American Skunk-cabbage, Lysichiton americanus

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At the beginning of April I met an old friend, American Skunk-cabbage, Lysichiton americanus, in a wet woodland at Buckenham in Norfolk. I was on a BMS (British Mycological Society) foray. Fungi were few but seeing American Skunk-cabbage was a highlight of the day.

I hadn’t seen the plant for several years but I had strong memories of its magnificence and it didn’t disappoint. It is stunning!

American Skunk-cabbage,Lysichiton americanus

American Skunk-cabbage, Lysichiton americanus, Buckenham, Norfolk, 5th April 2025.

There is something almost alien about American Skunk-cabbage’s big, bright yellow flowers, which emerge in April, slightly ahead of the leaves. It is bigger and bolder than our own Cuckoo Pint, Arum maculatum, which I wrote about in March 2018, though clearly related.

Both plants are members of the family Araceae and have flowers borne on an inflorescence known as a spadix, partially enclosed in a sheath (a leaf-like bract known as a spathe).

The spadix emits a scent to attract pollinators and in Lysichiton americanus this is a musky smell to attract adult rove beetles. The smell resembles the spray of skunks (note 1), hence “Skunk-cabbage”. I’ve never seen or sniffed a skunk so the smell reminded me of plastic with an added top note of Fox and I found it intriguing rather than unpleasant. (The Oxford Plants 400 website is less complimentary, describing the scent as “unpleasant, faeces-like, indole-rich“.)

Insects are often attracted to yellow objects and the bright yellow spathes of the plants at Buckenham were attracting sunbathing flies, including Eristalis hoverflies. I also noticed a few Owl Midges inside one flower (note 1).

American Skunk-cabbage, Lysichiton americanus

American Skunk-cabbage, Lysichiton americanus, attracting flies.

The genus name Lysichiton is derived from two Greek words: lysis, meaning dissolve, and chiton, meaning a cloak or armour. These describe the way that spathe enclosing the inflorescence withers soon after flowering (note 2).

Lysichiton flowers are hermaphrodite but individual plants have male and female phases. The spathe is protogynous – the flowers start off functionally female and then become male.

Lysichiton americanus is, as the specific name suggests, native to America, particularly western North America  from Alaska south to California, where it is known as Western Skunk-cabbage (note 3).

Native American tribes would sometimes eat parts of the plant but not raw. Like our native Cuckoo Pint, American Skunk-cabbage contains calcium oxalate crystals (raphides). Thorough cooking or drying can make it edible but I’m not tempted. Statements like “the native North American Indian tribes would cook [the leaves] in several changes of water, the end result being a tasteless mush” don’t make me want to experiment.

Encounters with Skunk-cabbage

American Skunk-cabbage has been introduced to several European countries: Belgium, Denmark, Finland, Germany, Great Britain, Ireland, Netherlands, Norway, Sweden and Switzerland. It is a plant of stream sides, boggy places and swampy woodland in both its native and introduced range.

American Skunk-cabbage, Lysichiton americanus

American Skunk-cabbage, Lysichiton americanus, in the bog garden at Forde Abbey (27th April 2008). Some of the spathes have withered.

My first encounter with American Skunk-cabbage was in the wonderful Cruickshank Botanic Garden in Aberdeen, when I was studying Botany in the early 1980s. I often visited the garden at lunchtimes and sometimes shared a sausage roll with the gardener’s dog, a golden retriever with an expression that even a penniless, hungry student couldn’t refuse. In spring, the stunning yellow flowers of Lysichiton americanus were one of the many highlights of the garden (note 4).

I have vivid and happy memories of my time in Aberdeen but sadly no pictures of Lysichiton americanus. But when I saw the plant in 2008, when we visited Forde Abbey, near Chard in Somerset, I did take some photographs. It was late April and Lysichiton americanus was flowering in the bog garden. The clumps of glossy, leathery foliage give the plant a passing resemblance to a cabbage.

Even when Lysichiton americanus has finished flowering, its leaves are very distinctive and noticeable. When we stayed in Oban in May 2018 we recognised American Skunk-cabbage plants on the banks of a stream on the road north of the town to Ganavan Sands. Plants had clearly spread along the stream – probably from an ornamental pond higher up the hillside – and were heading down through a bog towards the coast (note 5).

