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Growing your own mushrooms – A Miller’s tale

Cultivation of the common field mushroom began in France in around 1650. The technique was transferred to England when detailed instructions were published in The Gardener’s Dictionary, first published in 1731 by Philip Miller. That’s him in the picture above, somewhat enhanced by modern photo editing techniques. Quite an accomplished man, he was a Fellow of the Royal Society.

It seems that this was quite a popular pursuit in the day and that the technique may have been introduced into Australia with the first English settlers. In the Swan River Colony of Western Australia, which was first settled in 1829, there is a comment made by James Drummond in 1845 that the common field mushroom has become established in the colony following its cultivation. It is likely that the species cultivated reflect what was growing wild in England at the time.

People often ask in online forums if it is possible to grow mushrooms from wild ones that occur in their lawns etc. This method details a technique for doing exactly that.

The book is available online as a PDF download courtesy of Google. I have taken that PDF and used OCRbest to extract the information in text form. It did a very good job. In those days an ‘s’ looked rather like an ‘f’ so I have had to weed out those occurrences. I hope that I got them all. I have made some minor edits to allow the text to be broken up into shorter paragraphs. Anyway, I reproduce his method below. Good luck to anyone who wants to try it.

Philip Miller’s Mushroom Growing Method

MUSHROOMS are, by many persons, supposed to be produced from the putrefaction of the dung, earth, etc. in which they are found ; but notwithstanding this notion is pretty generally received amongst the unthinking part of mankind, yet by the curious naturalists, they are esteemed perfect plants, though their flowers and seeds have not as yet been perfectly discovered. But since they may, and are annually propagated by the gardeners near London, and are (the esculent form of them) greatly esteemed by most curious palaces, I shall briefly set down the method practised by the gardeners who cultivate them for sale. But first, it will not be improper to give a short description of the true eatable kind, since there are several unwholesome sorts, which have been by unskilful persons gathered for the table.

The true Champignon, or Mushroom, appears at first of a roundish form, like a button; the upper part of which, as also the stalk, is very white; but being opened, the under part is of a livid flesh colour, but the fleshy part when broken is very white ; when these are suffered to remain undisturbed, they will grow to a large size, and explicate themselves almost to a flatness, and the red part underneath will change to a dark colour.

In order to cultivate them, if you have no beds in your own, or in neighbouring gardens, which produce them, you should look abroad in rich pastures, during the months of August and September, until you find them (that being the season when they are naturally produced then you should open the ground about the roots of the Mushrooms, where you will find the earth, very often, full of small white knobs, which are the offsets, or young Mushrooms; these should be carefully gathered, preserving them in lumps with the earth about them : but as this spawn cannot be found in the pasture, except at the season when the Mushrooms are naturally produced, you may probably find some in old dunghills, especially where there has been much litter amongst it, and the wet hath not penetrated it to rot it.

Likewise, by searching old hot-beds, it may be often found; for this spawn has the appearance of a white mould, shooting out in long strings, by which it may be easily known wherever it is met with : or this may be procured by mixing some long dung from the stable, which has not been thrown on a heap to ferment; which being mixed with strong earth, and put under cover to prevent wet getting to it, the more the air is excluded from it, the sooner the spawn will appear; but this must not be laid so close together as to heat, for that will destroy the spawn : in about two months after the spawn will appear, especially if the heap is closely covered with old thatch, or such litter as hath lain long abroad, so as not to ferment, then the beds may be prepared to receive the spawn.

These beds should be made of dung, in which there is good store of litter, but this should not be thrown on a heap to ferment; that dung which hath lain spread abroad for a month or longer, is best. These beds should be made on dry ground, and the dung laid upon the surface; the width of these beds at bottom should be about two feet and a half or three feet, the length in proportion to the quantity of Mushrooms desired; then lay the dig about a foot thick, covering it about four inches with strong earth. Upon this lay more dung, about. ten inches thick; then another layer of earth, narrowing in the sides of the bed, so as to form it like the ridge of a house, which may be done by three layers of dung and as many of earth.

When the bed is finished it should be covered with litter or old thatch, to keep out wet, as also to prevent its drying; in this situation it may remain eight or ten days, by which time the bed will be in a proper temperature of warmth to receive the spawn; for there should be only a moderate warmth in it, great heat destroying the spawn, as will also wet; therefore when the spawn is found, it should always be kept dry until it is used, for the drier it is, the better it will take in the bed; for I had a parcel of this spawn, which had lain near the oven of a stove upward of four months, and was become so dry, that I despaired of its success; but I never have yet seen any which produced so soon, nor in so great quantity as this.

