My first recollection of eating field mushrooms [Agaricus bisporus] collected from cattle paddocks just outside of Shannon in 1968. What I recall most about the meal was the ample black liquid that they cooked in and how it turned the toast grey and soggy. This reminiscence was prompted by an article in the business pages of the Dominion Post (Harris 2014) about Clive Thompson, owner of Parkvale Mushrooms in Carterton. Parkvale Mushrooms sells 7-8 tonnes of mushroom a week as well as 50 tonnes of used compost a week and an annual turnover of $3.2m.
New Zealand has 7 commercial mushroom growers producing 8,500 tonnes of mushrooms annually which are worth $41.1 million in domestic sales (Fresh Facts, 2013). Our biggest producer, Meadow Mushrooms in Christchurch, produces on average 147 tonnes of mushrooms a week.
Because fruit rots so easily in a fruit bowl and bread goes mouldy in the bag growing mushrooms should be easy. All you need to do is introduce the fungus to the compost, let it rot and out will pop the mushrooms! Biology is never quite that simple. There is a great article although a little old now written by Stephen Brightwell in New Zealand Geographic in 1993 about commercial mushroom production. For a more recent description see the Mushroom Growers Federation NZ’s website.
The basic process is shown in this diagram from Brightwell (1993).
Compost is made from wet straw, animal manure (usually chicken), and gypsum (calcium sulphate). In a large operation like Meadow Mushrooms the wet straw is heaped into rows and a machine used to turn the composting straw to keep it aerated which helps to maintain a temperature of 65–80°C and to speed decomposition. At this high temperature carmelisation occurs where water is driven out and carbon is concentrated and the compost has a strong smell of ammonia. This is the end of phase I composting.
In phase II composting the compost is kept warm and aerated to promote a second bloom of microorganisms and cause the buildup of heat which will pasteurise the compost. Pasteurisation effective kills any unwanted pests and pathogens of mushrooms. In the cool down period following pasteurisation an array of microorganism flourish which convert any remaining ammonia into protein and other nitrogen compounds the mushroom can use. This is called conditioning of the compost.
When the composts temperature drops to 30°C it is inoculated with fungal spawn. Spawn is made by growing the fungus on cooked rye or other seed. When the seed has been fully colonised by the fungus it is mixed with the compost and the fungus grows out through, colonising, the compost.
The colonised compost is then packed into wooden, stackable trays or onto long metal shelves in mushroom shed where temperature and humidity are controlled for optimal colonisation of the compost. Once this occurs the trays or shelves are cased. Casing is putting a 4-5cm layer of peat and lime across the surface of the compost.
When the casing has been colonised the sheds’ environment is regulated to control the levels of carbon dioxide, humidity and air temperature. Under these controlled conditions mushrooms begin to form. Generally 3 or 4 flushes can be expected over 4-6 weeks.
Once picked the mushrooms are ready for eating. Richard Till’s (2011) recipe is probably as close as it gets to what I remember as a kid.
Mushrooms on toast
½ cup flour
1.5kg cleaned field mushrooms
(or flat cultivated mushrooms)
Melt butter in a large saucepan.
Add flour and stir over a low heat for two minutes.
Add milk and whisk together over a medium heat until the mixture thickens. It will be very thick. Add one teaspoon of salt.
Roughly chop, or crumble the mushrooms into the white sauce, and mix together.
Cover and reduce heat to low. Stir frequently.
The mushrooms will release liquid and the mixture will become quite watery. Remove cover and cook for a further 30 minutes to an hour, until the mixture is thick.
Allow to cool and, if possible, refrigerate overnight.
Reheat and serve on thick slices of buttered toast.
