Observation 6003: Leratiomyces ceres (Cooke & Massee) Spooner & Bridge
When: 2008-01-12
No herbarium specimen

Proposed Names

87% (4)
Eye3 Eyes3
Used references: DNA analysis shows that Stropharia aurantiaca and Psilocybe ceres are the same and belong in the genus Leratiomyces. Also transferred are L. cucullatus (Weraroa), L. erythrocephalus (Secotium), L. magnivelaris (Naematoloma), L. percevalii (Psilocybe) and L. squamosus (Psilocybe). Bridge, Spooner, Beever & Park. 2008. Mycotaxon 103: 109-121.

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Eye3 = Observer’s choice
Eyes3 = Current consensus

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Taxonomic status of this group
By: Peter G Werner (pgwerner)
2008-04-11 15:07:38 PDT (-0700)

“In the paper by Bridge et al., they reanalyzed those data, with more sequences, but again only from LSU, and then (with a restricted data set) Leratiomyces and Stropharia are sister clades.”

Interesting – that’s where I thought it came out. To my mind, the more nomenclaturally stable way to have classified this would have been to simply gone with a prior classification scheme that accepted this group as a subgenus of Stropharia. I’m pretty sure such classifications are already in existence, and barring that, Stropholoma sensu Singer could have been elevated from sectional to subgeneric status.

But its the author’s prerogative to simply erect a new genus, particularly if there’s a member with an established genus name already. In fact, I’m not clear on this, but rules of priority may actually force one to do this. The downside is that it creates a lot of name changes that I’m sure are going to tick a lot of people off. The upside is that its a step toward creating a more restricted (and therefore more clearly-defined morphologically) definition of Stropharia proper. Though what needs to happen next is to erect a new classification for Stropharia semiglobata and allies, which last I read, really aren’t close to the true Stropharia at all.

Morphological characters
By: Peter G Werner (pgwerner)
2008-04-11 14:57:31 PDT (-0700)

“Bridge et al. put several species in Leratiomyces, but they fail to give a morphological description of this genus.”

That’s unfortunate – however, I believe there have been morphological definitions of Stropholoma published before. In fact, I’m pretty sure Noordelos gives a description in FAN (as with all dark-spored Strophariaceae, he treats Stropholoma as a subgenus of Psilocybe).

The uniting characters I remember the most are 1) the relatively large, thick-walled stropharioid spores, and 2) the presence of very long, cylindric cheilocystidia. I believe these traits are present in all species, though I could be wrong.

An unusual character of L. ceres/S. aurantiaca is a very well-defined hypodermium underneath the cutis. This, of course, is a well-known character of Hypholoma, which is why it was transfered by some authors from Stropharia to Hypholoma/Naematoloma. North American authors then tended to put it in the later genera, while Europeans kept in Stropharia.

Taxonomic status of this group
By: Peter G Werner (pgwerner)
2008-04-11 14:44:50 PDT (-0700)

I totally need to see this Mycotaxon article! Not online yet, unfortunately.

Basically, Stropharia aurantiaca, S. riparia, and others cluster closely together, as has been mentioned. Where this cluster comes out is less well defined – the last paper I saw on it was Moncalvo, which had this group in a sister relationship with the “true” Stropharia, though with very poor cladistic support. If this relationship was accurate, then my feeling was that the most nomenclaturally conservative strategy was to accept this as a subgenus of Stropharia, Stropholoma. There are a number of classification schemes that accept Stropholoma as a section of Stropharia, and I believe one that elevates it to subgenus status.

In any event, I’d really like to see the paper on Leratiomyces, as it may have worked out the relationship between this group and the other Strophariaceae more clearly.

I see they found Weraroa cuculata was related as well. I’ve actually been aware of this for a few years – I found this out by downloading a sequence that Heather Hallen took a few years ago, and then putting it into the Moncalvo tree to see if it fell out anywhere. It tightly clustered with S. percevalli, and certainly, its micro-morphology fits well. Not publication-worthy, obviously, but I feel vindicated by the results found in this paper.

