secretly to hunt down in my opinion what I have heard to be the worlds greatest tasting mushrooms – and later I will post other things about various finds and it was really tongue to ground amazing but the story I am about to share was not so amazing well actually it was kind of amazing – you can see from the above grammar is not my strong point

So I picked some C brunneum (pictured) before the 7 day hike – and they were growing on mass like most mushrooms in Tasmania do – and on day one of the hike I got lost and a 7 hour walking day turning into an 11 hour walking day so when I arrived to camp I got out a bottle of wine and the Brunneys – Now I have eaten these mushrooms on three previous occasions and they are marvellous – so I told the rest of the camp the stories of hunting them down and cooked up a batch on high heat in the pan and surprisingly everyone except one fellow took my word for it and ate them – I was surprised as most people I find not so open to new mushrooms – but my banter must have been right on point cause everyone agreed a great tasting mushroom – and at this point I was the mushroom king

But this is where the story takes a twist

My wife who is not my wife but I would like to be wife offered to cook the next batch as I was tired and dead from walking and getting lost and mentioned something like I will cook these with less oil and low heat to save on gas etc and by this time I was tipsy and ranting about black trumpets and finding the lost porcini of Tasmania etc that I didn’t give it a second thought and a very large plate of mushrooms shortly arrived in front of me warm and a little on the raw side which I devoured very quickly with waving arms and dancing.

Fast forward a few hours later in my sleeping bag and I turn to my wife who you know isn’t my wife and she has ear plugs in and i say I feel sick and she says you always say that after eating mushrooms etc.

I just make it out the door and I am projectile vomiting all over the forest and everybody can hear the mushroom king – and this vomiting goes on and off for the next hour and it’s minus 3 outside and my wife is yelling at me also and nothing is subtle here – maybe no one can hear me I think – after cleaning up and hiding all the spew and evidence I think maybe no one will catch on And I make it back to bed.

After an hour or so there are indescribable sounds coming from my belly – and I should probably wind it up here but I really want to crush a good part of my mushroom ego here so I will continue – I find myself in thermal onesie which happens to be inside out
And I am listening to the sound in my belly going wow that sounds very impressive and then I think I need to get out of here quick
I make it to a tree and can’t find the zip as it not on the outside and what unfolds now is many folds and it’s too late to stop it and it’s coming out my ankles

The rest of the details and screams and tears into the frozen night is not that important here the clean up in frozen river etc

Over the next 6 days I found amazing edible mushrooms but I was now on a ban – my wife who is not my wife who I want to marry who won’t currently marry me has banned me from eating mushrooms and I had lost my title of the mushroom king – but over the next days I would find fields of giant laccaria and 10s of thousands of golden chanterelles and wild enoki and fist sized hedgehogs and I was banned
And no one believed anything I said at the camp – I was reduced to nothing and a laughing stock – but secretly I was happy to have lived through it cause you need some setbacks to clarify where you are headed in life don’t you think ?

The ban was lifted when on the 7th day the chants appeared thank the lord – and I am alive to tell the tale – I remember shouting into the night my kidneys are going to explode get a helicopter here now to Rosie my wife who is not

So what to take from all this –
Peter Donecker will probably be able to tell me what chemical I ingested in the brunneum and the importance of making sure chlorophyllum is well and truly cooked at a high heat etc before sticking them down the throat

The good news is I am alive
And have been eating many mushrooms and have been taken down a fair few pegs
But haven’t eaten Brunneum again
But I will be in Melb on Tuesday so hoping to find some.

Chlorophyllum molybdites

Another member of the genus, Chlorophyllum molybdites (below) has a very similar appearance, but the scales do not have the fibrous nature of C. brunneum.  The gills start out white then gradually turn green. This green colour becomes much more pronounced as the specimens age and eventually the gills become very dark grey-green. It also has a green spore print when mature.

