Archive for Potential edibles

Rhizopogon – a taxonomic challenge

A walk in a pine plantation in WA during winter will often reveal a truffle-like fungus lying on the top of the ground or sometimes almost buried.

rhizopogon-pseudoroseolus

Rhizopogon pseudoroseolus

This is Rhizopogon, introduced with the pine trees and a very effective fungus for assisting the pines to grow.  The mycelium from fungi such as these acts as an extension of the roots of the trees, drawing in nutrients that would otherwise be unavailable to the trees.

Many sources report that the species occurring here are Rhizopogon luteolus but DNA results on the specimen pictured above match R. pseudoroseolus (GQ267483).  This species, an introduction from the USA is also very common in New Zealand, though the appearance does not appear to match either the image nor the key published by Jerry Cooper of the Fungal Network of New Zealand. There are many different species, lots of variability and many published revisions of this genus so it does make identification difficult.

In Japan, a member of this genus, Rhizopogon roseolus is much prized as a food where is it known as Shoro.  The Kiwis, always much more proactive on these matters than we are, have done some comparisons on the species growing in New Zealand with those in Japan and have gone so far as introducing the Japanese species into NZ as a potential agricultural product.

This is not an easy fungus to identify visually and there is sparse information about edibility.  My friend Jsun has eaten a species that grows in Queensland and while visiting here he pickled some that I had collected.  These are shown in the picture below.  He has selected specimens that were firm and had a white interior when cut in half. When pickled, the outside became quite distinctly reddish.

rhizopogon-jar

Pickled Rhizopogon pseudoroseolus

I have eaten small quantities of these and must say that they are rather bland. Jsun reports that he likes to add them to stews and so forth and that they soak up the flavor of the dish.

See also: https://mushroaming.wordpress.com/2015/12/26/rhizopogon-rubescens/

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Laetiporus portentosus -White punk, poor tucker indeed

There have been many reports from the times of early European settlement, all from Tasmania, of the Aboriginal people eating a white’ punk’ growing on trees.  It has been widely assumed that this is Laetiporus portentosus, formerly known as Piptoporus portentosus.

This June I chanced upon a specimen of this lying on the ground in Bridgetown.  It was quite a massive thing, weighing several kilos and it was saturated with water.  That is why I assume was on the ground, having fallen from its position because of its weight.  Here it is sitting on my dining room table.

Laetiporus portentosus desk

Fallen Laetiporus portentosus on table

 

Here is another shot of it, this time showing the inside after I had cut it open with great difficulty.  I don’t think this would have been possible with primitive tools.

Laetiporus portentosus cut

Laetiporus portentosus cut open

You can see that the inside looks sort of cottony.  In fact it more closely resembles polystyrene in texture.  An attempt to eat a small piece of it revealed that it was about as edible as polystyrene too.  Not even in an emergency could anyone possibly eat and digest this fungus.  Perhaps the story is different with very small specimens but I am doubtful.

It is quite difficult to get a picture of one of these in-situ on a tree because they tend to grow quite high up.  I was lucky enough to spot one by a road cutting near Donnybrook that enabled me to scramble up and take a picture with my phone.  Here it is.

laetiporus donnybrook

Laetiporus portentosus in situ

The fact that these are relatively few and far between and so high up on the trees is further evidence against them being used as food.

It is however widely reported that they were used as tinder and to carry fire.  Some experiments revealed that a dried specimen could be ignited very readily and that it would smolder for a long time.  By judicious control of the fire front on a smoldering specimen it could easily be kept aglow for hours.  Uncontrolled burning of half a specimen lasted about 40 minutes.  I made a short video of a small piece smoldering after it had been ignited. A still from that video is shown below.

laetipurus glowing

A piece of Laetiporus portentosus smoldering

 

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Amanita muscaria – just for the hell of it

nibble

This mushroom needs no introduction, although most people in Western Australia will not have encountered it in the wild.   In fact, the first confirmed occurrence of this mushroom in WA was only comparatively recently in 2009.  See First record of Amanita muscaria in Western Australia.

That paper expresses some concern about this spreading to pine plantations in WA, where I in fact first encountered it.  Unlike the situation in other states, this fungus was not purposely introduced into pine plantations.   It has been demonstrated to be capable of transferring to many of our native trees in SW WA under laboratory conditions, which is of some concern to mycologists it seems. Since the initial sighting, it has been recorded in many places from Perth to Augusta.


Note: May 2016

I am watching this spread through the pine forest where I first encountered it and I have found it invading one section of the pines in the local arboretum.  It is apparently common around Margaret River

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I have known for some time that this mushroom was edible if treated appropriately, so with some specimens in my hand, I decided to research the topic.   My research yielded a paper by Rubel and Arora.

They point out the wide cultural bias against eating this mushroom and point out that the toxic components are water soluble.  They suggest a technique of boiling the thinly sliced mushroom in a saline solution for 15 minutes.

In contrast to that paper, Debbie Viess has published several papers that vehemently oppose the concept of eating this mushroom, though by her own admission, she has tried it.