Others that should be considered as part of this genus, though unfortunately the authors of this paper never had a look at it – S. riparia, both in its true form, as seen in the Pacific Northwest, and the “freeway Stropharia” so common in the Bay Area, which typically gets called S. riparia, but is not the same thing. (And the “freeway Stropharia” itself has two morphological forms, though I’m unclear that these are really different species.) Its actually closer to S. percevalli, if anything, though S. percevalli, S. magnivelaris, and all forms of S. riparia are pretty close.

I’m glad somebody is working on this and will make a point of getting some “freeway Stropharia” collections to them next season.

two things are at stake – the species name and the genus name
By: else
2008-04-11 11:51:42 PDT (-0700)

It was long known that the species name, aurantiaca, was misapplied. Originally it was described as a forma of Str. squamosa (actually of Agaricus squamosus), and another name for this taxon is Str. thrausta – it is a slender, forest dwelling (Fagus forests in Europe) species, without chrysocystidia.
Psilocybe ceres, described from Australia, fits the bill of what we call Str. aurantiaca (or H. or Neamatoloma aurantiacum).

The genus name is a different story.
Leratiomyces is a genus erected for secotioid species from New Caledonia.
In the big over view of the Agaricales by Moncalvo et al. (2002) in which 117 clades were recognized (based on LSU data only) , aurantiaca, magnivelaris, Weraroa erythrocephala and a Leratiomyces species cluster together, separate from the rest of Stropharia.
In the paper by Bridge et al., they reanalyzed those data, with more sequences, but again only from LSU, and then (with a restricted data set) Leratiomyces and Stropharia are sister clades.
Bridge et al. put several species in Leratiomyces, but they fail to give a morphological description of this genus.

.
By: Erin Page Blanchard (CureCat)
2008-04-10 15:14:05 PDT (-0700)

>
>Has anyone pinged Peter Werner about this?
>I’d love to know his opinion on this article.

“Peter was saying that This species along with S. riparia do not fit smoothly into Stropharia, and that a new genus altogether should perhaps be erected for these two phylogenetically close relatives.”

So yes, Peter said that Stropharia is a closer fit than Hypholoma or any other synonym. If I recall correctly, it was the microscopic differences shared by S. aurantiaca and S. riparia that suggest a separate lineage apart from other Stropharia.
So who knows, maybe a sub-genus or new genus will some day be created…. I know everyone would LOVE that. ;)

Mind and tongue twisting!
By: Nathan Wilson (nathan)
2008-04-07 22:08:05 PDT (-0700)

Thanks for the update. Has anyone pinged Peter Werner about this? I’d love to know his opinion on this article. I’d be interesting in reading it as well if you have a chance to send it my way.

org.
By: Debbie Viess (amanitarita)
2008-04-05 17:20:19 PDT (-0700)

doesn’t the rapidity of latin name changes on some of these mushrooms amount to cruel and unusual punishment of mycologists? there oughta be a law…

worst of all, it’s such a common one that we’ll all have to memorize it!

Fixed up synonymy
By: Nathan Wilson (nathan)
2008-01-15 09:13:06 PST (-0800)

The two names were connected. At first I thought I’d leave Hypholoma aurantiacum as a valid ‘co-synonym’, but since most people on the site have switch to using Stropharia it seems reasonable to reflect that.

Reference for the name change
By: Darvin DeShazer (darv)
2008-01-14 22:11:07 PST (-0800)
.
By: Erin Page Blanchard (CureCat)
2008-01-14 12:31:43 PST (-0800)

Yes, this is the same. The currently accepted nomenclature is Stropharia aurantiaca, though it has been juggled back and forth from Hypholoma to Stropharia. Didn’t we briefly discuss this? Peter was saying that This species along with S. riparia do not fit smoothly into Stropharia, and that a new genus altogether should perhaps be erected for these two phylogenetically close relatives.

Was this Hypholoma?
By: Douglas Smith (douglas)
2008-01-14 12:24:08 PST (-0800)

This is the same as what was called Hypholoma? If that is true, is there a source on why this was changed? Just wondering here…

Created: 2008-01-12 16:50:38 PST (-0800)
Last modified: 2008-01-12 16:50:38 PST (-0800)
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