Green_gill
Chlorophyllum molybdites showing green gills

The spores have a green colour that can be seen from a spore print.

Green spore print of Chlorophyllum molybdites

It is sometimes claimed that this mushroom does not stain red, but this picture shows that it does indeed give a red stain when cut in two. Not quite as vivid as Chlorophyllum hortense but undoubtedly red.

Red colour of cut stem

The lower half of the stem on this mushroom has dark shading. This can vary a little in intensity. The annulus has two edges. These features are seen on the next image.

View showing gills and annulus

Sometimes the scales are almost absent as in this specimen from a verge in suburban Perth where it is sometimes particularly prevalent in periods of high temperatures and wet conditions.

It is not a deadly mushroom, but it may make you very sick and is a common cause of mushroom poisoning in North America. The nature of the poison in this mushroom was a mystery for a long time, particularly since it doesn’t affect all people at all times.  It was revealed in 2012 to be a  protein called molybdophyllysin by Yamada et al.  It is heat labile, beginning to break down at 70 degrees, which may explain why some people, including the Cribbs report having eaten C. molybdites without ill effect.

The effect of temperature on the toxin in Chlorophyllum molybdites is shown in this graph from the above mentioned paper which plots activity against temperature for a 10 minute hold time.   It might be anticipated that prolonged boiling might considerably reduce toxicity.  There is similar information on the heat lability of this mushroom in a 1974 paper by Eilers and Nelson where it is referred to by an earlier name, Lepiota morganii.   They report extraction of the toxin with different solvents, water being the most effective.  One of these days I will take this data and try to concoct an equation for the reaction kinetics.  They also mention that the toxin occurs in both young and mature specimens and in all parts of the fruiting body.  This snippet of information eliminates a hypothesis that the toxicity is related to the stage of development of the mushroom.

Molybdophyllysin is a zinc metalloprotease. There are many of this type of enzyme in the biosphere, some toxic and some not. For example, Grifola frondosa, the famed ‘Maitake’ mushroom contains an enzyme of this class. It has found application as a tool for protein analysis as it cleaves proteins in a very specific way. On the other hand the toxin from Clostridium botulinum, the toxin that causes botulism is one of the most potent toxins known. Many studies have been done on the thermal stability of botulinum toxin and it is interesting that the recommended cooking time is a minimum of 5 minutes at 85 degrees centigrade. It would appear that the degradation of molybdophyllysin (MP) may follow very similar kinetics. One difference however is that MP is more susceptible to acidic conditions.

molybdophyllysin temp effect

As a footnote, there is a report of the effects of eating this mushroom in the Medical Journal of Australia, by local academic Lindsay Mollison. I note that his report is in December 2011 and that he speaks of doing an extensive internet search to find out what he had eaten.   Perhaps his experience was just prior to when I made this original post in July 2011.  A shame. The first publication scientific publication describing this mushroom from Perth was written by mycologist Neale Bougher in

Although Chlorophyllum molybdites is considered poisonous in most places, there are reports of it being eaten in various places, particularly in Benin, in Africa.  If you don’t know where that is, I have included a map below.

benin map

Here is a quote from a long treatise on the edible mushrooms of this country.

“In the area where we worked, there is no information on cases of poisoning caused by ukulé malu, nan bisu or bela-dedji. Benin is apparently only occupied by an edible form or with a low toxicity rate. It is also found that Chlorophyllum aff. molybdites is known and appreciated by the Peuhls, an important ethnic group that crosses the entire Sudano-Guinean region of West Africa. Finally, we point out that in Benin, mushrooms, with a few rare exceptions, are always eaten after preparation, that is to say after warm and relatively long heating. If the Chlorophyllum from Benin contained a labile toxin (thermolabile), it would be systematically destroyed by cooking or by blanching. It is clear that further toxicity and taxonomic studies will be needed to clarify and understand the toxicity of Chlorophyllum. For this reason we identify all our collections provisionally as Chlorophyllum aff. molybdites.

from: (PDF) Guide to edible mushrooms in Benin. Available from: https://www.researchgate.net/publication/328043576_Guide_des_champignons_comestibles_du_Benin [accessed Mar 08 2021].

