Observation 7652: Psathyrella spadicea group
When: 2008-05-30
Herbarium specimen reported

Notes: medium to large mushroom, clustered all around the base of (live) aspen, but not directly on wood, absolutely no odor
ST: 80 × 10 mm, thickening slightly toward base, whitish, smooth, shiny, fibrous, firm, splitting when bent, solid, whitsh inside, no bruising
CAP: convex, dry, smooth, dull, whitish with brownish disc and immediate margin, drying tan, margin sometimes splitting in several places for short distance, ~40-60 mm wide, cuticle cellular
VEIL: definitely none at any stage
GILL: attached, pale brown darkening to cinnamon brown, close, somewhat wavy, not very wide, edges minutely erose and paler than faces, tissue cellular neither divergent or convergent, cells ~60 × 20 µm clear rounded rectangles, didn’t see any droplets but it was dry
CYSTIDIA: bulbous base, conspicuously rising above basidia, tipped with nasty mace-like thing with 2-3 or more horns in all directions, ~30-40 µm tall, ~20 µm wide at base, ~15 µm wide at neck
SPORES: print brown, cinnamon en masse on gills, 8-9 × 4-5 µm, oblong, smooth, no germ pore or apiculus on any, usually slightly misshapen, either slightly bent or one end slightly larger, etc., weak fine texture inside, no oil bubbles

I searched for other populations in the area but failed to find any.

Proposed Names

-32% (6)
Based on microscopic features: See (copious) notes.
-51% (4)
Recognized by sight
Based on microscopic features
41% (3)
Recognized by sight
Based on microscopic features: thick-walled cystidia in sect. Spadiceae, close to P. cernua?
93% (3)
Recognized by sight

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

Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
By: Erin Page Blanchard (CureCat)
2011-03-27 12:28:55 PDT (-0700)

Cystidia micrograph for this species or something in the P. spadicea group. What Dimitar calls P. spadicea here is not precisely that, since it does not match microscopically nor the habitat described, but it is something close to P. spadicea.

Dimi’s spadicea

Are you sure
By: Alan Rockefeller (Alan Rockefeller)
2011-03-27 05:48:07 PDT (-0700)

that the spores do not have a germ pore? And are you sure that they are smooth? I have never seen metuloid cystidia in Psathyrella.

By: Irene Andersson (irenea)
2008-06-10 10:49:39 PDT (-0700)

In my opinion, almost everything points towards something close to Psathyrella spadicea:
The thick-walled cystidia with crystals, shape and size of the spores (without germ pore), colour of the gills, no veil, cap cuticle with rounded cells.
There is another possibility, a species that only differs in the colour of the spores, P. sarcocephala (cinnamon-coloured, according to Fungi of Switzerland).
There is a lot of confusion regarding P. sarcocephala – sometimes synonymized with the rather large P. spadicea, sometimes with the smaller P. cernua, the latter with more cylindric cystidia and smaller spores.

I’m no expert on these species myself, but if they have the right ideas about them in Fungi of Switzerland, I’d vote for Psathyrella sarcocephala.

These are pictures of Psathyrella spadicea:
(no visible crystals there, but they dissolve rapidly i KOH..)
(darker spores than Jason described)

Btw, there are no metuloids (thick-walled cystidia) in the genus Agrocybe, as far as I know.

Some of the terms
By: Douglas Smith (douglas)
2008-06-10 09:46:20 PDT (-0700)

Well, one reference that will have the terms and examples in one place is “How to indentify mushrooms to genus III: Microscopic features”, D. largent, D. Johnson, R. Watling. This will have the microscopic terms and photos of examples that will get used. A search on “mushrooms to genus III” on Amazon shows copies for sale for $21.

But the Cheilocystidia will be the sterile terminal cells at the edges of the gills (lamellae), and Pleurocystidia will on the faces of the gills. In some genus is it easy to tell, because the gill edge will be sterile (no basidia), and you’ll see all the cheilocystidia in a tight group on their own, and the pleurocystidia will be on the fertile gill face, and will be singular and surrounded by basidia.

In the second drawing you have there, you show a pleurocystidia. Also you say the cap surface is a brickwork, some call this “cellular”. If there is a gelatin matrix you get spaces between the cell walls that obscure the focus. But what you draw there looks like an epithelium, upward facing globose cells.

So, with pleurocystidia and no gelatin on the cap surface, its not a Hebeloma. With the cellular cap and the brown spore color, this kinda points to Agrocybe as the genus. Although I’m not sure the cystidia look like Agrocybe, but then again I’ve never looked at Agrocybe cystidia… I’ve been picking up some little guys at work for the past couple weeks, and keep meaning to get them under the scope, but I’ve got too many other samples to go first. Looking at the Flora Neerlandica I see that a few Agrocybes do have almost pointed cystidia with some form of incrustation on the end.

