Fingal's Mushroom

Content warning: I make a lot of wrong assumptions about the identity of the mushroom in this blog, before I eventually come to a conclusion I have a reasonable amount of confidence in.

 

The main reason we were on the Isle of Iona (see previous post  about its waxcaps) was to take a trip to Staffa.

View of Staffa as the boat approaches from Iona.

The boat trip from Iona gives you one hour to explore the island which rises out of the North Atlantic Ocean like a giant basalt cathedral. One hour.

While our shipmates formed an orderly queue to see Fingal's Cave, we raced up the steps to explore the island. Surrounded by a dramatic, rocky coastline, Staffa has a grassy, heathy cap which I figured MUST have some mushrooms on it. 

At the side of an inauspicous-looking path, I spotted one small patch of waxcaps...

... hiding in the long grass.

Bright sunshine illuminated the scales on the cap of this little red mushroom. 

Underneath, pale yellow (adnate / adnexed?) gills, which looked almost white in the sunshine, contrasted with the red cap and smooth stipe. 

There was no time for closer observation in the field. We had to leg it back down to sea level or we'd miss our chance to see Fingal's Cave and the boat back to Iona. 

Fingal's Cave was amazing and impossible to photograph in five minutes with a phone, and the light outside blazing...

Returning to the boat we noticed the reddish-brown jellyfish hanging in the water, close to where it laps against these basalt columns. But there was no time to stand and stare, or get a better snap.

Back on the boat, I remembered the mushrooms I'd hurriedly thrust into my pocket earlier on. 

One specimen looked to have dark grey scales at the centre of the cap. 

Being in my pocket hadn't done them any good, but I could still make out this specimen has adnate gills. 

Hoping no one was watching, I gave them a good sniff. Nothing. 

I thought they were probably Hygrocybe miniata and, reading back through the descriptions in Boertmann's book (The Genus Hygrocybe, 2nd Edition), they are described as having "squamules concolorous and becoming yellow after slight drying, very rarely dark greyish in the centre" - which sounded about right. That species has distinctively pear-shaped ('mitriform') spores so I thought I'd take a look to confirm.

I'm still struggling with preparing microscope slides with dried material - and these were particularly squashed and broken by the time I got them home - so I tried a new approach: putting a drop of ammonia on a slide and just washing a couple of gills in it, to see if some spores would float off. It worked!

The following images are all captured at 400x magnification.

I found plenty of spores floating around. But none of them look mitriform to me. So I think that rules out H. miniata.

Hmm. 

I started again from the beginning with Boertmann's key, and found myself getting into some seriously tricky territory - these little red waxcaps can be rather cryptic. 

Could I have found Hygrocybe calciphila? Spore shape appears to be a better match. Boertmann says it's "generally rare, but may be overlooked" and describes it as known to occur on "basic (basalt or gypsum) soils"; I think it's probably a safe bet that the soil on Staffa is basalt-y!

Hygrocybe calciphila seems like the best fit with everything I've observed. But given it's so rarely recorded (and a new species to me) it would be good to get it confirmed by someone who knows what they're doing. Or perhaps an ITS barcode... 

Update 24/09/2022

I got an email from Andy McLay, Natural England's waxcap expert, advising me to compare my collection with Garlic Waxcap Hygrocybe helobia.  I think I ruled this out because I didn't get the faint smell of garlic ... but that was really an oversight on my part. 

Hygrocybe helobia is fairly distinct in its microscopic characteristics, having a regular gill trama with long, slender elements. 

I should get in the habit of checking gill trama characteristics - looking at a cross-section of the gills in thin-section - but the truth is I'm not very good at preparing the thin-sections so I avoid doing it. 

I am reasonably confident, having spent quite-a-long-time looking at some squashes from my collection under the microscope, it has a regular gill trama. 

Gill trama, from dried material. 400x magnification mounted in ammonia and stained with Congo Red.

So I think there is good evidence here for going with Andy McLay's suggestion that what I've got here is Hygrocybe helobia. That would fit with the spore shape being rather variable. Another feature of H. helobia that Boertmann mentions in his description is that the flesh is very fragile - that's something I observed as my collection broke into pieces almost as soon as I touched it.

Thanks Andy! 

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Couldn't resist one more try at getting a decent gill trama squash. I think this one's better:

100x magnification. Gill cross-section mounted in water and stained (carefully!) with Congo Red.

Same as above, at 400x magnification. I am confident I can see long slender elements here, with tapering ends.

 

For the record

Date: 5 September 2022

Location: Staffa

Record will be entered into iRecord in due course, if I get a decent fix on what species it is!

Mushrooms on the Isle of Iona

I've been on my holidays to the Isle of Iona, off the west coast of Scotland. We had three nights there in a shepherd's hut ('the bothy'). What a beautiful little island it is!

Iona is famous for its Nunnery and the Abbey, founded in 563, where scribes illuminated the ancient Book of Kells (probably).

[The following image from the Book of Kells might take a minute to load ...]

 

Are those mushrooms I see gracing its pages?!

 

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Thinking that three days there would afford me some time to explore the island, I did a bit of research before I went, to try and suss out what I might expect to find...

 

A search on the NBN Atlas turned up zero records of non-lichenised fungi on the island.   

I contacted Argyll Biological Record Centre who said: "We don't have any non-lichen fungi records from Iona at present, but would be very pleased to receive some!"