It is possible that the species from Benin is in fact the closely related Chlorophyllum paleotropicum which also features green-grey spores.

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Laetiporus sulphureus – an exciting prospect

In other parts of the world Laetiporus sulphureus is known as chicken of the woods and is  considered a good edible mushroom. I had not heard of any occurence in Australia, but Ray Palmer of north Queensland has reported it growing on Eucalyptus near his home.  You can see Ray’s pictures on his Flickr site, here.

I would emphasise that I have not eaten this mushroom, and I am not aware that Ray or anyone else has either. So it is in the ‘potential’ category for the moment. But an exciting prospect!

Note 26/2/2013.  Since it is reported as edible in the comments below, I have upgraded this to the ‘edible but untried’ category.

If should be noted that the edibility of L. sulphureus depends on the substrate.   On this page, they recommend that you don’t eat it if it is growing on Eucalyptus.

If anyone has any further information on this, I would be most interested to hear about it.

Footnote:

As noted in the comments below, Forthferalz has drawn my attention to some other references to this fungus in Australia.  This picture is provided by blueswami.

I am not sure what angle this was taken at, but in comparison with other pictures, it seems to be upside down.  I think it looks more realistic like this:

There appears to be quite a wide variety of morphologies and colours for this genus.  Even in North America, where it is widely consumed, there appears to be differences between the east and west coast experiences, as well as some confusion about which species is being consumed.

Update  16/04/2016

I have recently had the chance to observe this mushroom first hand in the Dorrigo/Bellingen area of NSW.   It was growing on fallen logs and on the base of a living tree which was also host to Omphalotus nidiformis.  These observations were made in March of a dryish year and I was able to see examples of it over a range of forests.  Here is a picture of one on an exposed lateral root of a rainforest tree along with Omphalotus.

Laetiporus and omphalotus

Laetiporus sp. together with Omphalotus nidiformis

I haven’t shown a picture of the pores, but they were white .  This isn’t the right colour for Laetiporus sulphureus.  It is interesting also that this species appears to be restricted to the warmer regions of the country, while L. sulphureus grows in places like England.

Some light is thrown on this subject by Michael Kuo, the Mushroom Expert.  His comments can be found at this link.

It seems that there are numerous closely related species of Laetiporus in the US.  It is entirely possible that the species here in Australia is yet another one.  The fact that the ones I have observed grow at ground level indicates that they are not L. sulphureus.  To my knowledge it has not been formally named yet. Neither has it’s edibility been established.  Given that there have been numerous cases of people experiencing gastro-intestinal distress from eating various forms of this mushroom in America, it is entirely possible that our local species will cause the same problems.   So there it stands.  At first exciting, but in the end an enigma.

 

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Pluteus petasatus – edible, but not great

For a few years I have noticed some mushrooms coming up after I had burned piles of branches and stumps and so on. At first, I thought these were Volvariellas, but closer inspection showed that they were Pluteus petasatus. They have quite a distinctive cap, grow in clusters and have a characteristic pink spore print.

For some reason, these mushrooms tended to grow at the base of some tall weeds that also grew after the fire. I have no idea what the basis of this association is.

David Arora records this mushroom as being the best of the genus Pluteus, but after frying some up and tasting them, I concluded that they were very similar in taste to Volvariella speciosa (now called Volvopluteus gloiocephalus) and are not something that I would be drawn to eat in particular. Like Volvariella, they would probably go well with some silverbeet or spinach.