American Skunk-cabbage

American Skunk-cabbage spreading, near Oban. 19th May 2018.

Invasion!

The Oban plants illustrate some of the story of Lysichiton americanus in the British Isles.

American Skunk-cabbage was introduced to cultivation here in 1901 and, like many introductions, decided it liked being here. It escaped into the wild in 1947, in Surrey. Since 2000 it has been recorded in roughly 1,000 new sites (an eight-fold rate of increase compared with the previous 40 years). It is now considered invasive and has been banned from sale since 2016. It is now illegal to plant (or otherwise cause to grow) Lysichiton americanus in the wild and gardeners must prevent any Skunk-cabbage growing in their garden from escaping into the wild.

Lysichiton americanus can spread by its rhizomes and by seed. A large seed bank can build up in the soil and can remain viable for around 8-9 years. Unchecked, the plant can eventually dominate large areas, especially in swampy woodland.

American Skunk-cabbage now has its own page on the Scottish Invasive Species Initiative website, where you can report sightings. There is also a PDF file on the GB Non-native Species Secretariat website.

Herbicides are often used to control American Skunk-cabbage but they should only be used by qualified people when the plant is growing near water (as it usually is) because of the harm they can cause to aquatic life. A safer but more labour intensive method is to dig out the rhizomes by hand. You will probably have to wear wellies (or even a full waterproof suit) to do this. Tiny pieces of rhizome can grow into plants but the good news is that the plants only flower when three or more years old. Cutting off flowers will prevent established plants from setting seed.

Mixed Feelings

I have mixed feelings about invasive, non-native plants. They do need to be controlled but it is no accident that they are growing here – they are magnificent. I can understand why they were introduced into gardens in the first place, particularly before we understood they could have a detrimental effect on our native flora.

For me, American Skunk-cabbage occupies a similar place in my heart to other spectacular invasive plants such as the toweringly magnificent Giant Hogweed (Heracleum mantegazzianum). Yes, these plants are invasive, but I love them. (I am less keen on Japanese Knotweed, Reynoutria japonica.)

Fortunately Lysichiton americanus can still be seen in some gardens, including Cambridge University Botanic Garden, where it grows on its own small island in the middle of a pond. Maybe that’s the best compromise, though it doesn’t quite give the thrill of seeing those “wild” plants at Buckenham (note 6).

American Skunk-cabbage, Lysichiton americanus

American Skunk-cabbage, Lysichiton americanus. Buckenham, Norfolk, 5th April 2025

Notes

Note 1 – Skunks are American mammals in the family Mephitidae (related to our Stoat, Weasel, Badger and Otter from the family Mustelidae). They are known for their ability to spray a liquid with a strong, unpleasant scent from their anal glands. Chemically, this is a mixture of sulphur compounds such as thiols , which can smell of garlic, cabbage or rotten eggs. (Thiols are added to natural gas, which is naturally odourless, to allow us to detect its presence.)

In contrast to American Skunk-cabbage, I think the smell of Cuckoo Pint is quite subtle – perhaps “slightly of decay”. It has also been described as “a mixture of mouse, lemon and rotting plant material” to “foul and urinous“. Cuckoo pint flowers attract pollinating Owl Midges rather than rove beetles.

Cuckoo Pint relies on a combination of heat and smell to attract Owl Midges but the spadix of Lysichiton does not heat up to attract insects.

Note 2 – There are two species of Lysichiton worldwide, the other being Lysichiton camtschatcensis, Asian Skunk-cabbage. It has a white spathe and is sometimes known as White Skunk-cabbage, Far Eastern Swamp Lantern or Japanese Swamp Lantern. It grows in northern Japan and on the Kamchatka Peninsula, the Kuril Islands and Sakhalin. Apparently, the flowers are scentless.

Note 3 – There is also an Eastern Skunk-cabbage, Symplocarpus foetidus, another member of the Araceae. Its spathes are mottled with varying amounts of yellowish-green and purple. The spadix emits a strong odour of “fresh cabbage with a slight suggestion of mustard” which attracts blowflies. Spiders often spin their webs at the the entrance to the flowers, to catch the flies.

