Fungi in Coldfall Wood

Black Bulgar (Bulgaria inquinans), not King Arthur’s Cakes!

Updated – several keen-eyed readers have advised that the black fungi in the photos are Black Bulgar (Bulgaria inquinans) not King Alfred’s Cakes – they’re flatter, and look more like buttons. It’s been noted that they look like liquorice, but are definitely inedible. They’re frequently found on fallen oak trees, as this one was. We didn’t see any King Alfred’s Cakes on this trip, but they are pretty common so I’ve included an account anyway!

Dear Readers, I was in Coldfall Wood on Wednesday with my friend S and Alastair from The Conservation Volunteers. We were looking at the condition of the woodland, but it was impossible to ignore the sheer variety of fungi that seemed to be popping up everywhere. There’s a lot of dead wood, which is the perfect habitat for all kinds of creatures, and which is steadily broken down by the fungi (all the more reason for leaving it alone and not using it to build dens which seems to be a popular occupation).

These are King Alfred’s Cakes (Daldinia concentrica) Photo by Walter Baxter

First up is this coal-black fungi known as King Alfred’s Cakes or Cramp Balls. They’re named after the legend of King Alfred, a 9th century king of England, taking refuge with a peasant woman, who asked him to keep an eye on the cakes she was baking. Alas, being a bloke his mind was on other things and the cakes burned to a crisp. Interestingly, the fungus has also been used as kindling to start fires, with evidence from a 7,000 year-old Spanish settlement showing that this practice has been around since at least the Stone Age.

King Alfred’s Cakes also seems to form a natural home for over 100 different species of invertebrate and the caterpillars of one moth, the Concealer moth (Harpella forficella) are known to feed on it (which I guess makes them fungivores). They have particularly splendid antennae.

Concealer moth (Harpella forficella) Photo by By Adam Furlepa – Own work, CC BY-SA 3.0,

The photos below are  of Black Bulgar – I was very taken by how splendid the fungi looked, dotted all over a fallen branch – the individual fungi look like black leather buttons to me.

Black Bulgar – Photo by Alastair McKinlay

Black Bulgar – Photo by Alastair McKinlay

Black Bulgar – Photo by Alastair McKinlay

Then there was this fungus, found growing around the base of a living oak tree. This is Spindleshank (Gymnopus fusipes).

This fungus is also known as ‘Toughshanks’, because the central ‘stem’ can  become bloated, and the whole fungus is thought to be stringy and inedible. Which is a shame, because there’s a lot of it about. It is usually associated with the roots of beech or oak trees, and is parasitic, though the tree that it was attached to seemed pretty healthy to me, at least at the moment. A healthy plant or animal can shake off a moderate parasite load, it’s when the organism is sickly that many fungi start to take advantage.

Spindleshank (Photo by Alastair McKinlay)

And then there was this fungus, spotted growing towards the top of a dead silver birch stump. There is precious little silver birch in Coldfall Wood, it being mainly a hornbeam and oak wood, but there were four in this spot, planted in the shape of a rectangle. What was going on,  I wonder? Anyhow, this is Birch Polypore, or Razorstrop Fungus (Piptoporus betulinus).

Photo by Alastair McKinlay

Here’s a photo showing Birch Polypore fungus from above (none  of us were up to shinning up the tree, which is probably just as well).

Photo by Walter Baxter / Birch Polypore (Piptoporus betulinus)

This fungus was actually used to sharpen knives, having a tough, leathery exterior, hence the name ‘Razorstrop’. Incidentally, I wondered if the word ‘strop’ was the origin of ‘stroppy’, but apparently not: ‘strop’ comes from the Latin word ‘stroppus’. This was a  piece of leather that could be used in a harness, or to attach an oar, but which came eventually to mean a piece of leather used to sharpen a knife or cutthroat razor (think Sweeney Todd here). ‘Stroppy’ as in ‘teenager’ comes from obstreperous, apparently, also from the Latin words meaning ‘to make a noise’.

But I digress, as usual. Apparently wood that is decayed by the fungus apparently smells distinctly of green apples, though we didn’t notice it in this case. It will completely break down the timber of the birch, but it can lie dormant for decades in a healthy tree, only appearing if the tree is weakened. Birch polypore is eaten by the caterpillars of another moth (the creatively named Fungus Moth (Nemaxera betulinella)), shown below in an illustration from British Entomology by John Curtis (1843)

And finally, how about this sweet little fungus? I rather think that it’s an Amethyst Deceiver (Laccaria amethystina) though clearly it’s only a baby.

Photo by Alastair McKinlay

This is one of my favourite fungi, mainly because purple is one of my favourite colours (I also confess to a penchant for turquoise and teal), but also because although common it often goes unnoticed – the fungus turns from delicate lilac to brown very quickly as it matures. Although it’s considered to be edible, it picks up arsenic from the soil and concentrates it, so you might not want to snack on one. Recent research has also shown that it’s an ‘ammonia fungus’ – i.e. it grows where there is a high concentration of ammonia in the soil. I am inclined to wonder if the large number of dogs in the wood is contributing to this – post lockdown there are endless dog walkers with positive packs of canines, all marking their territory. I don’t think that a fungal survey of the wood has ever been done, but it would be very interesting to see if there has been a general uptick in this kind of fungus since the pandemic.

Whatever the causes, this is a lovely fungus to finish on, and makes me feel very happy that I’m retired (did I mention that I’m retired?) and that I have the time to really appreciate the pleasures of a walk in the wood in autumn. If you have a chance, go and see what you can see – I feel as if this might have been a very good year for fungi generally. Let me know if you see anything interesting!

Amethyst Deceiver – Photo by By GaryGMason – Photographed 20151027, CC BY-SA 3.0,


5 thoughts on “Fungi in Coldfall Wood

  1. Daniel Greenwood

    Have you looked at black bulgar for the first ones rather than King Alfred’s cakes? Lovely to see all this. Very similar to what pops up on oak woodland south of the river.


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