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Laccocephalum mylittae – an ancient edible

After there has been a bushfire in the forests around here, and in fact in many parts of Australia, there are a number of fungi that are triggered to send up fruiting bodies. One of these is Laccocephalum mylittae  (formerly Polyporus mylittae), known in early colonial times as Blackfellow’s bread. This is because it was eaten by the Aboriginal people and it has a sclerotium with a texture rather like grains of cereal pressed together. When sliced it is dense like pumpernickel. This fungus may well have been consumed as a food for tens of millenia. It is widespread across the country.

The fungus spends most of its existance feeding on fallen or buried logs. From this woody matter it transports material to a large underground sclerotium which slowly grows in size. It is reported to grow to as large as 600 mm diameter, but the ones I have seen have been about the size of a football. The sclerotium is heavy, with an estimated relative density of 1.1. This growth may go on for 30 years or more, until there is a fire to trigger off the cycle. The sclerotium rapidly sends forth a fruiting body which is apparent at the surface of the ground within a couple of days of the fire. These are commonly seen along side fallen logs. The mushroom is fairly non-descript at first, eventually becoming more defined as it consumes the sclerotium over a period of about a month.

Here is a young mushroom with the sclerotium attached. The mushroom is white, whereas the sclerotium has a dark brown skin covering it.

One can easily imagine that the Aboriginal people would have swept through areas they had burned a couple of days earlier to harvest the scelorotiums, which can be quite numerous. Being dense, they provide a significant food source and they do not appear to decay rapidly. They can be crumbled up and dried out into something resembling a cereal grain. Whether the Aboriginal people did this is probably unknown. The picture below shows the scerotium cut open to reveal the inner texture.

It is entirely possible that this fungus could be cultivated like any other wood rotter. I have a specimen that I will attempt to clone if I have the time and inclination. It might make an interesting addition to our native food cuisine. I would describe the taste as bland, but a friend found it to be quite pleasant. It would lend itself to some creative cooking. Apparently, it has significant nutritional value.

The mature specimen is shown below. It can be seen that the mushroom has grown, while the sclerotium has become depleted.

The spores of this species are shown in the image below.  These measurements were done using the software called Piximetre.   I am still mastering this software, the instructions of which are written in French, but I think this captures the main features.   The average spore size is 9.4*4.3 microns. More detailed statistics are shown.  These spores were stained with Melzer’s so judging by the image they do not appear to be amyloid.  The measurement shown in blue is from my microscope software which was calibrated with an etched slide.  The image is taken at 40X without oil.

Spores of Laccocephalum mylittae

The structure of the pore surface is shown in this image. The spaces on the scale are 1mm.

Pore surface of Laccocephalum mylittae

The pore depth is slightly greater than 2 mm.

Pore depth Laccocephalum mylittae

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A look-alike Psathyrella

This small cluster of mushrooms appeared recently in a garden bed amoungst some horse manure.

These mushrooms have a white cap with a brown colouration in the middle and when we flip them over, we can see that the gill colour is in the right range.

However, if we try to separate the cap from the stem, we find that we can’t, and the stem is furthermore completely hollow and thinner than what we might expect from an Agaricus.  The mushroom pictured is Psathyrella candolleana.  There is another species more commonly seen in forests called P. aspersopora.  Both are of unknown or doubtfull edibility.

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Phlebopus marginatus

Phlebopus marginatus has the largest fruiting body of any mushroom in Australia.  It is a truly spectacular mushroom.  I am including it here as it is recorded as being edible, but the sheer joy of the whole growth event may surpass any pleasure from eating it.

In Western Australia it is known as the Salmon gum bolete, and  Roger Hilton has recorded it as being edible.  The indigenous people did not eat this mushroom however, according to a report by James Drummond in the 1850s.   The pictures below, however, are from Victoria  (thanks lizza)

It grows in rings.  These might be described as circles of giants.

The actual size of an individual mushroom can be up to a metre in diameter.  This picture shows one in comparison with a block splitter that is 800 mm in length.

