Unknown Pluteus

[Leif]

I am sure most of you would have narrowed this one down to a Pluteus:



Collection notes:

"Berkshire, 22 May 1997, on rotten Beech, cap bright yellow with brown areas, diameter about 6cm. Gills pale pink. Stem twisted, white. Margin lined, cap silky. Spore print deep salmon pink. Spores smooth sub-spherical 6x5 um2."

I do not think it is Pluteus luteovirens, which is fairly common in the south, partly due to the large size, but also the jizz is not right. The silky cap and brown markings do not fit.

It ticks most of the boxes for Pluteus leoninus (size, silky cap, whitish stem, pale pink gills, spores in the right ball park), but what about the distinctive brownish regions on the cap, especially at the centre? From photos I have seen, the texture of the cap especially at the centre is correct i.e. sort of granular. The BFF Volume 4 mentions buff stippling especially at the centre. But I hesitate to assign it to Pluteus leoninus, which I am not familiar with.

Unfortunately the impression I have from the literature is that I will get nowhere without microscopic examination, especially of the cap cuticle. Unless someone is very familiar with the species in question ...

Comments welcome.

[big bill]

Hello Leif not much good at this but like to try and improve my knowledge on checking the books the only near match that I got was the Lion Shield (Pluteus leoninus) the image in the book does show a slight brown colouring to the central part of the cap,but I am only making a observation from the book and stand to be enlightened best of luck on this

[Alantb]

Pluteus have free gills, which you don't mention, and the gills are mainly quite close - these look a bit distant. Pluteus leoninus is a sort of golden yellow colour on the cap and has a less chunky jizz IMHO. Also, if a Pluteus it should have had spiky, grappling-iron cystidia. Are you sure about the spore shape, because this looks a bit like an Entoloma to me?
Alan

[Leif]

It is definitely a Pluteus, but there are a few similar species, some quite rare. Pluteus leoninus is uncommon.

Entoloma have angled/faceted spores.

[FungiJohn]

It's definately Pluteus and looks to me like Pluteus chrysophaeus. What ever it does turn out to be ... it's a cracking image.

[Alantb]

Yes it is a great picture, but it doesn't look much like the P. chrysophaeus for instance on continental websites like this:-
http://www.amo-nantes.com/Files/plut...sophaeus_1.jpg
There are more pics allegedly of chrysophaeus on a Danish site and these look more like P. leoninus and could be mistaken for it but still not much like the picture. I've seen chrysophaeus and made that mistake .... it looks smaller and more fragile than the pic.

[FungiJohn]

I must admit Alan it doesn't look like any Pluteus chrysophaeus I have found either. It does tend to steer the thought to something else btw it does look very dry!

[Leif]

Pluteus chrysophaeus is the current name for Pluteus luteovirens, which I know well, and see often.

[Leif]

Originally Posted by Alantb

Yes it is a great picture, but it doesn't look much like the P. chrysophaeus for instance on continental websites like this:-
http://www.amo-nantes.com/Files/plut...sophaeus_1.jpg
There are more pics allegedly of chrysophaeus on a Danish site and these look more like P. leoninus and could be mistaken for it but still not much like the picture. I've seen chrysophaeus and made that mistake .... it looks smaller and more fragile than the pic.

That aint no P. chrysophaeus! It looks not unlike Pluteus phlebophorus, but I would not like to be more definite on the basis of the photo. According to British Fungus Flora V4, Pluteus luteovirens is "lemon-yellow or greenish-yellow".

Yes P. chrysophaeus is much more fragile, and the cap shape is wrong. Also those brown granules on the cap are wrong.

[Fungus Ken]

Originally Posted by Alantb

Also, if a Pluteus it should have had spiky, grappling-iron cystidia.

Only one group has these distinctive cystidia and this one, which is a Pluteus, does not fall into that group, based on its overall jizz.

Originally Posted by Alantb

Pluteus leoninus is a sort of golden yellow colour on the cap and has a less chunky jizz IMHO.

According to Flora Agaricina Neerlandica Volume 2, Pluteus leoninus can have a cap up to 10 cm wide, although the typical size would be 3-6 cm. Also the cap colour can be yellow to yellow-brown, with a concolorous or slightly darker centre, drying paler to pale yellow-brown.

With the distinctive colour and size of these specimens I think Pluteus leoninus is a strong possibility. I think the jizz is wrong for Pluteus chrysophaeus, which tends also to be quite a small species.

But with Pluteus it does all come down the microscopy and you could be in totally the wrong section if you haven't checked the cap cuticle and the cystidia.

Ken

[Fungus Ken]

Originally Posted by Leif

It looks not unlike Pluteus phlebophorus, but I would not like to be more definite on the basis of the photo.

As far as I am aware, Pluteus phleboporus would not have any yellow tones in the cap. I found this species last year and the specimens I found were a dark brown colour when moist and they had a wrinkled-veined appearance.