Brightwell S 1993. Feasting on fungi. New Zealand Geographic 18 (June): 34-58. http://www.nzgeographic.co.nz/archives/issue-18/feasting-on-fungi
Fresh Facts 2013. http://www.freshfacts.co.nz/file/fresh-facts-2013.pdf
Harris C 2014. Dream mushrooms into 43m venture. The Dominion Post (1 September 2014): B5. http://www.stuff.co.nz/business/small-business/10444484/Dream-mushrooms-into-3m-venture
Mushroom Growers Federation New Zealand. Myshroom growing process. http://www.mushroomgrowers.org.nz/mushroom-growing-process.php
Parkvale Mushrooms http://www.parkvale.co.nz/index.php
The Profit 2013. Mushroom magic. http://www.theprofit.co.nz/mushroom-magic/
Till R 2011. Man about the land: Magic mushrooms. Sunday Star Times (10 April 2011): E19.
Olwen Mason wrote to me that she had found some mushrooms (4 August) in her garden “near a manuka [Leptospermum scoparium] tree and are entirely purple in the stem, gills and cap and give a creamy white spore print. I think they must be a russula but I haven’t found anything that exactly describes them.”
Based on Olwen’s suggestion that it was a Russula I said it might be Russula macrocystidiata and asked her to send me a photo as the purple gills did not sound right for a Russula.Olwen’s photos show a typical purple funnelcap [Lepista nuda] also known as a blewit. The purple colour is strongest in the young fruit bodies with the purple fading and the cap becoming brown with age. The purple colouring persists in the gills and stem. Olwen also said “I’m surprised by the spore print here which looks more brown/rust than I remembered. I looked at the original and it is the same as the photo so it’s my memory that is at fault.” Her spore print shows the spores to be a buff to pinkish buff. The literature is a bit confusing with some saying the spore print is “whitish buff with possibly a slightly pinkish tint”, “tan to buff spore print”, “light (white to pale pink)”, and “pale pink”.
Tom Volk at University of Wisconsin-La Crosse writes:
Some systematists place Clitocybe nuda into the genus Lepista, because of its tan to buff spore print. However in almost every other way it is a Clitocybe. We accept many shades of spore color in genera like Russula and Pleurotus, so I think we can accept a slight variation in spore color in Clitocybe – I prefer to follow Howard Bigelow, who wrote a monograph of the genus Clitocybe, and use the name Clitocybe nuda. You are free to use Lepista nuda if you like, but I am basically a “lumper.”
While not abundant the purple funnelcap is probably widespread in parks and gardens throughout New Zealand. There is a photo of it from the Wellington Botanic Garden collected in May this year.
Volk T 1998. Tom Volk’s Fungus of the Month for November 1998. University of Wisconsin-La Crosse http://botit.botany.wisc.edu/toms_fungi/nov98.html
Rita Urry sent me photos of these cup fungus, the layered cup, she saw at Otari-Wiltons Bush (21 July 2014) growing on wood chips near the main entrance. I have blogged about this fungus before – Post quake mushrooms.Although this is a small specimen they can get up to 10cm in diameter and with a broad point of attachment to the material it is growing on. They are also often in groups. The fruit bodies are whitish to pale yellow brown but may become pale brown to chestnut brown (Ginns, 1980). The common name, layered, refers the layers that can be seen in the tissue when it is cut and examined under a hand lens.
Ginns, J. 1980. Peziza varia. Fungi Canadenses 169: 1-2.
Latin binomials can be scary enough to the beginner but when those names are the Latinised words from other languages it is even scarier. Take as an example the New Zealand blue pinkgill, Entoloma hochstetteri. Whoa! Where did that name come from and how do you say it? Most can cope with the Entoloma part of the name but in a predominantly English speaking nation why hochstetteri and how do you say it? The simplest pronunciation, although German speakers will shudder, is hock-shtetter-ree.
The blue pinkgill is named in honour of Christian Gottlieb Ferdinand von Hochstetter. Hochstetter was an Austrian geologist and naturalist who visited New Zealand in 1858 to 1860 (Fleming 1990, The Prow 2009). Although his work here was mainly geological he also made notes on natural history including fungi. On returning to Vienna he passed his notes including a drawing of this fungus to the mycologist Erwin Reichardt who describe it as Cortinarius hochsetteri in 1866.