The bed being in a proper temperature for the spawn, the covering of litter should be taken off, and the sides of the bed smoothed; then a covering of light rich earth about an inch thick should be laid all over the bed, but this should not be wet ; upon this the spawn should be thrust, laying the lumps four or five inches asunder ; then gently cover this with the same light earth above half an inch thick, and put the covering of litter over the bed, laying it so thick as to keep out wet and prevent the bed from drying! when these beds are made in the spring or autumn, as the weather is in those reasons temperate, so the spawn will then take much sooner, and the Mushrooms will appear perhaps in a month after making; but those beds which are made in summer, when the season is hot, or in winter, when the weather is cold, are much longer before they produce.

The great skill in managing of these beds is, that of keeping them in a proper temperature of moisture, never suffering them to receive too much wet: during the summer season the beds may be uncovered, to receive gentle showers of rain at proper times, and in long dry seasons the beds Should be now and then gently watered, but by no means suffer much wet to come to them ; during the winter season they must be kept as dry as possible, and so closely covered as to keep out cold.” In frosty or very cold weather, if some warm litter shaken out of a dung heap is laid on, it will promote the growth of the Mushrooms; but this must not be laid next the bed, but a covering of dry litter between the bed and this warm litter ; and as often as the litter is found to decay, it should be renewed with fresh; and as the cold increases, the covering should be laid so much thicker. If these things are observed, there may be plenty of Mushrooms produced all the year, and these produced in beds, are much better for the table than any of those which are gathered in the fields.

A bed thus managed, if the spawn takes kindly, will continue good for several months, and produce great quantities of Mushrooms; from these beds when they are destroyed, you should take the spawn for a fresh supply, which may be laid up in a dry place until the proper season of using it, which should not be sooner than five or six weeks, that the spawn may have time to dry before it is put into the bed, otherwise it will not succeed well.

 Sometimes it happens, that beds thus made do not produce any Mushrooms till they have lain five or six months, so that these beds should not be destroyed, though they should not at first answer expectation; for I have frequently known these to have produced great quantities of Mushrooms afterward and have continued a long time in perfection.

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Leucocoprinus birnbaumii – the flowerpot mushoom

One of the most commonly asked questions on mushroom forums is “What is this yellow mushroom in my flowerpot”. The mushroom they are referring to is Leucocoprinus birnbaumii. This is one of a number of closely related species that are associated with potting mixes.

It is a fleeting mushroom, appearing as a small yellow lump then growing into a small parasol shape before sinking back into the substrate. Part of this process is caught in the video below, reproduced with kind permission of Thomas Phoon Kong Wai of Singapore.

This mushroom was first described by British mycologist James Bolton in his book ‘A History of Fungusses growing about Halifax‘ published in 1788. He gave it both a common name, ‘Yellow Cottony Agaric’ and a botanical name, Agaricus luteus, seen on the left.

Unfortunately, the name he gave it, Agaricus luteus was already in use so his nomenclature did not fit with the rules and it fell to Czech mycologist Augustus Corda who found it growing in a greenhouse in Prague to name it after a garden inspector called Birnbaum.

I was rather intrigued by the note that Bolton made regarding it being found in a pine-stove. I had no idea what a pine stove was but further investigation reveals that the growing of pineapples was all the rage in England and Scotland at the time and wealthy people constructed hothouses with elaborate heating systems in which to cultivate them in the cold climate. One elaborate monument to this fad is this construction by John Murray, the 4th Earl of Dunmore which you can visit in Scotland.

Chemistry

The intense yellow colour of these mushrooms is due to two alkaloids known as birnbaums.

The structure of these compounds was determined by Bartsch et al. in 2005. This work is in some places referenced with the comment that these compounds are toxic but if one reads the paper there is no such mention of toxicity. A review by Rani and Granchi in 2015 also notes that there is no biological assessment of these compounds.

In fact this mushroom is widely described as toxic but the reality is that there is no data available anywhere to support this claim. Considering that this is such a common mushroom, one might expect some records of toxic effects to be recorded but there is nothing. Given that these are often found in indoor settings, they are the sort of things that pets might occasionally nibble on and in fact I noticed one such case on the Emergency Identification for Plants and Fungi page on Facebook. In this case a dog in Australia had eaten one. Inquiries with the vet revealed however that there was no indication of the dog suffering from toxic effects.