Whereas in Western Australia this species grows mainly in the wheat-belt which has a relatively low rainfall (300 -600 mm/a), similar mushrooms in the eastern states can grow in quite different locations where it is much wetter (+600 mm/a). Information on the distribution likely to be somewhat influenced by the fact that there are other large un-named boletes that could easily be mistaken for this species.

It is notable that specimens in the eastern states often display a blue colouration in the flesh whereas those from Western Australia do not display this feature. There has been no systematic study of the variation in this genus across the country, but it is notable that there are 5 species listed in the Queensland Mycological Society list of boletes. Given the significant difference in the rainfall patterns between the areas it occurs in Western Australia and on the east coast, it is quite possible that the species in WA is in fact different from those in the east.

My friend Jsun Lau reports finding this species in northern NSW and comments on it’s edibility. The specimens he shows however differ somewhat from those shown above.

It is unclear how it got the name Salmon Gum Bolete, but it is probably because it was thought be in mycorrhizal association with that tree, Eucalyptus salmonophloia which occurs across the range where this mushroom is normally found in Western Australia. This tree does not occur naturally in the east coast however, so the terminology is really not really appropriate to the vast majority of recorded occurrences. It is a pretty tree however and I include a picture of it here just for interest.

Eucalyptus salmonophila

Because of its size, this mushroom has always been an item of curiosity. This image, from the State Library of Western Australia, George Henry Riches collection of glass negatives ; BA2751/137, shows a young Harry Ferries sitting on what can only be one of these mushrooms, probably in the Wyalkatchem area in the central wheatbelt area around 1905.

The genus Phlebopus has a wide distribution usually described as pan-tropical. In this regard the species from Western Australia is very much an outlier. It is consumed in various countries such as China, Thailand and Reunion. Given the poor reports regarding the taste of specimens found in Australia, it seems that the species found in other countries may have a more appealing taste. Studies are somewhat hampered by the fact that the mushroom is often infested with insect larvae and it is not easy to preserve specimens.

Although this mushroom was originally assumed to be mycorrhizal, the situation is much more interesting than that. It has been grown in culture without any host tree but more interesting still is that it has been found to be in a three-way relationship with tree roots and mealy bugs. This is described in a fascinating paper by Fang et al in 2020. The fungus participates in the formation of a gall on the roots of the tree which provides the mealy bug with protection. The galls are lined with the mycelium of the fungus. The mealy bugs have mouth parts that are able to penetrate through the mycelium layer and into the roots from which they draw sustinence. The mealy bugs in turn exude ‘honeydew’ which provides food for the fungus.

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Identifying a field mushroom

Disclaimer  :  These notes are provided as a guide only.  While every attempt has been made to try to assist in the identification, the risk of eating any wild mushroom rests with the individual and I do not accept  any responsibility for consequences  that may arise from the action of anyone eating wild mushrooms.  See also  inedibles and lookalikes

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The fungus that we know in Australia as a field mushroom is a member of the genus Agaricus.  This is a large genus with a single ancestor (monophyletic) and within the genus is a number of sections each containing a range of species.  While it is tempting to try to assign a species name to any mushroom that you might find, this can be difficult in Australia because many of the species are undescribed or if they are described they aren’t reported in popular guide books.  In addition, it might require the use of a microscope and other detailed analysis.   For our purposes though, it isn’t important to have a name; edibility can be determined by features that can be simply observed.  Our main objectives are:

  • make sure we have an Agaricus
  • Make sure it is not in the section Xanthodermatei

Examples of some well known members of the Agaricus genus are:

Agaricus bisporus – the classic small supermarket mushroom

Agaricus bitorquis – marketed as a larger form of supermarket mushroom

Agaricus arvensis – the almond mushroom or horse mushroom.

Agaricus campestris – the classic if oft mis-identified field mushroom.

This list of features has been put together to assist the average person to identify an edible field mushroom.