For the first 60 years of the twentieth century there was almost no taxonomic investigation of the mushrooms of New Zealand. This drought was broken by a series of publication by Dr Greta Stevenson who in 1962 re-determined the blue pinkgill as Entoloma hochstetteri. Below is a plate from the 1962 paper with the blue pinkgill lower middle of the plate and numbered 7. The colours are muted due to the poor reproduction from the original art work by the printer and this was a great disappointment to Dr Stevenson.Dr Stevenson’s papers kicked-off a new interest in mushrooms and further popularised through two small pictorial field guides by Marie Taylor. Below are Marie’s original water colours on which the illustrations in her books were based. These books brought awareness of the blue pinkgill to a much bigger audience and it became the ‘must find’ of new forayers. Mary Smiley wrote of her quest for the blue Entoloma of New Zealand in the American magazine Fungi. Mary wrote – crawling through the mud, wet leaves, sticker bushes, on my belly like a Navy Seal on a combat mission but all the while thinking “This is so much fun, I don’t ever want it to end!” and “… there were blue Entolomas everywhere …”.
In the late 1980s the New Zealand Reserve Bank decided to completely revamp our banknotes. After wide consultation with the public the reverse side of the fifty dollar notes now features Pureora forest, the kokako (the blue wattled crow), supplejack whose fruits are eaten by kokako, and the blue pinkgill. As far as I know this is the only currency to feature a mushroom.
The reason for putting the blue pinkgill on the fifty dollar note is artistic in that the blue of the mushroom is similar to the blue wattles of the kokako. The similar colours was also noted by the Tuhoe people who call it werewere kokako or literally the kokako’s wattle (Best, 1942).
In 2002 New Zealand Post issued a set of stamps featuring native fungi with Entoloma hochstetteri on the 80c stamp. This was the first set of New Zealand stamps to feature fungi. The photos were taken by Don Horne.
Our interest in the blue pinkgill is possibly about to go culinary. The Metabolomics lab at the University of Auckland has been researching biological pigments to replace non-biological pigments used as food colourings. As they note:
P.S. 20 March 2015. Banknotes redesign. In November 2014 the Reserve Bank of New Zealand launched a new set of banknotes. Although redesigned they maintained the native biodiversity theme. Note that the blue pinkgill has moved from the lower right hand corner to centre stage.
Food colouring now represents a $1.2 billion global market, with natural colours capturing 31% of the food market, but growing at a rate of 5%. However, these natural colours are largely plant extracts that have the disadvantage of variability and seasonal supply. Microbial cell production, in contrast, offers a reliable and scalable pigment production technology.
Entoloma species are very difficult to grow in artificial culture but the Metaboloic Lab now has the blue pinkgill in culture. It still has to be determined whether or not it has toxic or psychoactive properties. If it hasn’t then one day we may see kokako blue lollies or cosmetics.
The lead researcher Silas Villas-Boas jokes “that if it is edible, blue mushroom risotto could become an iconic New Zealand dish” (Gates, 2013) It would seem however that blue risotto is already a signature dish in Mallorca Spain and in Malaysia.
P.S. 16 July 2014. How we almost lost Hochstetter’s blue pinkgill!
In 1976 Egon Horak studying Entoloma species from around the world concluded Entoloma hochstetteri and the Japanese species E.aeruginosum was the same as an older named species E.virescens. As a result Barbara Segedin noted in 1988 “Hygrophorus cyaneus Berkeley, later called Entoloma hochstetteri by Stevenson and now called E. virescens, described first from Bonin Is., Japan”. Then the Japanese mycologist Tsuguo Hongo (1990) visited New Zealand in the late 1980s and studied both Entoloma hochstetteri and the Japanese species Entoloma aeruginosum and decided that they represented different species thus saving the name for us.