A search on the new FRDBI brought up fungus records for Fairy Ring Champignon Marasmius oreades, a mildew Plasmospora densa, a rust on Daisy Puccinia obscura and an obscure ascomycete that grows on Juniper Mytilinidion acicola. 

So it seemed that the Isle of Iona would be largely uncharted territory, as far as fungus recording goes. How strange that on this holy isle, which has been a place of pilgrimage for centuries, where visitors are invited to enjoy the "inspiring landscape and wildlife", scarcely a soul has taken any notice of the fungi. Or so the available evidence would suggest ...

 

In the visitor centre, a hessian display board draws attention to "Flowers of the Machair" [the sandy shore along the western seaboard] and there is a choice of two guides to the wildflowers of Iona in the shop. But nary a mention of mushrooms.

Maybe there just aren't any good mushrooms on Iona? We took a walk to the Machair to find out. 

A' Mhachair, Isle of Iona, Scotland

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Collection #7

It didn't take long to find these little stunners. Conical orange-red caps and yellow stipes.

Collection #7

 

Similar-looking mushrooms were popping up at various points across the Machair. 

 

Collection #3

 

One thing these reddish specimens had in common is that they showed some signs of blackening; but they weren't quickly or strongly blackening like other waxcaps I've come across (e.g. here).
 

Collection #4

They have the appearance of Blackening Waxcap Hygrocybe conica s.l. but there is another species described by P.D. Orton which occurs in sand dunes and coastal habitats: H. conicoides which has the characteristic of not turning black as readily as H. conica, and in dried specimens the gills usually keep the original colour (as my collections have). I think that may be what I have here.

 

According to Boertmann's descriptions (The Genus Hygrocybe, 2nd Edition), H. conicoides tends to have longer, narrower spores than H. conica. 

 

After a frustrating attempt at trying to measure spores from a gill squash, I thought I'd try finding some mature spores on a tiny strip of the surface of the stipe - a new technique for me. It worked!

Collection #7. Image of spores resting on a fragment of the stipe surface. 40x magnification mounted in water.

With an average Q value of 2.0, the spores do appear to be quite long and narrow. So I think perhaps I can call this collection Hygrocybe conicoides, or Hygrocybe conica var. conicoides (P.D. Orton) Boertm. It's not a species I've had any experience with before. 

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Perhaps even more frequent across the Machair were these lemon yellow waxcaps. The slightly conical caps and non-blackening flesh suggests Persistent Waxcap Hygrocybe acutoconica. The young fruit bodies were noticeably moist, particularly on the stipe where they weren't exposed to the sea wind.

 

Collection #5

Another, smaller, collection showed the characteristic of weathering to a light grey colour (and not blackening). 

 

Collection #1

I had a look at the spores from collection #5 and they are a good match for Hygrocybe acutoconica var. acutoconica - mostly oblong shaped.

 

Collection #5. Here you can just see a few spores resting on the stipe surface. 40x magnification mounted in water.

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Also in the Machair, this small orange-red waxcap was something different. Note the slightly scaly ('squamulose') appearance to the cap and the compressed stem. This collection looked like Honey Waxcap Hygrocybe reidii to me, but I wasn't able to detect a honey scent.

Collection #2.

A quick look at the spores rules out the similar-looking (and much rarer) Hygrocybe constrictospora, I think. 

Collection #2. Spores on the stipe surface. 40x magnification mounted in water with Melzer's iodine.

Working with tiny dried-out specimens, which spent two days on a shelf in a humid shepherds hut before I managed to find a radiator to properly dry them out on, is testing my microscopy skills somewhat (!) but I think I got a reasonable look at the shape of the spores here, and they don't look constricted to me.The size also looks about right for H. reidii, so I guess I'll go with that identification. 

Collection #2.

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At the northern edge of the Machair, near Port Ban Beach, the coastal grassland transitions to heathy grassland and then moorland: a more acid habitat. 

On a grassy bank, we found a patch of glistening yellow mushrooms. The viscid cap, smooth stem and adnexed gills took me to Golden Waxcap Hygrocybe chlorophana. I believe typical fresh specimens of this species are confidently identifiable in the field. 

Collection #10

After tramping through the moorland along Iona's north-west coast, we reached some grazing pastures near our campsite. In one of the fields we found another waxcap - a little the worse for wear after some heavy rainstorms. 

 

Sadly this collection went putrid before I was able to dry it, so ended up in the bin. But I'm thinking it's most likely a reddish-orange form of Persistent Waxcap Hygrocybe acutoconica. 

Back at the campsite, in the rocky grassland near our shepherds hut, a final waxcap. With its dry, apricot-coloured cap and decurrent gills, it's the unmistakeable Meadow Waxcap Cuphophyllus pratensis.

I think that makes at least five species of waxcap on the Isle of Iona, from a couple of hours of looking. 

 

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So there ARE good mushrooms on Iona, just waiting to be recorded. Not only waxcaps! I saw some nice fungi on dung too, although I'm less confident on identifying those.

 

 

Psilocybe coprophila?

 

Egghead Mottlegill Panaeolus semiovatus?

Have you seen some fungi on the Isle of Iona? You can capture observations on iNaturalist, even if you don't know what it was. Or you can record species observations on iRecord or the FRDBI.

If you like the sound of the shepherd's hut on Iona, I should warn you it's a few minutes walk to the bathroom. But there's a chance you might see a toad on the way there. 

For the record

Date: 4 September 2022

Location: Isle of Iona, Scotland

Records will be entered into iRecord in due course.