Originally Posted by Leif

According to British Fungus Flora V4, Pluteus luteovirens is "lemon-yellow or greenish-yellow".

Pluteus chrysophaeus now includes a number of taxa that were formerly considered as separate species, including P. luteovirens, as you say. But the cap colour can vary from olive-yellow to yellowish-brown, so I don't think you could rule it out on cap colour alone. Also the cap can be venose to rugulose in the centre. However, in my experience, P. chrysophaeus tends to be a smaller species than the specimens you have described.

But without microscopy I couldn't say anything with certainty.

Ken

[Fungus Ken]

PS The spores seem rather small. According to FAN2, it would be just at the bottom end of the range for P. leoninus but below the size range for P. chrysophaeus.

[Alantb]

I think we're in funny country here anyhow. For instance, B&K Vol 4 p.126 equates Pluteus phlebophorus with P. chrysophaeus which seems completely wrong, especially if you take any notice of the names. ('Chrysophaeus' = dusky gold, I think?)('Phlebo-' implies veined)
But you are right about the cystidia Ken, I had (of course) forgotten; I wonder what will happen when the splitters get hold of this one????

[Leif]

According to British Fungus Flora 4, Pluteus phlebophorus is "umber or date-brown, more rarely sepia, ...". The common name "Wrinkled Shield" gives a clue as to the nature of the cap.

However, the same volume includes "Misident. Pluteus chrysophaeus", and there appears to have been some confusion. But I would have thought that was well in the past.

The Basidiomycota gives "Pluteus chrysophaeus sensu auct." under Pluteus phlebophorus. Hopefully someone can remind me of what we concluded "sensu auct" meant.

[mykonik]

Originally Posted by Leif

I am sure most of you would have narrowed this one down to a Pluteus:



Collection notes:

"Berkshire, 22 May 1997, on rotten Beech, cap bright yellow with brown areas, diameter about 6cm. Gills pale pink. Stem twisted, white. Margin lined, cap silky. Spore print deep salmon pink. Spores smooth sub-spherical 6x5 um2."

I do not think it is Pluteus luteovirens, which is fairly common in the south, partly due to the large size, but also the jizz is not right. The silky cap and brown markings do not fit.

It ticks most of the boxes for Pluteus leoninus (size, silky cap, whitish stem, pale pink gills, spores in the right ball park), but what about the distinctive brownish regions on the cap, especially at the centre? From photos I have seen, the texture of the cap especially at the centre is correct i.e. sort of granular. The BFF Volume 4 mentions buff stippling especially at the centre. But I hesitate to assign it to Pluteus leoninus, which I am not familiar with.

Unfortunately the impression I have from the literature is that I will get nowhere without microscopic examination, especially of the cap cuticle. Unless someone is very familiar with the species in question ...

Comments welcome.

Hi Leif - this Pluteus looks very interesting !

It might be a New British Record ! Do you have the material by any chance - if so it should be sent to Kew. I note that you have given a spore size so you may still have the specimens ??

It is not P. chrysophaeus (= P. luteovirens, = P. xanthophaeus = P. galeroides,) !

I also don't think that it is P. leoninus (colour of the cap is wrong for a start) - you could easily check that by looking to see if the cap cutical is filamentous (i.e hyphal) - all of the other yellow or yellowish Pluteus species (mentioned above) have a totally different cellular cap cuticle !

There are two things it could (possibly) be in that case.....

If the gill edge was brownish then it is approaching something called Pluteus variabilicolor, descibed from Hungary ba a lady called Babos - this is illustrated in Courtecuisse & Duhem (page 284) BUT the only thing that makes me wary of saying it is, is that it should have the stipe covered in minute blackish punctae (scales) - your specimens don't appear to have that, and the cap is illustrated as a REALLY bright yellow !

If the gills are edges yellowish then we could be looking at Pluteus leteomarginatus Rolland, a European species not yet found in Britain. This is supposed to look somewhat like P. leoninus but have the cap with brownish coloured tomentum (velvety scales)


Very interesting (and another stunner of a picture !)

Nick

[Leif]

Thanks Nick. I wondered about Pluteus luteomarginatus. The bad news is that the original specimen turned into a putrescent soup soon after collection.

Regarding the gill edge, here is a 100% crop from the slide scan:



Maybe the gill edge needs to be viewed head on. I did not note the gill edge colour at the time of collection.

I originally ruled out Pluteus variabilicolor for the reason you give i.e. the stem being wrong.

I see what you mean about the resemblance to Pluteus luteomarginatus:

Pluteus luteomarginatus

I would say it is a dead ringer. But then again, that is hardly scientific.