Best E 1942. Forest lore of the Maori. The kokako or crow. http://nzetc.victoria.ac.nz/tm/scholarly/tei-BesFore-t1-body-d2-d6-d16.html
Fleming CA 1990. Hochstetter, Christian Gottlieb Ferdinand von, (from the Dictionary of New Zealand Biography). Te Ara – the Encyclopedia of New Zealand, updated 30 October 2012. http://www.TeAra.govt.nz/en/biographies/1h30/hochstetter-christian-gottlieb-ferdinand-von
Gates C 2013. Mushrooms might yield major value. Stuff.co.nz http://www.stuff.co.nz/science/9354061/Mushroom-might-yield-major-value
Hongo T 1990. New and noteworthy agarics from New Zealand. Report from the Tottori Mycological Institute 28: 129-134.
Horak E 1976. On cuboid-spored species of Entoloma (Agaricales). Sydowia 28: 171-236.
Landcare Research. Flora, fauna and fungi on the other side of our new bank notes. http://www.landcareresearch.co.nz/about/news/blog/flora-fauna-fungi-bank-notes
Metabolomics Lab. Microbe-derived pigments. University of Auckland. http://www.metabolomics.auckland.ac.nz/index.php/home-top/14-projects-detail-cat/52-pigmentsdetail
New Zealand Post. Native fungi. http://stamps.nzpost.co.nz/new-zealand/2002/native-fungi
Reserve Bank of New Zealand. The history of banknotes in New Zealand. http://www.rbnz.govt.nz/notes_and_coins/notes/0094089.html
Segedin BP 1988. An historical view of the larger fungi. Auckland Botanical Society Journal 43: 23-24.
Smiley M 2010. Quest for the blue Entoloma of New Zealand. Fungi 3(4): 4-6. http://www.fungimag.com/fall-2010-articles/NewZealandLR.pdf
Stevenson G 1962. The Agaricales of New Zealand: III. Rhodophyllaceae. Kew Bulletin 16: 227-237 + plates 4-5.
The Prow 2009. Ferdinand Hochstetter (1829-1884). http://www.theprow.org.nz/people/ferdinand-hochstetter-1829-188/#.UpKDBF329D9
Unfortunately it is based on a misinterpretation of the science.
Recent reports claim that “environmental organisations” oppose the removal and use of timber knocked down by storms around Buller and Westland. These people obviously want the climate to warm further from greenhouse gas increases.
When wood rots, it returns its carbon to the atmosphere. In dry climates, the emission is largely carbon dioxide, but in wet ones it is largely methane, a much more powerful greenhouse gas, because rotting is largely anaerobic in saturated timber. Rainforests like those in New Zealand emit enormous volumes of methane and so contribute to the greenhouse effect. They also dump acidic water into the sea, endangering species that need free calcium for their shells.
The best way to sequester carbon is to tum dense timber into furniture and structures that will last for a long time. South Island timbers could be extremely valuable if competently marketed. As a material for furniture and panelling, rimu could exceed teak in value; it’s much more beautiful and easier to work. The Government should approve and encourage the harvesting of downed native timber and its conversion to fine panelling and furniture.
His first point is that under New Zealand conditions these logs will become water logged and begin to decay anaerobically releasing the greenhouse gas methane. When wood becomes so soaked that oxygen is excluded it ceases to decay, it does not switch to anaerobic decay.This is plainly seen in the near perfect preservation of swamp kauri under anaerobic conditions for up to 45,000 years. It is also a common practice to keep harvest logs sprayed with water to prevent the growth of fungi and to prevent decay while they wait to be milled.