After reading what was available, it seemed to me that the Viess papers really served to reinforce the cultural bias suggested by Rubel and Arora.  The suggested boiling regime did not seem overly complex as suggested by Viess, and discarding the water didn’t seem like too much of a burden.  So I decided to conduct my own investigation.

Erring on the side of caution, I cut up a single cap into slices of 3 to 4 mm thickness and boiled them for 15 minutes in salted water.  I then drained them and repeated the procedure, finally rinsing the slices in cold water.   After this treatment, there was no red colour remaining, and the slices were of limp, unappealing appearance.  However, I fried them up in a little butter/oil mix until they were slightly brown and found them to be quite tasty.

What troubled me was the lack of actual data regarding the rate of removal of the toxins, so I decided to do my own investigation.   It seemed to me that if the toxins are readily water soluble, then one might expect to see some change in the conductivity of the extraction solution.   So I sliced up a single cap, weighing 45g and placed it in 1 litre of water.   The conductivity immediately rose from 31 microSiemens to 60 microSiemens. I then began to heat the combination until it boiled and maintained it at a steady boil for 3o minutes, allowing it to rest for a further 30 minutes.   During this procedure, I took 10 ml samples with a plastic syringe and added them to 100ml of cold water, measuring the conductivity of the resultant solution.  From this  I could calculate the conductivity of the hot water solution.  I repeated this exercise with another cap of 40g weight which I pulverised with a blender for 2 minutes.  My results are shown below.

graph

The blue line shows the conductivity of the solution for the case of sliced caps and the red line shows the result for the pulverised caps.  The higher starting point for the pulverised caps shows that the finer particle size provided more rapid leaching.  This indicates that diffusion of the soluble components from the mushroom mass is rate controlling.  Hence the need for thin slicing and boiling.

I had no means of determining the actual amount of soluble toxin in the solution, but since these toxins are highly soluble, I expect that they would follow the trend with the total soluble components.  It would seem that a photometric measurement in the deep ultraviolet region at 254nm would be needed to follow the amount of ibotenic acid and muscimol in the solution.

I should note that I have not taken into account the lowering of the volume of the boiling water during the extraction process.   Because of this, my readings are higher than they should be.  Despite this, they do show that there is a fairly rapid increase in extraction in the first 15 minutes followed by a reduction in the extraction rate.

From my point of view it would be preferable for someone better equipped than myself to conduct experiments along these lines and to publish the results than to go to the extraordinary lengths that Ms. Viess has gone to in the way propagating fear of the unknown. In any case, I can report that I have consumed about 10 grams of the boiled slices without any ill effect whatever.

I wonder how the kangaroo that took the nibble out the specimen pictured above is feeling?

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PS  There is a description of what happened to some people who only boiled the mushrooms for 3 minutes at this link.

Prue in Tasmania reports pickling these. She has given a link below.

Debbie Viess has taken the time to add a comment below as well.

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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.

 

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

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Boletes – a lost resource

“Few orders of plants appear to contribute more to the support of animal life in Western Australia.  Many species, Particularly, the genus Boletus, are used as food by the natives and directly supply no inconsiderable portion of their support for several months a year.”

James Drummond, the pioneer botanist of WA.

This quote is from an article by eminent mycologist Roger Hilton, in a short article about edible fungi he wrote in the journal Landscope in 1988.

In Western Australia there is a large number of boletes that spring up each Autumn.  Judging from overseas experience, it is likely that a lot of these are edible species, but all of the knowledge of Aboriginal consumption of these fungi sadly has been lost.

Hilton comments there are boletes that will make you sick, but none that are known to be lethal like the Amanitas.   However, there has been one recorded case of a fatality from eating a bolete.  In this case it was from muscarine in the mushroom. 

From time to time, I experiment with some of the many boletes that spring up on my property.  My standard test is to lightly fry a few small slices in some oil and do a taste test.   By this means, I have been able to eliminate a few as being too revolting to consider.   There remain others that are tantalisingly tasty.  I tried one a few hours ago.   It was a handsome specimen with firm white flesh and a black cap.   When cooked in this way, it produced a wonderful tasting type of crisp.  So far, I am feeling no ill effects from the very small pieces that I tasted.   But this is not for the faint-hearted!   Over the years, by cautious exploration, I hope to be able to find one or two boletes that are edible.  I would rather be using a gas chromatograph for the initial assessments, however.

Presently, the only boletes that are known to be edible are the Slippery Jacks and Phlebopus marginatus, the Salmon Gum mushroom which often appears in the news because of it’s giant size.

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Agrocybe parasitica

At the top of my list of edible mushrooms that I have not tried is Agrocybe parasitica.  That is because it is a large mushroom and can occur in fairly large clusters.  It should also be possible to cultivate this mushroom.

 

Above picture is courtesy of Reiner

Various sources disagree with respect to the edibility of this mushroom.  None list it as poisonous, but some advise caution.  On the other hand, Watling and Taylor (1987) describe it as an excellent edible.  Their description can be found here.

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