Note 4 – Later in the year the bright yellow of the Skunk-cabbage was replaced by many other flowers, including the blues of  Himalayan Poppies (Meconopsis) and Gentians (such as Gentiana sino-ornata). Material from the Botanic Garden was extremely useful in Botany practicals. The garden’s Curator, Noel Pritchard, was one of my Botany lecturers and a great plantsman. His knowledge and love of plants inspires me to this day. (He died in 2004 but I’m glad to see there is an annual Noel Pritchard Memorial Lecture in his memory.)

Note 5 – I thought I remembered seeing the yellow flowers of Lysichiton americanus at Oban but of course I was a month too late. Memory plays tricks and my photograph sets the record straight.

Note 6 – The plants at Buckenham are being monitored and I’m told that the population is currently stable.

Cedar Cup, Geopora sumneriana

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Cedar Cup, Geopora sumneriana

Cedar Cups, Geopora sumneriana, in grass beneath a Blue Atlas Cedar tree. Norwich, 9th March 2025.

The quest for Cedar Cups

Last spring I spent quite a lot of time looking for Cedar Cups, Geopora sumneriana. Cedar Cups are usually found beneath Cedar trees (Cedrus sp.) so the search involved visiting churchyards and parks where these grew. I saw some lovely trees, cycled many miles, visited interesting churches and peered over walls into gardens. I looked longingly at majestic Cedars of Lebanon in parkland, tantalisingly out of reach. (Cedar trees are often on private land.) But I found no Cedar Cups.

My search included some known sites but again I found nothing. One, a Deodar Cedar beside Colney Lane in Norwich, had Cedar Cups underneath it in 2015 but the tree died several years ago and is now just a stump. A Blue Atlas Cedar, in the grounds of County Hall, still looked suitable but yielded no fungi.

Cedar Cups at last!

Last Sunday Vanna and I went for a walk through the grounds of our local university and Vanna noticed a fairly small Blue Atlas Cedar. I went across to it and, not expecting any reward, looked in the short grass beneath the tree. Finally, there they were: Cedar Cups, Geopora sumneriana. I found two fruitbodies and Vanna soon found ten more, on slightly sloping ground to the south and west of the tree. The find was completely unexpected and all the more enjoyable for being deferred.

Like other cup fungi, Geopora sumneriana is an ascomycete fungus. Its sexual spores are produced inside elongated sacs known as asci and, when ripe, are forcibly ejected (note 1) .

Cedar Cups develop over several months as underground spheres before breaking through the surface of the soil. As the cup pushes upwards through the soil it forms a small mound of soil and the entrance to the cup looks like the entrance to an insect nest burrow – an extremely large solitary bee or a Minotaur Beetle, perhaps.

A young Cedar Cup, Geopora sumneriana.

A young fruitbody of Cedar Cup, Geopora sumneriana, pushing up to the soil surface.

As it continues to grow the Cedar Cup fruitbody reveals itself. Its inner surface is smooth and pale cream when freshly opened, darkening to a light greyish beige. This is the fertile surface of the fungus fruitbody. The outside of the cup is infertile and covered in curly brown fine hairs, which you can see more clearly if you carefully brush off some of the soil. With its creamy interior and hairy exterior I think a Cedar Cup resembles a tiny, split open coconut.

The cup continues to expand and it can reach five to seven centimetres (two to about two and a half inches) in diameter and up to five centimetres (two inches) tall. Mature fruitbodies usually split into five to seven irregular, star-like rays. The First Nature website has photographs of a couple of mature Cedar Cups and pictures of spores and asci.

We found twelve cups but Cedar Cups can sometimes be found in much larger numbers. The Worcestershire Record website records a remarkable mass fruiting of over 100 fruitbodies scattered on the northern side of a single thirty year old tree. The Wildlife Trusts website has a video presented by the FUNgi Guy, who gave up counting at 170 Cedar Cups (note 2).

Cedar Cup, Geopora sumneriana

Seen from above: Cedar Cup, Geopora sumneriana. Norwich, 9th March 2025.

In Norfolk, Cedar Cup is quite a rare find. It fruits in spring, usually in March or April. Up to the end of 2023 there were 16 records (from 14 sites) in Norfolk, seen between 25th February and 29th April. Just one record was added for 2024, so maybe I didn’t find any Cedar Cups last spring because it was a poor fruiting year. Like many fungi, there seem to be good and bad years. Cedar Cup was seen in exceptionally large numbers during the winter of 2016-17.