Under aerobic conditions, that is when oxygen is freely available, some methane may be produced by wood decay fungi. However research at the Max Planck Institute in German has measured methane production and concluded that the amount of methane produced is so small that its “contribution to global warming is therefore classified as negligible” (Max Planck Society, 2012). The scientist involved has speculated that released methane may be quickly consumed by bacteria found in the decaying wood in close association with the fungus.Potter also says that theses forest dump acidic water into the oceans endangering marine life that need to build shells out of calcium. While some forest rivers are naturally acidic, often called brown or black rivers, the humic and fulvic acids that make them so is an insignificant contributor to acidification. The acidification of the ocean is the result of atmospheric carbon dioxide, from fossil fuel burning and deforestation, dissolving in to it and not from natural river water.
He states that the best way to sequester carbon is to turn it into furniture and structures. One of the major proponent of sequestering wood, at the University of Maryland in the US, has admitted that the removal of dead wood on a large scale would destroy the habitat of organisms, such as fungi and beetles, that breakdown wood and consequently deprive plants of the nutrients released back into the soil (Lovett, 2008). Even the Department of Conservation recognises the importance of decaying logs as providing nursery beds for the next generation of trees. The removal of logs is likely to slow down forest regeneration and it is very likely the resulting forest will be quite different from the existing forest in both structure and species involved.Finally Potter talks of the value of this wood for furniture and panelling. At this stage there is no indication of how much of this salvaged wood is useable as dressed timber. These trees will probably have extensive heart rot, considerable pin-hole borer damage, and to be shattered and fractured by being thrown in the storm. Of the logs salvaged a considerable proportion is likely to end up rotting as wood mulch or being burnt as waste wood releasing the carbon that Potter is so keen to keep locked up.
This wood should be left to lie where it is.
I have written more on this topic here.
Hood, I.A., 1986 (revised 2009). Tree decay. Forest Pathology in New Zealand. http://www.nzffa.org.nz/farm-forestry-model/the-essentials/forest-health-pests-and-diseases/diseases/Tree-decays
Lovett, R. 2008. Carbon lockdown. New Scientist 198 (2654, 3 May 2008):32-25.
Max Planck Society, 2012. Fungi discovered to be source of methane. http://phys.org/news/2012-09-fungi-source-methane.html
New Zealand Forests, 2014. Swamp kauri. http://nzforests.co.nz/
Potter, K. 2014. Environmentalists’ hot air. New Zealand Listener 244 (5 July 2014, 3869): 8. http://www.listener.co.nz/commentary/letters/letters-july-5-issue/
Ridley, G. 2014. At loggerheads. New Zealand Listener 244 (12 July 2014, 3870): 6-7. http://www.listener.co.nz/commentary/letters/letters-july-12-issue/
Stewart, A. 2014. Cyclone Ita devastates West Coast forests. Stuff.co.nz http://www.stuff.co.nz/national/9975198/Cyclone-Ita-devastates-West-Coast-forests
T.E.R:R.A.I.N – Taranaki Educational Resource: Research, Analysis and Information Network, 2008-2014. Fungal mycelia. http://www.terrain.net.nz/friends-of-te-henui-group/fungi-te-henui/fungal-mycelia.html
In mid June the Cawthron Institute in Nelson passed a photo from Nelson College on to me to have a look at. It shows mushrooms sprouting from the base of a shower stall partition. These partitions will be made from a composite wood fibre board sandwiched between water proof outer layers. The board is mounted in an aluminum frame and water and soap scum will have pooled in the joint between the frame and the board and wetting the fibre board and creating a suitable habitat for fungal growth.
The mushrooms are the fruit bodies of a wood decay fungus. It is a species of Pholiota, somewhere near Pholiota aurivella. I am hesitant to say that it is as Pholiota has not been subject of a taxonomic review in New Zealand. Many of the older records refer this fungus to Pholiota adiposa for instance in Birch’s A synopsis of forest fungi of significance in New Zealand published in the 1937:
However, Egon Horak (1971) examined the material and noted that it closely fitted Pholiota aurivella.
Marie Taylor (1981) published a picture of what she called Pholiota sp. aff. adiposa. The ‘aff.’ simply means like but not the same as adiposa. Marie described it as:
Has lemon coloured, very glutinous caps covered with brown scales floating in the gluten and scaly patches also covering the stem below the ring. The species is found often on lacebark (Hoheria) wood.
