When: 2011-05-06

Collection location: Harden Flat, Tuolumne Co., California, USA [Click for map]

Who: Ron Pastorino (Ronpast)

Specimen available

These two groups of morels were found within a few feet of each other growing under pines at about 4000ft. I think they are most likely the same species, and what some call “Western Blonds”.
I wanted to see if there was any difference in the spores between the two groups.
The spores in general looked very similar(both from spore prints) and were on average somewhat larger in size than what I could find in the usual literature sources, although I only measured ~ 10 spores from each.
The lighter colored group were ~ 20.0-27.0 X 15.1-20.8 microns while the second group were ~ 24.8-30.0(39.6) X 17.9-21.8(27.0) microns. The second, darker group , may have been more aged.
These do look like what has been described as Morchella frustrata. The added feature being the lack of a “conspicuously lacunose stipe”.


Spores from the 1st group.
Spores from the 2nd group.
Spores from the 2nd group.

Proposed Names

16% (2)
Recognized by sight
52% (4)
Used references: first group has the lighter color, vertically-arranged pits, presence of indentation/sinus where cap attaches to stem, similar spore size to Kuo’s measurements (20-29 × 14-19). Kuo et al., 2012, Taxonomic revision of true morels (Morchella) in Canada and the United States
40% (5)
Recognized by sight

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

= Observer’s choice
= Current consensus


Add Comment
You are probably right Teri,
By: Ron Pastorino (Ronpast)
2016-05-28 16:21:17 PDT (-0700)

but in looking at the actual trees in both papers, the European material doesn’t always look like a 99-100% match to the North American material.
I was more curious to hear what Alan has found in comparing California material to the European and if they match up better than 98%.

Ron, just read the paper you referenced.
By: Terri Clements/Donna Fulton (pinonbistro)
2016-05-28 12:46:01 PDT (-0700)

It seems the conclusion supports M. tridentina after a study of both NA and European material: " Bayesian and maximum likelihood phylogenetic inference based on ITS region suggested that M.tridentina, M.elatoides, M. quercus-ilicis , and M.frustrata should be considered syn-onyms (Fig. 1), with the first being the prioritary epithet. This was further confirmed with complementary tef1 and rpb2
se-quencing (Table 2)."


Alan, have you read the Loizides et.al. paper
By: Ron Pastorino (Ronpast)
2016-05-28 07:40:03 PDT (-0700)

and looked at their tree? Also, have you done DNA analysis on any California M. tridentina/frustrata and compared the results with European material?

By: Terri Clements/Donna Fulton (pinonbistro)
2015-12-10 16:01:24 PST (-0800)

I can’t get the full text of the paper you mention. Do you have a pdf?

Terri, It looks like both papers came out at about the same time
By: Ron Pastorino (Ronpast)
2015-12-10 15:52:40 PST (-0800)

with Philippe Clowez as a common author.
With regard to the Morchella tridentina and Morchella frustrata, there seems to be some equivocality in both papers. They seem to assume that the two names are synonyms but fail to outright call M. frustrata invalid.
It appears all their work has been done on European M. tridentina material and in the phylogenetic tree only one sample exactly matched a French labeled M. tridentina while several others did not. And the one example of north American labeled M. frustrata seems to be taken from Kuo’s data.
There seems to be a little bet hedging here and I think Kuo et. al. M. frustrata should be given the benefit of at least a valid synonym until more work is done directly comparing the North American taxa with the European.

Hi Ron,
By: Terri Clements/Donna Fulton (pinonbistro)
2015-12-09 19:47:32 PST (-0800)

Thought this was the most recent look at morels: Mycologia, 107(2), 2015, pp. 359–382. DOI: 10.3852/14-166

  1. 2015 by The Mycological Society of America, Lawrence, KS 66044-8897 by Richards etal. Points to Morchella tridentina as the preferred name.


After reading this article again
By: Ron Pastorino (Ronpast)
2015-12-09 17:47:50 PST (-0800)

I’m not quite sure what the current status of the name for these would be.
Apparently there is still some discussion and more work needed to resolve the issue. There may be even an earlier name that would be more valid.
So, maybe Morchella frustrata is just a valid synonym until things are sorted out.
At least it’s my preferred synonym.

A recent paper seems to confirm that
By: Ron Pastorino (Ronpast)
2015-12-09 16:45:03 PST (-0800)
Morchella frustrata can still be considered a valid synonym until further DNA work can be done on North American material. http://www.academia.edu/12988160/Morchella_tridentina_M.rufobrunnea_and_M._kakiicolor_a_study_of_three_poorly_known_Mediterranean_morels_with_nomenclatural_updates_in_sectionDistantes

They used these photos as an example of Morchella frustrata.

Created: 2011-05-12 20:18:00 PDT (-0700)
Last modified: 2020-05-31 00:33:51 PDT (-0700)
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