The Fungus Records Database of the British Isles (FRDBI) had 221 records when I looked today. Records for Geopora sumneriana mostly come from southern England, though there is a record for Northern Ireland (note 3). Cedar trees grow quite happily further north and we had a Blue Atlas Cedar in our garden near Aberdeen when I was a child, but presumably the conditions don’t suit the fungus.

Distribution map for Geopora sumneriana (16th March 2025).

Distribution map for Geopora sumneriana from The British Mycological Society Fungal Records Database of Britain and Ireland. [Accessed on 16th March 2025]

The Global Biodiversity Information Facility (GBIF) website shows the wider distribution of Geopora sumneriana across Europe (as far north as Denmark) and into Asia. Geopora sumneriana was recorded for the first time from Pakistan in 2018.

Associations

Cedar Cup is, as the name suggests, normally associated with species of Cedar (Cedrus sp.) and the fungus presumably forms a mycorrhizal relationship with the tree. However, Yew (Taxus baccata) is an occasional associate (note 4) and Cedar Cups have also been recorded from beneath a Holm Oak (Quercus ilex) in Kew Gardens.

Geopora sumneriana likes to grow in dry places and Cedars, Yew and Holm Oak all provide these conditions. Well drained soil seems important too and trees with bare soil or short grass underneath them are probably best. (These conditions certainly make it easier to look than under trees surrounded by a bed of nettles.)

Blue Atlas Cedar

A Blue Atlas Cedar, Cedrus atlantica ‘’Glauca’.

Cedars are widely planted non-native trees in the British Isles, particularly in private parkland but also in churchyards and public areas such as parks. There are three species worldwide and all can be found in Britain: Cedar of Lebanon (Cedrus libani), Deodar Cedar (Cedrus deodara) and Atlas Cedar (Cedrus atlantica).

A mature Cedar of Lebanon, Cedrus libani, is instantly recognisable with its characteristic flat layers of branches. Atlas Cedars have clusters of short needles and their branches usually point upwards; a glaucous form (Cedrus atlantica ‘’Glauca’ ) is widely planted. Deodar Cedars has longer, soft needles that droop at the end of the branches. Looking at the branch tips, the mnemonic “ascending = Atlas, level = Lebanon, and drooping = Deodar” is quite useful.

The Cedar of Lebanon has three distinct forms with different geographical ranges and these sometimes treated as separate species:

The Tree Guide UK website has a useful comparison of Cedars, as does the Royal Forestry Society’s species profile.  I often consult pages 90 – 93 of the “Collins Tree Guide” by Owen Johnson and David More (Harper Collins, 2004).

I did a rough count of FRDBI records to see where Cedar Cup records have been found. Most are simply recorded as being associated with “Cedrus sp.” but where the tree has been identified to species, 21 records are with Atlas Cedars, eight records are with Cedar of Lebanon and just one is associated with Deodar Cedar (note 5).

Signs of Digging

When I told my friend James Emerson about the Cedar Cups we’d found he commented “I suspect that sometimes they get eaten by squirrels, as I have looked for them in several other places with previous records and not found them”.

This got me thinking. I’ve often found signs of digging under Cedar trees.

On Wednesday we found more Cedar Cups, this time under a Deodar Cedar in Norwich. There was one fruitbody in the ground and another had been dug up and was lying on top of the soil. There were lots of other holes, presumably made by Grey Squirrels.

Signs of digging under a Cedar.

Signs of digging under a Cedar (with Winter Purslane).

Intrigued, I did an online search.

Geopora sumneriana has some relatives in North America, including Geopora cooperi. G. cooperi is a hypogeous fungus – it spends its time underground and “rarely sees the light of day – leaving squirrels, other rodents, and insects as the primary agents for spore dispersal“.

I also found the study “Diets of Native and Introduced Tree Squirrels in Washington” (note 6), which found that several species of squirrel ate hypogeous fungi throughout all seasons, with spores present in most samples of their faeces. One of the species was the Eastern Grey Squirrel, Sciurus carolinensis, which is an introduced species in Washington and is the Grey Squirrel that has been introduced into Britain.

Geopora sumneriana does pop up above the ground but its fruitbodies spend a lot of time  beneath the soil and perhaps squirrels do like eating them and, in doing so, spread the spores.