So, unless you want to do more work, my guess at this point would be Agrocybe.

By: Joshua Birkebak (Shua)
2008-06-09 23:11:05 PDT (-0700)

I would be inclined to think Inocybe with the large metuloids and smooth spores… It is awefully strange looking but i know here in the northwest we have a few odd ball Inocybe species that really don’t look much like the common members of the genus. Psathyrellas are not my specialty but the metuloids and the brown lamellae don’t quite look right though I wouldn’t rule it out completely.

By: Jason Hollinger (jason)
2008-06-09 22:19:40 PDT (-0700)

Errr… where are pleurocystidia found? Let me see if I have all this straight: caulocystidia are at the top of the stipe, cheilocystidia are on the edge of the gills, chrysocystidia are… what, yellow? I’m sure I’m missing a few.

I did not see any gelatinous matrix in the cuticle, it was a tightly packed brickwork of rectangular cells. I presume the hyphae would appear more sparse under LM if they were in a gelatinous matrix? I’ll upload a better drawing a made a few days ago.

I really need to get a book describing all these terms and techniques, don’t I? Any suggestions, or as in lichenology, does every mycologist define these things slightly differently, and as a result no authoritative manual exists?

Thanks for all the comments on this. I’m learning a lot.

This does not strike me as Hebeloma at all
By: Dimitar Bojantchev (dimitar)
2008-06-04 15:01:48 PDT (-0700)

This does not look like Hebeloma to me at all.

For Hebeloma the spores need to be roughened, also the
cheilocystidia has a different shape. I’ve not seen one that
doesn’t have the raphanoid odor.

If you have drawings of crystals on the cystidia then this may be
an Inocybe (although that it doesn’t strike me as one at all), ot
some Psathyrella have that feature too. This one likes a soli
saprophyte. Now all Psathyrella have an apparent apical pore,
while their spore print tends toi vary from very dark, blackish
brown to pure brown. I would not rule out Agrocybe either.

You need to do some more microscopy — this is the name of the
game with the brown spores species.

D. www.mushroomhobby.com
Cystidia look weird
By: Douglas Smith (douglas)
2008-06-04 11:52:58 PDT (-0700)

Check the pleurocystidia, Hebeloma doesn’t have pleurocystidia. Also Hebeloma will have a viscid cap, not dry, you can check to see if the cap surface has hyphae in a gelatin matrix.

voucher ready
By: Jason Hollinger (jason)
2008-06-01 17:27:46 PDT (-0700)

Yes, I’ve dried this one. I’ll double check the substrate before I leave, as well. Good excuse to go for one last walk. I’ll have to look at it again in a few years when (I hope!) I know a little more about mushrooms.

No clue….
By: Darvin DeShazer (darv)
2008-06-01 16:27:30 PDT (-0700)

The cystidia do NOT look like they belong to Hebeloma. How about part Inocybe and part Pluteus? I hope you saved them on the drier.

How about a drawing?
By: Jason Hollinger (jason)
2008-06-01 11:26:08 PDT (-0700)

Thanks for the help, Darvin! Best I can give you (without my camera) is a bad drawing. From memory, on top of everything else, so it might not all be perfectly to scale or accurate… but the overall shape is right.

If I’m wrong, and it’s not even a Hebeloma, what do you think it might be?? Mind if I move your comments into the genus notes?

Hebeloma books
By: Darvin DeShazer (darv)
2008-06-01 07:57:00 PDT (-0700)

The description of the cystidia seems very strange. A photo would be worth a thousand words! Hebeloma needs to be worked on in the USA.

Besides the book on the veiled species of Hebeloma by Smith, Evenson & Mitchel there is only ONE other publication devoted to Hebeloma. An excellent little book by Jan Vesterholt with 45 species that includes keys, full descriptions, microdrawings and a nice color photo of each species. Hesler was close to publishing a monograph for North America at the time of his death, but failed to finish it. It has 254 species and varieties with 101 descriptions of new species. No photos and sadly, no microdrawings, but it does have keys and full descriptions.

Hesler, L. R. 1976. North American Species of Hebeloma. Unpublished by the Author. 475+p.
Smith, A. H., V. S. Evenson and D. H. Mitchel 1983. The Veiled Species of Hebeloma in the Western United States. Univ. of Michigan Press, Ann Arbor, Michigan. 219p.
Vesterholt, Jan.  2005.  The Genus Hebeloma: Fungi of Northern Europe Vol. 3.  Danish Mycological Society, Denmark.  146p.

Created: 2008-05-31 21:16:32 PDT (-0700)
Last modified: 2011-10-24 17:29:42 PDT (-0700)
Viewed: 221 times, last viewed: 2016-10-25 02:04:25 PDT (-0700)
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