Observation 87767: Psathyrella longipes group

When: 2012-02-13

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

Who: Byrain

No specimen available

Growing from leaf litter next to a duck pond, taste and smell both slightly nutty.

4-spored basidia present, clamps present, pleurocystidia absent, caulocystidia not found.
Cheilocystidia sizes = 28×11, 35×9, 35×12, 38×11, 42×11, 44×14, 46×11, 48×16, 49×7 μ

Spores truncate with conspicuous germ pore, usually 2 μ wide (Range (1) 2 – 3 μ), 20 spores were measured from the gills.
Spore range = (13) 14 – 16 × 7 – 9 μ
Average spore = 14.4 × 8.05 μ
Average Q = 1.8


Mounted in melzers
Mounted in KOH
Mounted in melzers

Proposed Names

24% (2)
Recognized by sight
Used references: North American Species of Psathyrella
Based on microscopic features
61% (2)
Recognized by sight: New name
Based on microscopic features
15% (2)
Recognized by sight: Psathyra fragilissima is a synonym, but that name is from 1926 and P. longipes is from 1895.
84% (1)
Recognized by sight

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Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
I found an old e-mail
By: Byrain
2015-12-17 16:57:24 CET (+0100)

Here it is explained about the synonymy by Andreas Melzer.

“The synonyms of Coprinopsis marcescibilis I have taken from other mycologists (Kits van Waveren, Örstadius, Ludwig), elwhaensis certainly seems to be a synonym.
Also P. fragilissima, but Lange, not Kauffman! The other similar species, such as P. thomii have not yet been tested. Unfortunately, very few of Smith’s material has been revised and sequenced so far. The spores of your record are really great.”

Seems when I originally made this observation as Psathyrella fragilissima (Kauffman) I could of misidentified it. Even Smith says P. fragilissima Lange is P. marcescibilis. Looking at the Smith description for P. fragilissima (Kauffman) it seems it also has the floccose-fibrillose outer veil that Coprinopsis marcescibilis is supposed to lack. Its not really possible to tell if there was much more of an outer veil in this observation before these photos were taken.

Psathyra fragilissima is a Coprinopsis marcescibilis synonym.
By: Byrain
2015-12-17 16:26:58 CET (+0100)


Even mycobank agrees.

Spores are variable in Coprinopsis marcescibilis
By: Byrain
2015-12-17 04:06:53 CET (+0100)

Both in shape and size, if Psathyrella longipes is a different species spores are doubtfully going to help distinguish them.

Hyaline spores
By: Byrain
2012-02-27 01:44:46 CET (+0100)

For my KOH mount, after sitting for a day give or take the spores started to turn hyaline. It appeared that the dry parts of the slide become so first. Though for observation 88247 of P. longipes which is a species dealt with in the same part of the key this was not observed, instead the spores merely become a lighter shade of brown.

Created: 2012-02-15 00:18:25 CET (+0100)
Last modified: 2016-09-02 02:54:47 CEST (+0200)
Viewed: 213 times, last viewed: 2017-09-28 23:20:18 CEST (+0200)
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