Observation 22420: Leratiomyces percevalii (Berk. & Broome) Bridge & Spooner

When: 2005-07-26

Collection location: Eisenberg, Thüringen, Germany [Click for map]

Who: Andreas Gminder (mollisia)

Specimen available


[admin – Sat Aug 14 02:00:13 +0000 2010]: Changed location name from ‘Eisenberg, Thüringen, Deutschland’ to ‘Eisenberg, Thüringen, Germany’



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transcontinental synonymie
By: Andreas Gminder (mollisia)
2009-06-23 12:47:02 CEST (+0200)

>>One of the reasons I am so hesitant to call things conclusively in a
transcontinental sense is because, for example, it appears based on
molecular evidence compiled by Noordeloos that our Entoloma bloxamii
is not too closely related to E. bloxamii from Europe […]<<

yes, certainly there are less species that are grwoing in Europe as well as in America. But I would like to see that theses restricted primarly to mycorrhizal fungi or at least to fungi occuring in natural habitats. What concerns L. percevalii, this is in Europe very probably are recently introduced species, expandning readily on wood chips and similar secondary biotops. We have some dozen of such species, e.g. L. aurantiaca, Psathyrella suavissima, or even formerly undescribed species as Agrocybe rivulosa, which have never been reported bevor 1980 or so despite of their remarkable easyness to determine. So it is quite conclusive to think that our percevalii in Europe may be introduced from America, as it seems to be not native here.

By: Dimitar Bojantchev (dimitar)
2009-06-23 09:38:57 CEST (+0200)

The taxonomic importance of chrysocystidia in Stropharia (and
Hypholoma), yes indeed, when I compare Machiels’ descriptions from
both Flora AN and Fungi Non Delineati Vol. XV (I think), it pretty
much boils down to that and perhaps 10-15% of avg. spore size
differential. I did find one chryso actually in the top picture of my
site, which really looked very much like percevalii.


One of the reasons I am so hesitant to call things conclusively in a
transcontinental sense is because, for example, it appears based on
molecular evidence compiled by Noordeloos that our Entoloma bloxamii
is not too closely related to E. bloxamii from Europe, despite the
superficial morphology hiding it quite well from us. But then again,
very few of us collect transcontinentally, which is a major weakness.

Andreas, as far as Stropharia ambigua — it is an entirely different
species, not even remotely confusable with anything else out there and
when you come to California I’ll take you to large patches of it,
which fruit continuously for 6 months at a time.

We do have a number of other apocryphical Stropharia in California,
which I will discuss at some point on MushroomTalk because they fall
somewhere between S. inuncta and infinity. And close to 0, of course,
which reflects how much we know of the Genus out West…

By: Andreas Gminder (mollisia)
2009-06-23 08:39:04 CEST (+0200)

Those chrysos are a main problem in this group, because separation of the species is based on the occurence or absence of them, as well as on the veil (fugacious vs. persistent). Chrysos are said to be seen in L. percevalii in young states only or even not (!), in L. riparia always not. So if you don’t find chrysos it means nothing …. Also the difference to L. magnivelaris lays mainly in the +/- persistent ring vs. the fugacious velar zone of L. percevalii. The fruitbodies are said to be more slender than percevalii and the occurnece in more natural biotops, but from both characters exeptions are admitted….
And there is a Stropharia ambiguum, which also should be considered as far as I know.
It seems are very difficult group to me, especially as I strongly doubt that the types of all these species contains (very) young fruitbodies to be absolutely sure whether chrysos are absent or not.
I will ask Machiel if he has some conclusion of this group as he worked with it when preparing the Flora Neerlandica and may be he did some molecular studies already.

Sending a bunch of California material to Noordeloos.
By: Dimitar Bojantchev (dimitar)
2009-06-23 06:44:19 CEST (+0200)

I put some effort into comparing the local Calfiornian “riparia” to percevalii and they come quite close. Did not see the chrysocystidia at all, even in young specimens. So, I’d not rush too hard to use the percevalii name yet (for California material). But you guys are free to do so :-) In the meantime I’ve collected a batch for Noordeloos to look them through and make a pronouncement.

D. (www.mushroomhobby.com)

P.S. Nobody knows what Smith’s S. riparia is exactly. The description is not very easy to work with. P. Werner studied the type, but hasn’t released any notes yet. And yes, I have asked for them…

not so complicated!
By: Andreas Gminder (mollisia)
2009-06-22 23:47:16 CEST (+0200)

The complicating factor in my eyes is, that there seem to be two different opinions on what Stropharia riparia is:
S. riparia in its original sense by SMITH (a fungus from rural biotops, but not on wood chips) and S. riparia in a misapplied sense (from wood chips) which is very close (or identical) to Leratiomyces percevalii (also exclusively on wood chips). As far as I have understood, that what you have found might be S. riparia in the misapplied sense and therefore not identical with the original diagnoses. But probably identical with L. percevalii. Whether the name L. percevalii took over S. riparia ss. orig. SMITH seems not very likely to me and whether it is the same as S. riparia ss.auct. has to be proven still. In the “worst” case there might be three taxa

Complicated, yes
By: Erin Page Blanchard (CureCat)
2009-06-22 23:27:07 CEST (+0200)

The species that we in the Bay Area call L. percevalli used to be referred to as S. riparia, HOWEVER, Peter Werner said that the mushrooms we were calling S. riparia did not actually fit with the original description of the species, and we had something different.

The confusing part is that L. percevalii is the preferred name for S. riparia, yet the description of L. percevalii fits with the species we find in CA, and it would appear to fit with the mushrooms in this observation as well… But if it is synonymous with S. riparia, then how and why does the original description of that species not fit??

the things are more complicate
By: Andreas Gminder (mollisia)
2009-06-22 21:20:42 CEST (+0200)

when you read the discussion in the link of Stropharia riparia. According to the author of this discussion there is a L. riparia ss.str. (means ss. A.H.Smith) and a L. riparia ss. ARORA. The L. riparia ss. ARORA may be synonymous to L. percevalii, but that has to be proven.
By the way, I have not heared of any european finding of L. percevalii occuring other then on woodchips …

By: Shane Marsh (Mushane)
2009-06-22 21:03:13 CEST (+0200)

this was formerly Stropharia riparia I believe.

Dude, where’s my micrograph?
By: Debbie Viess (amanitarita)
2009-06-22 17:32:30 CEST (+0200)

Nice to see another member of the genus Leratiomyces. We have one species that I know of that is common and introduced and fruits in wood chip beds: L. ceres.

Created: 2009-06-21 21:21:16 CEST (+0200)
Last modified: 2010-08-14 04:00:13 CEST (+0200)
Viewed: 362 times, last viewed: 2018-06-18 19:35:38 CEST (+0200)
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