1.  Cap colour and texture

The cap of the edible Agaricus species varies from white though dun and on to a slightly pinkish colour in species like A.  sylvaticus.  The cap may be slightly scaley, and may be cracked.  It is always dry and is never slimy to the touch.  Both the colour and texture of the cap are influenced by the environmental conditions as well as the genetics.

Any mushroom with any hint of green in the cap colour should be rejected as this is the colour of the deadly Amanita phalloides.

 top of small field mushroom, typical of those found in lawns (Dave Freer)

top of large field mushroom, similar to supermarket field mushroom (Dave Freer)

top of Agaricus arvenis, showing scales

A forest mushroom, showing red tones on the top

Top of Agaricus bitorquis.  A clean off-white, with undulations

A horse mushroom from the Riverina district of NSW.  Note scales.

A mushroom from a backyard in Penshurst, Victoria, showing some radiating spots.

A mushroom from Digby in Victoria, showing red/brown central region and radiating scales.

2.  Gill colour

The gill colour may vary from brown to pink or off-white in the young mushroom, but it will always darken to a dark brown in a mature specimen.  ‘Not black, but dark brown. Never eat a ‘field’ mushroom with white gills.  This eliminates the poisonous Amanita and Chlorophyllum molybdites.

Pink colour of immature specimen of  a small field mushroom.  Picture courtesy of Dave Freer.

 

3.  Spore print

The spore print is always dark brown.  Not pink, not rusty, not black or purple or white.  Dark brown only.

How do we take a spore print?  Easy.  Place the mushroom, or a piece of it, on a piece of waxed paper and place a glass over the top, with the edge of the jar just propped up by a matchstick or something similar to allow water vapour to escape.  Place in a position away from draughts, overnight.

A simple setup for taking spore print

A spore print of an Agaricus species

4.  The stem snaps away from the cap

The stem of an Agaricus has a texture that comprises a bundle of stringy cells running axially.  The cap has a different texture.  At the point of the junction of these two textures, there is  region where the two will break apart cleanly.  Try this for yourself with a supermarket mushroom.  Note in this mushroom the dark gill colour.

The point of separation should be between the top of the stem and the flesh of the cap.  In some species the stem appears to break away cleanly, but close inspection will show that there is a piece of the flesh from the cap attached to the stem and the position of the separation is actually between the surface of the cap and the flesh of the cap.

This test serves to separate Agaricus from members of the family Cortinaraceae, such as Hebeloma, Inocybe, Cortinarius and Galerina, some of which are seriously poisonous.  It does not separate it from Amanita though.

5.  Smell

Field mushrooms have a distinctive smell that is either ‘mushroomy’  due to a chemical called octenal, or almond/aniseed due to the presence of benzyl alcohol and benzaldehyde.

If the mushroom has a smell of phenol, which is the smell of India ink, or phenyl disinfectant, coal tar soap, creosote or sometimes described as ‘chemical’, then it should be rejected.  Another common product that has the phenol smell is wheelie bin cleaner.  It contains cresols, which are related and smell the same.   Interestingly, and I don’t know why, at high dilutions wheelie bin cleaner smells like Clag glue. Perhaps they use phenol as a preservative.

If in doubt,  there are three approaches you can take;  1) put the mushroom in a plastic bag for 15 minutes and then sniff the contents or  2) heat a piece of the suspect mushroom in a microwave for a minute.  3) Keep one on your desk or other work surface for a few hours.  Sometimes when the smell is not apparent at first it will become apparent over time.  I don’t know what is behind this effect.  The bad smell will become more apparent if there is phenol present as will the almond smell. If you can’t reliably and comfortably identify the smell, preferably with confirmation from someone else, then you should reject the mushroom.

It is often reported that some people can tolerate eating mushrooms that contain phenol.  I did not believe this for a long time but a friend showed me a specimen of what was undoubtedly a yellow staining mushroom from Section Xanthodermatei that a local farming family had been consuming without ill effect.  The identity was confirmed by DNA analysis.  Like many poisons, there is a distribution of susceptibilities in any population and this seems to be an example of that.

