Observation 117308: Agaricales sensu lato
When: 2012-11-18
No herbarium specimen
0 Sequences

Small mushrooms with max cap diameter under 1 inch. Growing in groups on a mossy hemlock log.

White spore print.


Spores at 400x in KOH. Add 17% to correct dimensions.
Spores in mix of KOH and Congo red.
I tried to focus on the gill edge. I think I may have succeeded, in which case the cylindrical projection is likely to be a chailocystidium; but I’m not sure.
Smash mount of gill. I don’t know whether the clusters of projections are cheilocystidia that got flattened, or tissue assoicated with cap context.

Proposed Names

48% (2)
Eye3 Eyes3
Recognized by sight
-29% (1)
Recognized by sight: Doubtful because this is a western NA species. See comments for a list of similarities.
29% (1)
Recognized by sight: See discussion.
5% (3)
Recognized by sight
44% (2)
Recognized by sight

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

Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
Spore quotient…
By: Dave W (Dave W)
2014-11-02 17:34:37 CST (-0600)

for Tricholomopsis species (ones easily checked in manuals) varies as follows: 1<Q<1.7. Spores seen here have quotient 2<Q<3. Also, late in the season for Tricholomopsis… at least in my local experience.

The only Lentinula species…
By: Dave W (Dave W)
2012-12-04 12:19:29 CST (-0600)

reported to occur in the wild in NA (for which I have found info) have a southerly distribution. This collection was made in cold weather… very few other mushrooms growing, ice and a little snow here and there.

But some info on spore size and shape for Lentinula types is similar to these spores. Also, some Lentinus species are reported to have cylindrical spores with q>2. The gills on this collection show wavy edges… perhaps serrate?

By: Irene Andersson (irenea)
2012-12-04 08:32:23 CST (-0600)

I’m getting Lentinula vibes

I doubt these are Rhodocybe because…
By: Dave W (Dave W)
2012-12-04 06:54:28 CST (-0600)

the spore print was pure white; fairly thick print disappeared against the white background.

Also, the spores appear to smooth… neither tuberculate nor angular. The shape is cylindrical to sausage-shaped with 2<q<3.

According to the info I have found about Rhodocybe, these spore traits do not fit the genus.

Thanks Douglas.
By: Dave W (Dave W)
2012-11-21 06:53:35 CST (-0600)

Not surprised about C. bakerensis (awaiting placement within Gymnopus) being highly unlikely. But I suspect this collection represents something close to this species. In this light, at least “Gymnopus” seems like a reasonable proposal.

I believe that mushrooms from Rhodocybe all have spore prints that are pink to light brown. This collection had a print that was clearly white. The print disappeared against a white background.

Collybia bakerensis
By: Douglas Smith (douglas)
2012-11-20 20:51:02 CST (-0600)

Collybia bakerensis really should be a Gymnopus, but no one has published that yet, it is still stuck at Collybia. But it is also only found on the bark of red fir, so that isn’t it here. Usually on the under side of the bark, between the bark and the rotting wood of red fir, after the wood is rotten enough that the bark has separated.

Difficult to come up with a reasonable proposal.
By: Dave W (Dave W)
2012-11-20 19:14:00 CST (-0600)

The one species which seems close to this obs is Collybia bakerensis, a PNW mushroom. My collection matches the description for C. bakerensis very well (list below), except the spores in my collection have 2<q<3, which appears to be too large a quotient for C. bakerensis. It is my undersatnding that C. bakerensis is unique amongst mushrooms currently placed within the genus Collybia, in that it does not occur on rotting fruit bodies of other mushrooms. So proposing “Collybia” for this obs seems like a dubious idea. Aside from the noted difference, here are the observed similarites to C. bakerensis:

Tiny fruit bodies with convex caps growing on rotting conifer log (hemlock). Grainy texture of tannish/pinkish cap surface (seen with lens). No pleurocystidia observed. Cheilocystidia observed, cylindric or cylindric/lobed. Occurence in cold weather; small patches of snow on the ground and icicles forming. White spore print.

A few of these dried specimens will be available for study, if anyone is interested.

I don’t think they are R. maculata.
By: Dave W (Dave W)
2012-11-20 12:39:50 CST (-0600)

The gills on this collection are too thick and widely spaced, and the occasional decurrent tooth doesn’t seem to fit R. maculata. Also, my concept of R. maculata is a much larger mushroom with a chalky white ground color beneath the blotches on the smooth cap. The little mushrooms in this obs have a sorta grainy (using lens) tannish cap surface. Also, although R. maculata is a wood decomposer, I usually find it growing on the ground.

But Collybia bakerensis is an interesting suggestion. I just did a quick online search, and it appears this is a western NA species. The accounts I glimpsed show mushrooms that are very similar to the ones seen here. Other similarities are growth on deteriorated conifer wood, and occurrence during cold weather. One trait mentioned is the presence of abundant cheilocystidia. Maybe I can gently rehydrate some of the dried material and look for cystidia…?

Thanks for the suggestions Britney.

How about Collybia bakerensis?
By: Britney Ramsey (Riverdweller)
2012-11-20 09:19:51 CST (-0600)

or Rhodocollybia maculata

Created: 2012-11-19 19:21:50 CST (-0600)
Last modified: 2015-12-29 10:56:18 CST (-0600)
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