Today's ID Challenge

[82t]

Hi

today's find, for ID confirmation, if possible, please.

Based on my research in the WAB directory, it's most likely Agaricus Silvaticus, though I think it looks more like Agaricus Bohusii. Rarity factor makes that unlikely. Might equally be Agaricus langei, but the markings are more like the above, I think.

Found beneath a pine in a small cluster, with a second cluster 2 or 3 metres away underneath a holly-type bush. Chestnut tree close by, and a lake 8 metres away.

Stems are quite woody on some of the longer-dead examples, and reasonably maggotty. Lovely!

[Ditiola]

Hi

Try cutting them in half: What colour does the flesh turn in the stem, cap and stem base?

A. silvaticus is one of the red staining species

However, you really need a microscope and a good key to arrive at an accurate ID with Agaricus.

There is a new key just published. I have ordered mine today! although nbhs are waiting for stock: It is called 'The Genus Agaricus in Britain' by Geoffrey Kibby .


Peter

[Lancashire Lad]

A.bohusii generally grows in dense caespitose groups. So, besides rarity factor, that too would go against these being that species.

With only the information available from these photos, there are far too many options still available using the Kibby synoptic keys.

From what is shown, we have:-

Caps coloured with distinct thin to thick scales "C"
Flesh changing Red or not (and where) "?"
Ring - superior (peels upwards) "H"
Stipe cylindrical to clavate or bulbous "L"
Young cap margin not prominently inrolled "O"
KOH reaction + or - "?"

And keying out with C?HLO? leaves too many possibilities.

So, in order to narrow things down a little more, we would need to know if the flesh turns red as per Peter's response, and also, whether they have KOH positive or negative reaction.

Regards,
Mike.

[82t]

Thank you both - and a Commander of the Wild Empire as well. Excellent!

Are we agreeing then that they are definitely/highly likely some form of Agaricus?

I've sliced them as advised and, apart from the profusion of maggots, they are staining red on the gills, though not really on the cap flesh.

I've looked up KOH on the site and it appears to be a process for someone more serious than me, at this stage (correct me if I'm wrong!), so can't give you that info tonight.

Thanks Peter for the book recommendation, I'll look into that too.

Regards


Cillian

[Ditiola]

Thanks Peter for the book recommendation, I'll look into that too.

Regards


Cillian

The book will probably not be all that usefull without a microscope. Perhaps something to work towards for the future

Peter

[Lancashire Lad]

Certainly an agaricus.

With the red staining, it might take a while between cutting and the full staining reaction, so you need to keep an eye on it for a couple of hours to be sure.

Yellow flesh (or yellowing on cutting) is another ID factor which can narrow the field too.

When you say they have stained on the gills, are you meaning on the actual gill lamellae (blades) or in the flesh immediately above the gills?

The relevant identification factor for red staining is really a reference to staining of the flesh in the cap/stipe/cuticle.

According to Kibby:-

In A.bohusii, the flesh would (should) be pale brown, staining reddish to reddish-brown then dark brown. (But I don't think it's that species from the photos).

In A.sylvaticus, the flesh should be white, staining bright cherry red in the pilius and upper stipe.

But it still leaves several other possibilities.

Regards,
Mike.