Observation 10308: Entoloma undatum (Fr.) M.M. Moser

When: 2008-08-14

Collection location: Jonesville, New York, USA [Click for map]

Who: Douglas Smith (douglas)

Specimen available

Found under oaks and pines in moss. These were quite small, less than 2cm in diameter. With the grey colors and pinkish tones in the gills, these seem like Clitopilus prunulus. That one usually is fleshier (is that a word?), with a smooth cap, so these look a little different, and not sure what they are.

9/7/2008 – Looking at the spores under the scope, hoping I can tell something from a quick look.

The micro-shot here is of some tissue from the stipe apex at 1000x in Meltzer’s. There are spores on the surface here, and they are non-dextrinoid and inamyloid, and I can’t say much more than that. They are perhaps the strangest looking spores I’ve seen, completely irregular, and unfortunately this doesn’t fully come through in the photo. The spores are lumpy, with bumps and points, not angular, not striate, just completely random.

I though perhaps as they are greyish, with gills that have pinkish tones, the spore could be angular-striate and I could say these are small Clitopilus prunulus. Not so much, I still have no idea what these are, the spores are so strange it didn’t help looking at them…

9/27/2008 – Looking back at these…

Looking over more info, it looks like the randomly shaped spores that are angular in profile are Rhodocybe. In the west it seems that the common (sort of) Rhodocybes are R. nucliolens and R. nitellina. In the east it seems the common Rhodocybe is R. mundula. Looking at this one closer, I get the spore size as :

Ave spore : length – 8.76 +/- 0.45 (err 0.12) um, width – 6.06 +/- 0.42 (err: 0.12) – q : 1.45 +/- 0.11, on 16 spores.

And this is too large for R. mundula, which should have a spore size of 4-6 × 3.5-5 µ. It turns out there is another small grey Rhodocybe, with decurrent gills, and this is R. caelata. Looking around for other sources on this, there is a similar photo, so it is promising. Although I’d like to see good descriptions for these Rhodocybes before I’ll be confident of this.

9/29/2008 -

One more comment, I popped a gill under the scope again on these. It turns out that Rhodocybe has sections, and R. caelata is in the section with hymenal cystidia. And under the scope these do have cystidia at least on the gill edge. They are small, just at the same height at the basidia, and sparse, about every 10-20 or so basidia on the fertile gill edge. Uncertain about on the gill face, there were too many spores there in these mature caps. Thats makes this id more convincing with the random angular spores, and existance of cystidia.

Unfortunately the photos of the cystidia came out to grey and blurry to real be able to show the difference between the cystidia and the basidia in the shots, so I won’t confuse the issue by posting them.

Species Lists



Proposed Names

29% (1)
Recognized by sight: Small, grey, pinkish tones in gills.
-59% (2)
Recognized by sight: Similar to other photos, and strange randomly shaped, mostly angular spores.
Used references: Mushroom Expert
-82% (3)
Used references: Mushroom Expert, Mushrooms Demystified, Rhodocybe pages: http://www.entoloma.nl/html/rhodocybeeng.html
43% (3)
Eye3 Eyes3
Recognized by sight: looking OK and spores are right..

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Eye3 = Observer’s choice
Eyes3 = Current consensus


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Created: 2008-09-01 16:08:54 CDT (-0400)
Last modified: 2008-09-07 15:53:43 CDT (-0400)
Viewed: 460 times, last viewed: 2018-09-20 18:33:40 CDT (-0400)
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