The odour of the American Geopora cooperi is described as “not distinctive, or sour and reminiscent of bad apple cider“.

Most descriptions of Geopora sumneriana say it has a smell that is “not distinctive” and I would describe what smell I can detect as soil with something vaguely fungal. However, in parts of Northern India (including Kishtwar National Park) Geopora sumneriana “is frequently consumed by the indigenous people due to its rich aroma, abundance and flavour“. Maybe squirrels also detect a “rich aroma” and good flavour?

In Britain, Geopora sumneriana is thought to be poisonous when raw and possibly even when cooked. Even if it tasted delicious, it wouldn’t be a good idea to harvest such a comparatively rare fungus and “in any case the flesh is insubstantial“.

Other UK Geopora

The 1996 paper by Yao and Spooner, “Notes on British Species of Geopora” (Mycol. Res. Vol. 100, pp72 – 74) is available as a PDF online and lists several other British species. Two of these, Geopora arenicola and Geopora cervina, are rather rare but have been found in West Norfolk. They tend to grow in places with sandy soil but aren’t associated with Cedars. I haven’t seen either of them.

Geopora means means “earth cup”. Synonyms for Geopora sumneriana include Sepultaria sumneri and Sepultaria sumneriana. Sepultaria means “underground tomb”. Both names are appropriate for this hypogeous or partially hypogeous genus of fungi.

In Welsh, Cedar Cup is Cwpan Cedrwydd.

The specific name of Cedar Cup, sumneriana, is named after the American ichthyologist, zoologist and writer Francis Bertody Sumner (1874 – 1945).

Cedar Cup, Geopora sumneriana

A single Cedar Cup, Geopora sumneriana, with Common Field Speedwell and Daisy for scale.

Notes

Note 1 – Ascomycetes are known as “spore shooters”. Once the spores are mature the ascus bursts open (usually at the top) and spores are released. Wind currents frequently disperse the spores but sometimes animals can move them on their feet (as in Olive Salver, Catinella olivacea, which I wrote about in December 2022). Some species can forcibly eject their ascospores for distances of up to 30 cm (12 inches).

I’ve written about several other ascomycete fungi on this blog, including the cup fungi Spring Hazelcup, Encoelia furfuracea,  Scarlet and Ruby Elfcups (Sarcoscypha sp.) and Alder Goblet (Ciboria caucus).

The singular of asci is ascus, from the Greek askós, meaning sac or wineskin.

Note 2 – The FUNgi Guy cried “Yabba Dabba Doo” when he found them; I did something similar, though internally.

Note 3 – A login is required to access the FRDBI database. Membership of the British Mycological Society gives this access, which is well worth considering if you have more than a casual interest in fungi.

The distribution map is from the FRDBI (made available under a Creative Commons BY-NC-SA Attribution – Non Commercial – Share Alike licence).

The NBN Atlas website shows the British distribution too.

Note 4 – At the time of writing there is one record for Cedar Cups growing with Yew on FRDBI. Last summer I visited a house near the centre of Norwich where Cedar Cups have been found under a Cedar tree and also with Yews at the far side of the garden, probably beyond the range of the Cedar’s roots.

Note 5 – I know of at least two Norfolk records of Cedar Cups associated with Deodar Cedar. One was recorded as “Cedrus sp. and the other is very recent so hasn’t yet reached FRDBI.

Incidentally, the Cedars I’m writing about are “true cedars”. Trees like Western Red Cedar (Thuja plicata) are conifers too, but are not closely related.

Note 6 – Aaron N. Johnston, Stephen D. West, and W. Matthew Vander Haegen (2019). “Diets of Native and Introduced Tree Squirrels in Washington”. The Journal of Wildlife Management Vol 83(7), pp1598–1606.

Spores from fungi – species of Rhizopogon (false truffles), Geopora, and Melanogaster spp. – were found in most faecal pellets.

Cinnamon Bracket, Hapalopilus nidulans

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I like distinctive, easy to identify fungi. One of these is the Cinnamon Bracket, Hapalopilus nidulans. 

(Cinnamon Bracket is also known by its synonym, Hapalopilus rutilans, but I am using Hapalopilus nidulans because it is the name currently being used by the British Mycological Society.)

