Mushrooms on compost heap

[Mercadante]

These mushrooms are growing under cover on our compost heap (which also contains horse manure). I wondered a) what kind they are, and b) whether it could ever be a problem, if poisonous mushrooms grew there? (Not that I intend to eat my compost, you understand! )

I am a complete fungus novice, but I tried to identify them in my New Holland Field Guide to mushrooms. The nearest in colour and shape seemed like Calocybe gambosa, and they did smell floury, but the cross section of the cap looked wrong. Reading the sticky here about identifying mushrooms to genus, I decided these were pluteotoid – volva absent, ring absent, free or finely adnexed gills. So: how extraordinarily wrong was I?

[fairplay]

Ouch, I don't like this one !
I've never seen an agaric (mushroom) start off with such a small head like these before, and they seem to be wrapped up in mycelium (the rooting/feeding system)

The top right hand photo seems to show the gills being pinkish, pointing to the Genus Agaricus, but I've an 'inkling' these are Ink Caps, becuz one shot seems to show the gills almost black.

What ever it turns out to be, it is doing your compost heap the world of good
i.e. making the heap 'work', so don't worry.

Neil.

[fairplay]

I've worked out (I think !) what's happened now, - you saw these mushrooms begin to pop up on your compost heap and you carefully prised away the muck to see what the hell they were and thankfully you took some photos.

Fungal spores are everywhere, and those which managed to germinate in your compost heap started to produce mycelium and when conditions were just right, the mycelium massed together to form fruiting bodies (mushrooms) which as they emerged in their embryonic stage, were still enclosed in the mycelium.

Don't know why the heads or caps are so small though, probably because they are babies ! So you photographed what your average fungus enthusiast wouldn't normally see - personally I'd be so excited to see what they will turn out to be that I would be afraid to disturb them, so you've given at least me, an insight as to what goes on 'down there'

Still not certain as to what you have though, but if they have turned into a blackish soggy mess by now then they could well have been an Ink Cap of some sort. Am I right..ish Mykonic ?

Neil.

[Mercadante]

You are quite right about how I found them. We have some old wool carpet over the heap, and when I pulled that back I just saw one or two mushroom heads, and brushed a little stuff from around them to see.

The gills were quite pale pinky-brown when I picked the mushroom, with what seemed a faint bluish tinge to the underside, but they have got darker with exposure to air and this morning look very dark brown and slightly mushy in spots, like the gills on shop bought mushrooms. Don't know that I'd say 'black', though.

[mykonik]

Originally Posted by fairplay

Ouch, I don't like this one !
I've never seen an agaric (mushroom) start off with such a small head like these before, and they seem to be wrapped up in mycelium (the rooting/feeding system)

The top right hand photo seems to show the gills being pinkish, pointing to the Genus Agaricus, but I've an 'inkling' these are Ink Caps, becuz one shot seems to show the gills almost black.

What ever it turns out to be, it is doing your compost heap the world of good
i.e. making the heap 'work', so don't worry.

Neil.

Yes Neil - I think that you are right about this - an inkcap, probably Coprinus comatus(or whatever it's new name is !) but what used to be called Coprinus ovatus, this now synonimised with C. comatus , being just a form with a rounded pileus.

Nick

[fairplay]

Double OUCH !!! Now I'm really out of my depth on this one, it seems to rule out Ink Caps (the stems looked too thick anyway)

You have really thrown a spanner in the works with your mention of a 'Blue tint underneath'

On the other hand, hopefully that might ring a bell with somebody else reading this (there's no bells in my brain)

I'm not familiar with any Entoloma, Pluteus, etc. on compost heaps that fit this description, which brings me back to Agaricus, but it does not look like an Agaricus

Of course, being a compost heap, anything organic gets thrown in, so it's just possible you have an alien in your pile !! Yes, that's it.... an Alien

Seriously, if I was in your shoes, I would take individual specimens in different stages of growth (photograph them first showing the caps from above and also, if you can get close enough, a shot of how the gills are attached to the stem) cut a mature one in half starting at the cap and going right down the stem, note any smell or colour changes to the exposed flesh (wait up to 10 mins aprox) then place the samples in an airing cupboard to dry slowly (2-3 days?), place in sealable sandwich bag and send, together with notes (very important) to the Mycology Dept at Kew Gardens.
Don't forget to mention about that apparent 'blueing' underneath.

That's about all I can do with this, and I'll bet as soon as I click the 'submit reply' I will see that 'Mykonic' (he's the 'in house' expert) has already identified this as the common so & so and I'll be red in the face

Neil.

[Mercadante]

Thanks Nick. So I went wrong right at the start, in thinking they didn't have rings!

Fungi are hard.

[Mercadante]

Thanks, Neil, too. It seems unlikely that we'd have anything rare here, so the bluish tinge may have been the work of my fevered brain - but I will certainly keep a hopeful eye and camera on them just in case.

[fairplay]

I knew it, I knew it !! why can't I keep my big mouth shut

At least you don't have to go through all that rigmarole now, (and if you look at the post times you will see how much effort I put into my replies - some might say I love the sound of my typing)

Neil.

[mykonik]

Originally Posted by fairplay

I knew it, I knew it !! why can't I keep my big mouth shut

At least you don't have to go through all that rigmarole now, (and if you look at the post times you will see how much effort I put into my replies - some might say I love the sound of my typing)

Neil.

Actually Neil, at least you go through things in a methodical manner so what's wrong with that - and you did arrive at the right diagnosis, albeit rather circuitously, but again that is the process for identifying things - often just following the visible clues presented by the specimen and then a process of elimination !

Nick