Observation 21334: Panaeolus cinctulus (Bolton) Britzelm.

When: 2009-05-25

Collection location: Hercules, California, USA [Click for map]

Who: Alan Rockefeller (Alan Rockefeller)

Specimen available

Growing in grass, lemon shaped spores, 13 – 15 × 7.8 – 8.8.


Copyright © 2009 Workman
Microscopy composite by Workman
Spores 1000x
Spores 1000x
Spores 1000x
Spores 1000x
cheilocystidia 400x
cheilocystidia 400x
cheilocystidia 400x
cheilocystidia 800x
cheilocystidia 800x
This is the same image as below, with a lot more contrast.
cheilocystidia 800x
A two spored basidia, 800x
Copyright © 2009 Workman
Grain spawn
When cultivated by Workman, the resulting fruits looked much more like typical Panaeolus cinctulus

Proposed Names

90% (2)
Based on microscopic features: My own microscopy didn’t reveal any 2-spored basidia, but I also wasn’t able to see more than two sterigmata at any one focal plane. All microscopic features typical of Panaeolus cinctulus.

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

= Observer’s choice
= Current consensus


Add Comment
By: Alan Rockefeller (Alan Rockefeller)
2009-05-28 15:48:48 CDT (-0400)

I took another look at these this morning. I saw a lot of two pronged basidia and none with four sterigmata. I still didn’t see any cystidia so I washed the spores off a gill fragment in the sink and I was able to uncover some.

By: Erin Page Blanchard (CureCat)
2009-05-28 02:49:12 CDT (-0400)

I just went through a few keys and reviewed a bunch of descriptions and I cannot find any descriptions which come close.

Whatever it is, there is some intense bluing on at least one of the cap margins, and subtle blue on the caps and stipe bases of 4 or 5 others.

There aren’t that many described species of Panaeolus, so this is potentially something new (surprise, surprise…).

A yup -
By: Douglas Smith (douglas)
2009-05-28 01:40:37 CDT (-0400)

Yup, that thars the question, alright.

Definitely not…
By: Erin Page Blanchard (CureCat)
2009-05-28 00:41:24 CDT (-0400)

…A Psathyrella or Panaeolina.

These are without doubt, Panaeolus. The questions remains- which species?

Is that a feature of some Psathyrella types…
By: Douglas Smith (douglas)
2009-05-28 00:35:15 CDT (-0400)

I forget the details of the Psathyrella monograph, is that a feature of some section, a lack of cystidia. One annoying thing of certain Psathyrella types is that the cystidia are basidia shaped, although usually larger. I wonder if there are some where the cystidia not only are about basidia shaped but of similar size.

By: Alan Rockefeller (Alan Rockefeller)
2009-05-27 23:35:39 CDT (-0400)

I have looked at these about 6 times under the scope.

I haven’t seen any cystidia, which is pretty unusual.

The spores are smooth here…
By: Douglas Smith (douglas)
2009-05-27 19:51:47 CDT (-0400)

Well the spores are smooth here, so these aren’t Panaeolina, they are just Panaeolus.

By: Shane Marsh (Mushane)
2009-05-27 19:23:16 CDT (-0400)

Yeah I dont think ide go as far as to calling them Panaeolus bisporus, but I see where your coming from on that, and I have no ideas as well.

Gumby from the shroomery was finding some strange lawn pans as that were seemingly just like those.

By: Erin Page Blanchard (CureCat)
2009-05-27 17:25:29 CDT (-0400)

I saw bluing on at least two of the caps. Is P. bisporus out of the question??

Out of 10 of the mushrooms that we were not sure if they were Panaeolus or Panaeolina, 2 had brown prints, the other 8 were black.

*Edit: Nevermind, these are microscopically very different from this P. bisporus collection:

By: Erin Page Blanchard (CureCat)
2009-05-27 16:22:59 CDT (-0400)

Hmm… How many grass-dwelling Panaeolus species have 2 sterigmate basidia? I can only think of P. bisporus.

Remember the Panaeolina foenisecii I gave you with the other mushrooms before you left? Did you get a spore print?
I kept them when we were hunting because some looked black spored. I did spore prints and the majority appear to have black spores after all. I think they’re probably more of this same species. I will look for bluing.

By: Alan Rockefeller (Alan Rockefeller)
2009-05-27 14:06:57 CDT (-0400)

Also the stem on the smaller one appeared to have some bluing on it, and the cap is blue in several places where it was damaged.

as usual
By: Shane Marsh (Mushane)
2009-05-27 13:38:16 CDT (-0400)

great microscopy

2 spored
By: Alan Rockefeller (Alan Rockefeller)
2009-05-27 13:20:07 CDT (-0400)

All the basidia I observed were two spored. There were a lot of random spores around so its hard to be sure. I observed this in the MV collection as well.

By: Erin Page Blanchard (CureCat)
2009-05-27 06:22:08 CDT (-0400)

If that is a basidia and not cheilocystidia, do you think some of the basidia are 2 sterigmate? ‘Cause I can’t see how that could have 4 sterigmata, but the basidia next to it looks like it does.

Created: 2009-05-26 21:19:57 CDT (-0400)
Last modified: 2018-03-23 00:49:51 CDT (-0400)
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