It looks like this will have to remain as an unknown Pluteus species. I tried to refind it in later years without success and I am no longer allowed to collect in the locale, as I got 'caught' by Ted Green and a car load of mycologists, who pointed out that I needed a permit. He gave me one for a year only.

Is there any point in passing the photo under the noses of Kew?

[mykonik]

Originally Posted by Leif

Thanks Nick. I wondered about Pluteus luteomarginatus. The bad news is that the original specimen turned into a putrescent soup soon after collection.

Regarding the gill edge, here is a 100% crop from the slide scan:



Maybe the gill edge needs to be viewed head on. I did not note the gill edge colour at the time of collection.

I originally ruled out Pluteus variabilicolor for the reason you give i.e. the stem being wrong.

I see what you mean about the resemblance to Pluteus luteomarginatus:

Pluteus luteomarginatus

I would say it is a dead ringer. But then again, that is hardly scientific.

It looks like this will have to remain as an unknown Pluteus species. I tried to refind it in later years without success and I am no longer allowed to collect in the locale, as I got 'caught' by Ted Green and a car load of mycologists, who pointed out that I needed a permit. He gave me one for a year only.

Is there any point in passing the photo under the noses of Kew?

Hi Leif,

I can't see any yellow in the gill edge of you cropped shot - and since you say the specimen dissolved it'll be a mystery for ever - but at least you got a brilliant image of it !

No, I don't think it's a good idea to send Kew the photo (they are far too grand for that - would need the specimen !)

I too got caught by Ted Green (in Windsor Great Park) and I too got a permit out of it - how odd - but mine was for five years (since I was associated with Kew) so he thought I was 'something' in the mycological world - deluded or what !!

Nick

[badgerwatcher]

It is very beautiful.

[Fungus Ken]

Originally Posted by mykonik

If the gills are edges yellowish then we could be looking at Pluteus leteomarginatus Rolland, a European species not yet found in Britain. This is supposed to look somewhat like P. leoninus but have the cap with brownish coloured tomentum (velvety scales)

I saw the reference in BFF4 to Pluteus luteomarginatus and the fact that the cap has an upper layer of brownish cells over the yellow ones. But when I referred to FAN2, I discovered that Vellinga considers Pluteus luteomarginatus Rolland to be a synonym of P. leoninus.

So the description of the cap colour of P. leoninus in FAN2 would encompass the specimens in the photo because it includes a wider variability in colours including yellow-brown, not just the lemon-chrome of BFF4.

For P. leoninus FAN2 says the gill edge is "yellow when young, later whitish but sometimes remaining yellowish near the margin of the pileus".

So the yellow margin to the gills should also be present in young specimens of P. leoninus but the colour obviously fades to whitish as the specimens age. Vellinga clearly does not think there are enough differences to separate P. luteomarginatus out as a different species.

So if you follow the lumpers, there is no reason to rule out P. leoninus (but obviously it would not be as exciting as finding a species new to Britain).

Ken

[Fungus Ken]

I've done a bit more browsing on Pluteus leoninus.

The following German website on Pluteus includes P. luteomarginatus as a synonym of P. leoninus:

http://www.tham-thueringen.de/tham/html/pluteus.html

So the Dutch are not alone in considering the two species to be synonymous. Maybe not surprisingly, Krieglsteiner also includes P. luteomarginatus as a synonym of P. leoninus in Die Großpilze Baden-Württembergs Band 4.

There is a photo on the German Pluteus website of P. leoninus:

http://www.tham-thueringen.de/tham/g...us_930906a.jpg

Although the cap colour is brighter yellow than Leif's specimen, there are distinct brown scales towards the centre of the cap.

Interestingly, Nordic Macromycetes Volume 2 says for P. leoninus that the cap colour is golden yellow to lion yellow, which is presumably where the epithet leoninus comes from.

So now I just need to browse the web for a few photos of lions to see what colour they are...

Ken

[Leif]

Ken: Like you I have done lots of Googles and I've seen images of Pluteus leoninus with some brown on the cap centre. However as with all of these things, it is hard to comment unless we know who has done authoritative studies - c.f. Boertmann and Hygrocybe - and who is simply collating received opinion. Who knows if it is an extreme form of the same species, or a new species. And without microscopic examination, I doubt we can say anything definite. But at least we do know that it is consist with something in the leoninus/luteomarginatus group.

[FungiJohn]

This has been verified as Pluteus leoninus



As is this example showing the brown cap centre



John

[Fungus Ken]

The second photo seems to show some yellow on the gills, near the margin of the cap, as per the description in FAN2.

It would be useful to know who has done some definitive work on Pluteus but, without this information, I agree with Leif that we can only go as far as saying his specimens appear from the photo to be in the group around Pluteus leoninus.

Ken

[FungiJohn]

I think it's the usual problem Ken. Some species are never quite that simple

John

[mykonik]

Originally Posted by Fungus Ken

The second photo