I think that this is one of those cases of the propagation of mushroom myths like the old chestnut about Coprinus comatus being poisonous if consumed with alcohol. It probably has its origins in the fact that this mushroom was at one stage grouped with the Lepiotas which do contain species that are deadly poisonous. I think that consumption of a small mushroom like this would be pointless and I would not recommend it but one member of a group I admin reported that he had eaten them.

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A missing Western Australian ‘Death Cap’ Amanita?

I was interested to read about some people in Rwanda who eat large quantities of a mushroom from the genus Amanita that grow in the Eucalyptus plantations there. This mushroom is called Amanita bweyeyensis. There is a YouTube video on the subject, from which this image is clipped.

Peeling Amanita bweyeyensis before consumption


https://www.youtube.com/watch?v=PtjRvTmg3GY

This mushroom sits within the Phalloideae section of Amanita, where the deadly species containing amatoxins reside. Despite this, it does not contain amatoxins nor phallotoxins. It is the amatoxins that are the cause of many fatalities when people eat other mushrooms in this section such as Amanita phalloides. Phallotoxins are not orally active so pose less of a threat.

DNA analysis shows that this mushroom sits within a small cluster that includes the white “death cap” mushrooms from Western Australia. These are: A. djarilmari, A. eucalypti, A. gardneri and A. marmorata. The partial phylogenetic tree is from this paper: https://mycokeys.pensoft.net/article/34560/zoom/fig/11/

Analysis of the Western Australian species has shown that these do not contain amatoxins either. This is reported in a paper that is behind a paywall but the precis is shown at this link.

American Amanita expert Debbie Viess advises that these mushrooms would be called ‘Destroying Angels’ rather than ‘Death Caps’ according to US word usage.

This is a picture of the Amanita bweyeyensis from the paper mentioned above. Unfortunately, I can’t show pictures of the Western Australian species.


Since the African species sit so close to the WA species in terms of genetics and they grow in Eucalyptus plantations, it is tempting to think that they might have their origins in WA. If this is the case, they do not seem to have been recorded here. It is hard to know where the Eucalyptus trees planted in Rwanda came from originally; they are not WA natives but it is not beyond the realms of possibility that they came from Western Australia, given that this is the closest state to Africa.

This brings to mind the green Russulas that grow in the Eucalypt plantations in Madagascar which are eaten by the people there. They also peel those mushrooms before consumption. These Russulas are unknown in Australia though it would seem likely that is their origin.

How are amatoxins produced?

The production of amatoxins has been investigated in some detail by Heather Hallen and others in terms of genes. It has been shown that the amatoxins originate from proproteins synthesised on the ribosome. The function of the ribosome is shown in this rather cute image which is by SITNBoston and is taken from the Harvard University Site.

The codon carried on the mRNA (we all know what this is these days!) is decoded in the ribosome and amino acids carried by tRNA are converted into an amino acid chain which is known as a proprotein. This is similar to the process by which the covid spike proteins are produced by the mRNA vaccines.

These proproteins have a size in the range of 34 to 35 amino acids whereas the toxins have a size of 8 amino acids. In order for the amatoxins to be produced, these long chains need to be reduced in size and the fragments cyclised. This process has been studied in the amatoxin-producing genus Galerina by a group of researchers and the process is shown in this image from that publication.


The proproteins are acted on by the prolyl oligopeptidase enzyme which cuts the chain at the Proline amino acid and then stitches together the piece that is clipped out to form the bicyclic polypeptides (2 rings of amino acids) that we know as amatoxins.

The amatoxins are bicyclic (=two rings) octapeptides (=contain 8 peptides) with C-to-N (head-to-tail) condensation of the peptide backbone and a cross-bridge between Tryptamine(Trp) and Cisteine (Cys). Three of the amino acids (Trp, Pro, and Ile) are hydroxylated. Phallotoxins are similar in structure but their macrocycles comprise only seven amino acids. The relationship between the different amino acids is shown more clearly in this labelled diagram.

The image below shows a 3D view of an amatoxinA molecule in a similar orientation to the image above. The yellow sulfur atom can be seen within the structure and the 5-membered nitrogen-containing hetercyclic ring of (hyroxylated) Proline (P) seen on the left hand side with the (hydroxylated) Isoeucine (I) skeleton above it and Asparagine(N) below it. There is also a bridge with the (hyroxylated) Tryptamine sitting in the middle of the structure which is facing out into the page.

Amatoxin A molecule

This type of structure is very stable and survives heating and the action of digestive enzymes. That is one of the reasons that this type of toxin is so dangerous.

