Observation 108195: Agrocybe arvalis (Fr. :Fr.) Heim & Romagn.
When: 2012-09-02
No herbarium specimen

Notes: Don’t have a herbarium specimen, but I’m going to culture them and I can probably get more from where I collected them.

The striations on the cut sclerotia in the first picture are caused by a serrated steak knife, the sclerotia were pretty tough. I cut another one in half that had a hollow center was dryer and somewhat tougher to cut.


These are very tough, even with a sharp knife, there is tearing as the sclerotia binds to the knife edges.
I’m pretty sure I’ve seen these in other chip piles around here, but didn’t pick them, the ones I’ve seen previously, were more uniform than these though resembling Agrocybe pediades a lot.
The largest cap in this picture is an inch across.

Proposed Names

-44% (2)
Recognized by sight: http://americanmushrooms.com/store.htm, I saw them here about a week ago, the pictures I took without sclerotia, were taken about 2 weeks ago, I went back and checked if there were sclerotia today. They were growing in wood chip mulch in place that gets full sun, but it’s also has a drip line irrigation, that looks like it gets run
55% (1)
Recognized by sight
59% (2)
Eye3 Eyes3
Recognized by sight: Sclerotia & not much of a veil.

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Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
By: Jim Tunney (Jim Tunney)
2013-05-05 22:40:06 BST (+0100)

For the correction!

I’m not
By: Byrain
2013-05-05 22:12:11 BST (+0100)

entirely sure what Agrocybe arvalis (Fr.) Singer is supposed to be, but here is what looks like a good match for A. arvalis (Fr. :Fr.) Heim & Romagn. I guess its possible this observation could be it too.


Looks like
By: walt sturgeon (Mycowalt)
2013-05-05 21:55:37 BST (+0100)

two different species with dark sclerotia. I am only aware of Agrocybe arvalis (Fr. :Fr.) Heim & Romagn.

By: Byrain
2013-05-05 21:42:06 BST (+0100)

Do you think that is the same as Agrocybe arvalis (Fr. :Fr.) Heim & Romagn.?

By: Byrain
2013-05-05 19:23:21 BST (+0100)

I am doubtful against the author you used, not necessarily the name A. arvalis. And yea, I’m not sure any of the other species in fan6 has sclerotia as A. arvalis (Fr. :Fr.) Heim & Romagn. has, but that is a European source and I’m doubtful its fully comprehensive for the states.

Lastly, I don’t see any peeudorhiza and rhizomorphs are a common feature in Agrocybe.

Interesting suggestion, it would be cool if they were cospecific
By: Jim Tunney (Jim Tunney)
2013-05-05 19:06:54 BST (+0100)

They look very similar. In the second picture you can see some of what looks like pseudorhiza, the bit at the ends that was below the chips and has rhizomorphs attached. I’m calling them arvalis for now, because I haven’t seen sclerotia on any descriptions of pediades that I’ve seen.

By: Byrain
2013-05-05 18:24:40 BST (+0100)

I think Agrocybe arvalis sensu Singer = A. pediades, flora agaricina neerlandica vol 6 implies this at least. Agrocybe arvalis (Fr. :Fr.) Heim & Romagn. might be possible, but that species is also described with a pseudorhiza and you probably need microscopy to confirm that id.

Dave, I’m not sure
By: Jim Tunney (Jim Tunney)
2013-05-05 18:07:53 BST (+0100)

The mycelium on wood chips grew in a bus pan in an unheated garage. It hasn’t been wet enough for them to fruit where I found them and I don’t think they’ve turned on their drip line yet. Next time I go by I’ll see if there’s any still in the mulch. But that may not tell whether they were formed last year or this, as the ones that formed on wood chips in the bus pan formed in March and April after I had moved them to a slightly warmer place. http://mushroomobserver.org/89907?q=1D6KK look a lot like what I found, and that would be a good guess, scroll down to the base of this page, http://americanmushrooms.com/store.htm, there’s a description on how to fruit them if they’re arvalis.

Jim, do you know if…
By: Dave W (Dave W)
2013-05-05 17:51:31 BST (+0100)

these Agrocybe sclerotia persist in-situ throught the winter? The photos remind me of this obs.

A member of our local mushroom club gave me these a few years back. He said he found them while raking old fallen leaves in March. By the time I got them the texture was very tough, difficult to cut with a knife. The collector said they were somewhat softer when he first found them.

Created: 2012-09-03 04:41:22 BST (+0100)
Last modified: 2013-05-05 22:38:18 BST (+0100)
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