Cinnamon Bracket, Hapalopilus rutilans

Cinnamon Bracket, Hapalopilus nidulans, on a decaying Hazel branch.  January 2025.

“An easily overlooked, unexciting fungus”

You might not think Cinnamon Bracket was distinctive, as it isn’t one of our larger, more impressive species of fungi.

Cinnamon Bracket has a small, fan-shaped to semicircular annual fruitbody no more than 2 – 12 cm (0.8 – 4.7 inches) in diameter, which attaches without a stalk to its substrate, a small log or stick.

Hapalopilus nidulans has an ochraceous to cinnamon brown top that becomes pinkish brown with age, while on the underside the thin-walled angular pores (2 – 4 per millimetre) are the same colour as the top.

To some Cinnamon Bracket is “an easily overlooked, unexciting fungus” but to those of us who appreciate nature’s subtleties it “stops you in your tracks during a woodland walk. Its warm, cinnamon-brown colour and soft, velvety texture make it stand out against the dull greys and greens of decaying wood“.

There is usually a distinct sterile margin around the pores, as in the photograph below.

Underside of Cinnamon Bracket, Hapalopilus rutilans, showing pores.

The underside of a Cinnamon Bracket, Hapalopilus nidulans, showing the pores and sterile margin. October 2022.

Cinnamon Bracket causes a white rot, breaking down lignin, cellulose and hemicellulose. In Europe it usually grows on hardwood species. In Northern Europe the main hosts are Hazel (Corylus avellana) and Sorbus (such as Rowan, Sorbus aucuparia), while in Central europe oaks (Quercus) are the commonest host trees. Hazel is the commonest host in the British Isles.

Hapalopilus nidulans is widespread in Europe as far north as Norway and also occurs in North Africa, Asia, North America and on mountains in tropical Africa (note 1). It has also been recorded from Australia and Oceania. Unusually, it is usually found on conifer debris in south-western parts of North America.

Underside of Cinnamon Bracket, Hapalopilus rutilans.

Underside of Cinnamon Bracket, Hapalopilus nidulans, showing pores. this specimen only has a small sterile margin.

I’ve seen Hapalopilus nidulans twice. There are 61 Norfolk record of Hapalopilus nidulans up to the end of 2024, from August to February, and most of these have been on Sorbus, Corylus, Quercus and Betula (birches). At the time of writing, there are 599 records on the NBN Atlas, mainly in England the northern half of Scotland.

Just add KOH

So far, fairly unexciting. But what makes Hapalopilus nidulans really distinctive is the chemical reaction when a drop of an alkaline solution, such as ammonia or potassium hydroxide (KOH), is added to its surface.

Where the alkali meets the fruitbody there is an instant colour change from pinkish brown to vibrant purple. Cinnamon Bracket is transformed from a small, subtle fungus into something truly memorable.

Jan Thornhill’s Weird and Wonderful Wild Mushrooms blog captures the excitement of the colour change: “When this otherwise boring fungus comes into contact with either ammonia or KOH, it immediately turns a psychedelic fuchsia (or cherry red in other parts of the world), a reaction that’s so magical and so spectacular it’s hard not to play with the effect over and over again” (note 2).

Underside of Cinnamon Bracket, Hapalopilus rutilans.

The underside of a Cinnamon Bracket, Hapalopilus nidulans, goes purple when treated with potassium hydroxide solution.

Polyporic Acid

Hapalopilus nidulans contains large quantities of polyporic acid (from 20 to 40% by weight) and it is this which reacts with an alkali to give the purple colour (note 3). 

Most polypore mushrooms are non-toxic and some (such as Chicken of the Woods) are edible and delicious but please don’t eat Cinnamon Bracket, as polyporic acid is toxic to mammals, including humans.

Polyporic acid (2,5-dihydroxy-3,6-diphenylcyclohexa-2,5-diene-1,4-dione) messes up RNA synthesis, specifically the manufacture of uracil, one of the nucleotide bases that form RNA. It does this by inhibiting the enzyme dihydroorotate dehydrogenase, which catalyses the synthesis of orotic acid, which is used to make uracil.

Polyporic acid damages the nervous system, liver and kidneys and eating a Cinnamon Bracket will lead to gastrointestinal distress, blurry vision, inability to balance, loss of kidney function, and purple urine. (The latter would be an impressive party trick but please don’t try this at home!)