Just why this group of mushrooms does not always produce these toxins doesn’t seem to be well understood. I am informed by Debbie Viess that specimens of Amanita marmorata taken from the same region have tested positive in one case and negative in another.

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Amanita rubescens – The Blusher – an introduced species

The early colonists of Australia were mainly of British origin and they brought with them the trees with which they were familiar.  Such trees include pines and oaks.  With these trees came the fungi that were associated with the roots of the trees.  There are quite of few of these fungi that have now become established in various areas in Australia.  One of these is the infamous Death Cap, Amanita phalloides.

Because of the lethal consequences of eating Amanita phalloides, people have a natural caution about eating anything in the Amanita genus.   This includes some of the most enthusiastic mycophagists, including myself.

I had not been aware of any edible Amanitas in Australia until I heard of Amanita rubescens.  It occurs in the Adelaide hills and in Queensland and probably in places in between.  My encounter with it was in the Adelaide hills.  It was growing in a park filled with oaks and pines and in this case I believe it was growing on the oaks.  Here is what it looks like in its various stages of growth.

rubes

Amanita rubescens at various stages of growth.

Some important general features are the lack of a volva at the base and the presence of ‘warts’ on the surface of the mushroom.  When it is broken open or cut, the white flesh and gills take on a red/pink colour as shown in the next picture.

img_0067

Amanita rubescens showing red bruising

There are not too many mushrooms that this could be confused with.  The main one that crops up in the literature is Amanita pantherina.  A distinguishing feature of A. rubescens that sets is apart from A. pantherina is the presence of striations on the annulus.  These are shown in the picture below. You can also see the pink colour of the broken flesh of the cap there.

img_0074

Striations on annulus of Amanita rubescens

This mushroom is known to contain a toxic, haemolytic protein that is destroyed by cooking.   This in mind, I cooked some up on a barbecue until they were quite soft.  In fact they were so soft that they did not really appeal much.  This being my first taste of a new mushroom, I tasted the cooked material without swallowing it.  The taste reminded my a bit of Volvopluteus.   I have read reports that it is better cooked hard until it starts to brown.  This is the case with many other mushrooms.

It is scary eating an Amanita for the first time.  People who I know and respect regarding edible mushrooms in Australia cannot bring themselves to eat this one.  My caution was brought into sharp focus the next morning when I felt decidedly ill.  I don’t actually think that this was the mushrooms, as I had felt a little ill the night before with food from the place where I was staying.

I will try this again, next time with hard cooking.

I would like to thank my friend Kate for giving me the heads up about these.  You can see her interesting site about foraging  here. She is in South Australia and really knows her mushrooms.

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Lactarius deliciosus – Saffron milk cap – an east coast favourite.

The Saffron milk cap is a mushroom that occurs widely on the east coast in pine forests.  Foragers are actively encouraged to pick this mushroom in NSW in places like Oberon.  It also occurs in Victoria, South Australia and Tasmania.  Reports from Queensland are rare but it is occasionally found there. Sadly, it is not something we see in the pine forests of WA, though there have apparently been unsubstantiated reports of it from the Kewdale area, according to Bougher and Syme (1998).  There is another mention of someone trying to establish this in WA in an earlier paper. I have certainly never seen it in WA.

To view one of these beauties I had to travel to Adelaide on a heads up from some friends there.  These were cropping up in early February of 2017 after some rain, to the general surprise of enthusiasts there.  There were not a lot of them at this time, but I did manage to find this single specimen, to my great joy.  Thanks to Kate et. al. for the heads up!

This is what it looks like from the top.  Notice the pine needles.

saffie
Lactarius deliciosus cap

When cut, the inner surface reveals an orange colour at the margins, as shown below.

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Lactarius deliciosus showing red cut surface

Some texts say that these mushrooms are not particularly good eating and that the name is in fact a misnomer.  To test this out, I took my specimen down to a the barbecue at a local park in suburban Adelaide and fried it up with a little olive oil.  Adelaide is so well endowed with such parks and barbecues and I am sure that they are a popular gathering place. On this particular day however there was nobody else around though, and perhaps that is because it was 42 degrees. All this reinforces the oddity of finding mushrooms at this time of year.

Anyway, back to the taste test.  I found that the smell and the taste were intimately entwined and that it was a pleasant and unusual taste.  It is hard to describe a smell or taste but I kept thinking of vegetables like carrots.  This may well have been influenced by the orange colour.  The other very distinctive and great thing was the firmness. This is easily the most firm mushroom that I have ever cooked and eaten.

I look forward to eating more of these.  Who knows, perhaps they might crop up in WA?  Time will tell.

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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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