Observation 90947: Agrocybe pediades group

When: 2012-03-25

Collection location: Oakland Hills, California, USA [Click for map]

Who: Debbie Viess (amanitarita)

Specimen available

in grass.


stroph spores.jpg
dark, almost purple brown sporedrop.
1000x in water; ellipsoid with germ pore.
15-16 × 10-11 microns.
pileipelis a cutis.
encrusted?cystidia on gill edge; upper L and R quadrant.
ruh roh. these look like Agrocybe cystidia.

Proposed Names

-56% (5)
Recognized by sight: domed, viscid cap, dry stipe with little bulb at base, partial veil on cap edge, but disappearing with age. oddly ornamented/fissured cap, like veins of marble.
Based on microscopic features: brown gills/spores, too? taking spore print.
spore print very dark, almost purple brown.
48% (7)
Recognized by sight
-14% (3)
Recognized by sight: More medium brown gill color in older caps
Based on microscopic features: Spore color medium brown rather than darker golden-to-black, and not strongly truncate.
79% (4)
Eye3 Eyes3
Recognized by sight
-86% (4)
Based on microscopic features

Please login to propose your own names and vote on existing names.

Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
see Kuo’s site…
By: Debbie Viess (amanitarita)
2012-03-30 15:30:39 CST (-0500)

for a pretty spot-on description of this very (or very similar to) mushroom, within Agrocybe pediades group.


calling either of these spore prints “brown” w/out qualifiers is rather ridiculous, though. it is far from the usual browns found in Agrocybe.

macro and micro matches, though.

I think we have a winner.

Got micrographs, but…
By: Peter G Werner (pgwerner)
2012-03-30 13:01:58 CST (-0500)

I got some nice micrographs of it, but boy, I’m stumped by the weird combination of characters on this thing:


I’d be glad to split the collection between you and Christian, Peter.
By: Debbie Viess (amanitarita)
2012-03-28 11:36:24 CST (-0500)

As to Roz Lowen and her workshop, oh yeah, I’ll be there! I’m the reason that she is coming out here to California! I’ve been trying to get her out here for years.

I’ll have a look at it
By: Peter G Werner (pgwerner)
2012-03-27 20:27:20 CST (-0500)

I’ll do some imaging on it if I can get part of the collection.

By: Noah Siegel (Noah)
2012-03-27 19:53:07 CST (-0500)

on ambigua 11-14 × 6-7.5 …

OK, um, I just redid the micro…
By: Debbie Viess (amanitarita)
2012-03-27 19:50:56 CST (-0500)

what I thought was a possible chrysocystidium looked encrusted at the apex, and I figured that was it. BUT, I didn’t originally mount it in KOH. When I did just now, no golden context and the cystidia actually bore a strong resemblance to Agrocybe cystidia. Dammit.

So, now we have a mushroom with purple brown spores, a viscid cap, a cutis, and fat bodied cystida with a short to medium long neck.

I’d be glad to pass this one along. Other than the pileipelis and the spore drop, it does lean towards Agrocybe. What else could it be???

By: Peter G Werner (pgwerner)
2012-03-27 19:44:58 CST (-0500)

Wow! Sounds to me like a highly ambiguous Stropharia ambigua, then.

I’d love to
By: Christian (Christian Schwarz)
2012-03-27 19:41:14 CST (-0500)

take a look at it – send it down to SC with Roz? Or Debbie if you’ll also be coming to the asco workshop, you can bring it down. It’d be totally neato if this was an atypical, nearly black-spored Stropharia!

I hadn’t noticed the spore print
By: Peter G Werner (pgwerner)
2012-03-27 14:46:52 CST (-0500)

Yep, the spore print certainly points in the direction of Leratiomyces (most likely) or Stropharia. Still, with dark spored mushrooms, I prefer the spore print on a black background to really make color differences pop out. Or, better, on a glass slide, where it can be looked at on white, gray, and black backgrounds.

I think more microscopy is in order, concentrating on two features:

1) Pileipellis – cellular type, like this:


is unambiguously Agrocybe. Cutis type points to other Strophariaceae.

2) Cheilocystidia – utriform (wide middle, long rostrum) = Agrocybe; long, thin, and cylindric = Leratiomyces; chrysocystidia that are clavate-mucronate to clavate-short-rostrate (wide middle-to-upper, short mucro/rostrum) = Stropharia.

Some helpful pages/pictures -





Stropharia proper:


bright brown…
By: Debbie Viess (amanitarita)
2012-03-27 14:02:41 CST (-0500)

like the cap print that you linked to Christian, is NOT the same as the dark purple brown, almost black, that this mushroom shows.

come to our meeting on Friday and see for yourself.

I’ll bite, Agrocybe camp…
By: Debbie Viess (amanitarita)
2012-03-27 13:47:41 CST (-0500)

show me an Agrocybe species with dark, purple-brown spores?

I sure couldn’t find one.

See spore print on cap of
By: Christian (Christian Schwarz)
2012-03-27 13:45:54 CST (-0500)
Gill color is wrong…
By: Noah Siegel (Noah)
2012-03-27 13:43:47 CST (-0500)

for Lerats, (Smoky-gray when young vs these Agrocybe brown ones…)

AS IF, Christian???
By: Debbie Viess (amanitarita)
2012-03-27 13:43:23 CST (-0500)

now you made me hafta do an “I’d call it that,” even though I meant that it “could be”…

yeah, yeah, the gills are brownish, but that spore print is purple-brown.

at least we are warily circling the possibilities, but I don’t think that we have quite nailed the ID yet.

Ain’t taxonomy FUN??! ;)

from MDM, page 469…
By: Debbie Viess (amanitarita)
2012-03-27 10:15:29 CST (-0500)

re: Agrocybe pediades…“the spores are neither purple-brown nor purple black as in Stropharia.”

Re: Agrocybe praecox group: “Stropharia sp. are also very similar but have a darker (purple-brown to black) spore print and stickier cap.”

These specimens had both a very sticky cap and purple brown spores. I will bring the spore print to the BAMS meeting on Friday night.

I get all the ways that this resembles an Agrocybe, but that spore print doesn’t fit.

By: Noah Siegel (Noah)
2012-03-26 23:55:46 CST (-0500)
That old dilemma again
By: Peter G Werner (pgwerner)
2012-03-26 23:38:18 CST (-0500)

Ah, the old “Is it in the Agrocybe praecox or Leratiomyces percevalii group” chestnut. Not easy to solve at first glance, nor even upon scoping it! I say Agrocybe praecox or a relative. (I don’t know the fine distinctions within that group.) That ID based on the dull brown gill color in the older caps and medium brown and not strongly truncate spores.

give it another look…
By: Debbie Viess (amanitarita)
2012-03-26 18:09:23 CST (-0500)

the spores don’t say Agrocybe to me.

I am scoping it today.

thanks Darv…
By: Debbie Viess (amanitarita)
2012-03-25 21:36:27 CST (-0500)

a much better fit than stropharia.

Created: 2012-03-25 21:09:23 CST (-0500)
Last modified: 2012-03-31 02:03:51 CST (-0500)
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