The symptoms of poisoning begin about twelve hours after ingestion and can persist for a few days, but usually clear up within a week (note 4).

Polyporic acid also has anti-fungal and anti-bacterial properties and is found in several other species of fungi. Some of these are only distant relatives and the ability to produce polyporic acid is thought to have arisen independently three or four times.

Purple Dye

A safer and more practical use of Cinnamon Bracket is as a source of a lovely purple dye.

Thomas Roehl says (on the Fungus Fact Friday website) that Hapalopilus nidulans works very well as a dye for wool:

“To use this mushroom for dyeing, break it up into small pieces and place it in hot water with pre-mordanted wool. Then use ammonia to adjust the pH up to 9. The ammonia turns the mushroom purple. That color leaves the mushroom and adheres to the wool, turning it anywhere from a deep purple to a bright lavender. You normally use a 1:1 dry weight ratio of mushroom to wool, but H. nidulans is a strong dyer and you can probably use less. This is good, since H. nidulans is a fairly uncommon mushroom.”

Ann on the Shroomworks website (“Hapalopilus, Ever Abundant“, June 2018) gives more practical advice for dyeing with Hapalopilus nidulans and shares the results, some beautifully coloured balls of wool. She confirms that a small amount of the fungus goes a long way and has used a 150 gramme (5.2 oz) sample from Sweden about thirty times.

Jenny Dean also writes about dyeing with Hapalopilus nidulans (“South Downs Yarn & colours from fungi“) and the North American Mycological Association website gives details of this and other fungi that can be used for dyeing (“A Short Selection of the Best Mushrooms for Color“). This article also mentions Inonotus hispidus (Shaggy Bracket), which I wrote about a few months ago, not realising it could be used for dyeing.

I found my second Cinnamon Bracket a month ago in woodland to the west of Norwich while on a bike ride with my wife Vanna. I was pretty sure what it was but hadn’t taken my bottle of KOH out on my bike ride, so I took it home to check (note 5).

I’ve dried the bracket and passed it to my friend Sarah, who dyes fabrics. I hope to see the results soon and, if the dyeing is successful, I’ll share the results.

Other Names for Cinnamon Bracket

In Welsh, Cinnamon Bracket is Ysgwydd Sinamwn. Other English names for Hapalopilus nidulans (used in the United States) include Purple Dye Polypore and Tender Nesting Polypore. The specific name nidulans means “nesting”; rutilans is “orange-red” in Latin. Hapalopilus is from Ancient Greek, meaning “tender cap”.

Possible Confusion: Beefsteak Fungus

I think Cinnamon Bracket is pretty distinctive, even without the help of KOH, but a novice might possibly think that Hapalopilus nidulans was a very small Beefsteak Fungus (Fistulina hepatica) and indeed a 2013 poisoning by Hapalopilus nidulans occurred when someone mistook a Cinnamon Bracket for a Beefsteak Fungus.

Unlike a Beefsteak Fungus, Cinnamon Bracket never “bleeds” or reaches the size of a mature Beefsteak. The pores of Fistulina hepatica are straw-yellow, becoming reddish-brown as the fruiting body ages and unlike Hapalopilus rutilans they bruise deep red-brown. Fistulina hepatica is mainly found on oaks and Sweet Chestnut (Castanea sativa) in late summer and autumn, from August to October.

Beefsteak Fungus, Fistulina hepatica

Beefsteak Fungus, Fistulina hepatica. This one is “bleeding” slightly.

Unlike Cinnamon Bracket, the Beefsteak Fungus is edible, though mainly for the novelty of eating a fungus that looks like raw meat or liver. It can be consumed raw or cooked. I cooked it once and found it pleasant enough and would eat it again, though it was a bit acidic and lacked the balance of flavours that makes Chicken of the Woods so enjoyable. I agree with the First Nature website: “as an edible species it does not really live up to its good looks” (note 6).

Beefsteak Fungus, Fistulina hepatica

Beefsteak Fungus, Fistulina hepatica. “Edible, though mainly for the novelty of eating a fungus that looks like raw meat or liver”.