Ian Hood (1992) also called it Pholiota adiposa but said that the spores where too big and that further study was needed. Ian gives the habitat as podocarp broadleaf forest occurring on stumps and logs and also living trees, such as Hoheria angustifolia.
The final Photo is by Don Horne.
Birch, T.T.C. 1937. A synopsis of forest fungi of significance in New Zealand. New Zealand Journal of Forestry 4: 109-125.
Hood, I.A. 1992. An illustrated guide to fungi on wood in New Zealand. Auckland University Press: Auckland, New Zealand.
Horak, E. 1971. A contribution towards the revision of the Agaricales s.l. (Fungi) of New Zealand. New Zealand Journal of Botany 9: 402-462.
Taylor, M. 1981. Mushrooms and Toadstools. A.H. and A.W. Reed Ltd: Wellington, New Zealand.
The Minister for Conservation, Nic Smith, said that “’It is a tragedy that so much forest has been wrecked by Cyclone Ita but no good purpose is served by leaving it all to rot” and that he was grateful for the “common sense support” from United Future and the Maori party that ensured that bill was approved under urgency. The recovery of timber will only occur for proposals that ensured worker and public safety and have minimal impact on the environment.For many New Zealanders environmental impact is limited to trees and birds and this is reflected even in the name of our oldest conservation society – the Royal Forest and Bird Society. What tends to be forgotten is the importance of all of the other organisms that make the biological diversity in a forest or worse those organisms and their activities are seen in a negative context, i.e. that decomposers serve no good purpose. In these days of the loss of vast areas of forest, and its associated biodiversity, around the world this is an extraordinary comment by anyone let alone a Minister responsible for the conservation of biodiversity. The importance of deadwood for conservation of biodiversity in European forests was highlighted in a report released by the World Wide Fund for Nature (WWF) in 2004 [Deadwood – living forests. The importance of veteran trees and deadwood to biodiversity]:
Up to a third of European forest species depend on veteran trees and deadwood for their survival. Deadwood is providing habitat, shelter and food source for birds, bats and other mammals and is particularly important for the less visible majority of forest dwelling species: insects, especially beetles, fungi and lichens. Deadwood and its biodiversity also play a key role for sustaining forest productivity and environmental services such as stabilising forests and storing carbon.
It would be unlikely that New Zealand forests would be different.
Sporadic catastrophes are a key feature of the structure and therefore the ecology of New Zealand forest. Glenn Stewart wrote that the forest structure and species composition of west coast forest where the result of:
infrequent, massive earthquakes are the dominant coarse-scale disturbance agent, triggering episodes of major erosion and sedimentation and leaving a strong imprint in the forest structure. In other forests, flooding and catastrophic windthrow are major forms of disturbance.
And the importance of dead wood in forest regeneration after harvesting to mimic catastrophe:
The importance of logs as nursery sites for new trees is well known. But what is forgotten is the importance of fungi and other decomposers in transforming a log into suitable material for seedling growth. In all likelihood, as a result of this legislation, these forest will be slower to regenerate and be of a different structure and diversity because the trees were not left to for fungi to rot.
Any harvesting should recognise the importance for tree establishment of: forest floor microsites, such as fallen logs and tree tip-up mounds.
Mathewson, N. 2014. Storm-blown native timber will be recovered. Stuff.co.nz
Stewart, G.H. 2002. Structure and canopy tree species regeneration requirements in indigenous forests, Westland, New Zealand. Department of Conservation, New Zealand – DOC Science Internal Series 66.
Wassilieff, M. 2013, Forest succession and regeneration – beech and conifer forest regeneration. Te Ara – the Encyclopedia of New Zealand.
WWF, 2004. Deadwood – living forests. The importance of veteran trees and deadwood to biodiversity.