Why is phenol a problem and benzaldehyde isn’t?   Because phenol causes acute irritation of the gastrointestinal tract.  This can cause distress and vomiting, but it will pass and will not leave any permanent damage.  Benzaldehyde is a natural product that is a component of almond essence that is used in making marzipan and is without any toxic effects at the doses involved in mushroom consumption. Similarly, benzyl alcohol has low toxicity.

Some poisonous species contain hydroquinone as well as phenol.  This too can also cause gastric upsets. In these ones, both the phenol smell and the yellow colour are not as intense.  The smell should be determined on a fresh specimen at the base of the stem.

6.  Colour of cut or bruised flesh

The colour of the cut or bruised flesh may be brown or red or yellow, or there may be no change in colour at all.  Here for example is an edible mushroom, Agaricus bitorquis, which is showing red on a cut piece.  Photo courtesy of Dave Freer.

Brown or red bruising is usually ok but not an infallible indicator.   A yellow colour may be ok or it may indicate Agaricus xanthodermis, which will cause stomach upsets.  There is much confusion about this.  The yellow colour is an indicator of  A. xanthodermus, which contains phenol, but it does not necessarily indicate an indedible mushroom.   For a diagnosis of an indedible yellow staining mushroom, one needs to have the yellow stain in combination with a phenol smell, as mentioned above. Another term for yellow staining is ‘flavescent’.

The place to determine both the colour and the smell is the base of the stem.  Both features are less prominent in other regions of the mushroom. Don’t be shy, really squash it to get the smell.

Another feature of the yellow staining inedible species is that the yellow colour changes to brown over about an hour.  The yellow colour also intensifies with cooking.  Another test is that the colour intensifies and stays permanent in response to a drop of a 10% solution of potassium hydroxide or the more easily obtained sodium hydroxide which does the same thing. Below is a picture of a mushroom that has been tested with sodium hydroxide.  For some more details on structure and staining in section Xanthodermatei, look here.
yellow stain with caustic

7. Substrate

Field mushrooms will always be found growing from some kind of soil.   They never grow directly from wood and they do not  grow in the middle of cow pats.  There are some deadly species like Galerina that grow from wood and if it is growing from a cow pat, there is a good chance that it is the notorious hallucinogenic ‘gold top’, on the Australian east coast at least.  They do not tend to grow from wood chip or bark mulch either.

Don’t pick and eat mushrooms that grow beside highways or other places where they may have accumulated things like heavy metals or other potentially toxic things.  Mushrooms can be quite good at gathering these things.

8.  Cap shape

Mushrooms of the Section Xanthodermatei, the yellow-staining, phenol containing species tend to have a flat top when juvenile, sometimes continuing to when they are fully grown.  They are often described as having a ‘boxy’ shape.

This, however is not exclusive to this section.  There are many other species that have a similar flat top, and the classic example is Agaricus augustus, known in the US in particular as The Prince, and highly prized as an edible.  So the flat top has limited value as a diagnostic tool.  Sometimes people declare mushrooms to be yellow strainers and therefore inedible based on shape alone without even testing for a yellow stain and smell.  I suggest taking a more thorough approach as outlined above.

9. Tasting

If you are eating an Agaricus that you have never eaten before, try out a small piece first. Sometimes we can be allergic to mushrooms for no apparent reason.   If it tastes horrible, don’t eat it!  This has happened to me with something I expected to taste good.   If you have not experienced any ill effects by the next day, then you can move forward to eating a larger quantity.

Whatever you do, don’t gulp down a huge meal of something that you are unfamiliar with.

10.  One final thing

If, after reading all of the above, you are still not sure, then there is an old mushroom gatherers maxim that applies:

If in doubt – chuck it out

(This picture is repeated as a Facebook catcher)

agricarus 4

Peter Donecker

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