Top surface of Cinnamon Bracket, Hapalopilus rutilans

In contrast to a Beefsteak Fungus: The top surface of Cinnamon Bracket, Hapalopilus nidulans.

Notes

Note 1 – In “Poroid Fungi of Europe” Ryvarden and Melo use the name Hapalopilus rutilans.

They list its hardwood hosts as Acer, Aesculus, Alnus, Betula, Carpinus, Corylus, Crataegus, Fagus, Ficus, Fraxinus, Malus, Pittosporum, Populus, Prunus, Quercus, Robinia, Sambucus, Salix, Sorbus and Tilia. It occasionally grows on conifers such as Abies, Picea and Pinus. Pages 182 – 183, L. Ryvarden & I. Melo (2022). ‘Poroid Fungi of Europe’. 3rd edition. Fungiflora, Oslo, Norway.

Note 2 – In “Poroid Fungi of Europe” Ryvarden and Melo give the colour with KOH as “a vivid violet”. This is what I’ve found when I’ve treated specimens with KOH, as shown in my photograph above.

However, Michael W. Beug (in “Polyporic Acid in Fungi: A Brief Note“) says that “Ko, Jung and Ryvarden (2001) give the reaction between Hapalopilus nidulans and KOH as strongly cherry red, though North American collections give a lilac to violet reaction”. (See Ko, K.S., H.S. Jung and Lief Ryvarden (2001). “Phylogenetic relationships of Hapalopilus and related genera inferred from mitochondrial and small subunit ribosomal DNA sequences.” Mycologia Vol 93(2): pp 270 – 276.)

Note 3 – Michael W. Beug (in “Polyporic Acid in Fungi: A Brief Note“) speculates that the colour change “is the result of an acid-base reaction and that any base would produce the color change by removing an acidic proton” and this is the best explanation I have found. Please let me know if you find more details of this chemical reaction.

Not all colour changes with KOH are caused by polyporic acid. For example, the Hoof Fungus (Fomes fomentarius) goes dark blood red when a drop of KOH is added to a piece of tissue from the upper surface but this is due to the presence of fomentariol, a benzotropolone. (Arpin, N., J. Favre-Bonvin, W. Steglich  (1974): “Fomentarol: A New Benzo Tropolone Isolated From Fomes fomentarius“. Phytochemistry Vol. 13 (9), pp1949 – 1952).

The paper “Pigments of Higher Fungi: A Review” is worth a read if you want to know more about the many pigments that occur in the colourful kingdom of fungi.  J. Velisek & K. Cejpek (2011), Czech Journal of Food Sciences Vol. 29(2), pp87 – 102.

Note 4 – On the Weird and Wonderful Mushrooms website Jan Thornhill gives more details of Hapalopilus nidulans poisoning:

“The few cases of poisonings on record, including one adult and two children in the late Eighties, and a father and daughter a couple of years ago, (the latter incident involving the consumption of H. nidulans after misidentifying it as the “beefsteak fungus,” Fistulina hepatica), have all been similar in their descriptions of signs and symptoms that happen after a delay of at least 12 hours, the results of dysregulation of central nervous system functions and liver and kidney dysfunction:

  • abdominal pain
  • nausea and vomiting
  • headache
  • visual disturbances, including double vision, blurred vision, hallucinations
  • multidirectional involuntary eye movements
  • balance disorders 
  • general weakness
  • loss of appetite
  • signs of liver and kidney failure
  • and violet-coloured urine“.

The Jungle Dragon website mentions two poisoning cases – presumably the same ones – reported in 1992 (a family of three in Germany) and 2013. In both cases the symptoms started about 12 hours after ingestion and consisted of nausea, impaired movement, visual impairment, liver and kidney failure. The patients’ urine was purple. Everyone involved had recovered fully a week later.

Note 5 – We found a few other fungi here, including Spring Hazelcup (Encoelia furfuracea), Alder Scalycap (Pholiota alnicola) and Blushing Bracket (Daedaleopsis confragosa).

I would ideally have tested the bracket with KOH in the field, leaving it as a habitat for small invertebrates such as beetles.

Note 6 – Most wild fungi should be cooked before eating. Beefsteak Fungus is one of the few that is safe to eat when raw. Chicken of the Woods, in contrast, must be cooked and you should it eat with caution the first time you try it, as it can cause gastric upsets in some people.