Taxonomic Swap 30060 (Guardado el 06/01/2023)

Añadido por cooperj el enero 17, 2018 08:20 TARDE | Comprometido por nschwab el 06 de enero de 2023
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Why is this change happening? I am unable to find any info in papers. Not enough proof that this was ever a separate species?

Publicado por dylantomtaylor hace más de 1 año

The swap remains in draft for discussion because of questions over synonymy and a chance for discussion. The swap has not yet been committed.
L. velutina is a name that continues to be used by some, especially in the USA.

Here is the background I'm aware of, and it might not be up to date, or correct...
L. velutina 1794 - type locality UK
L. lacrymabunda 1785 - Type locality France

The issues around the use and typification of various names in this group (L. velutina, L. lacrymabunda and P. cotonea) were discussed by Bas, C. 1983: On the application of the name Agaricus lacrymabundus Bull.:Fr. Persoonia 12: 103-106.
Bas concluded, following lectotypification of L. lacrymabunda, that it should be used as the correct name and L. velutina reduced to synonymy.

The view that L. velutina is a synonym of L. lacrymabunda is followed by European authorities I'm aware of, e.g.
Fungi Nordica
British Basidiomycete Checklist
Roy Watling's British Fungus Flora v4.
However, in the USA Smith in his monograph accepted the name L. velutina and it continues to be used in the USA by some.
There are asserted differences in spore morphology there is nothing to link differences to the original names. It would be tricky given the absence of physical types and the use of Bulliard’s plate as a lectotype. Epitypification might help, but that has not been done.

All the currently available data suggests these two names cannot be uniquely identified with available genetic data despite what is claimed by some writers.

Here are a couple published phylogenies showing the variation in names in the P. lacrymabunda clade ...
Fig100 in … Wächter D, Melzer A (2020) Proposal for a subdivision of the family Psathyrellaceae based on a taxon-rich phylogenetic analysis with iterative multigene guide tree. Mycological Progress 19(11): 1151–1265. https://doi.org/10.1007/s11557-020-01606-3
and,
Padamsee, Mahajabeen; Matheny, P Brandon; Dentinger, Bryn T M; Mclaughlin, David J 2008: The mushroom family Psathyrellaceae: evidence for large-scale polyphyly of the genus Psathyrella. Molecular Phylogenetics and Evolution. 46:415

I think the main issue is that the use of these names outside Europe has been become confused. I detect the usual story of the sometimes inappropriate application of European names for North American fungi, and sometimes these misapplications gain common usage in the USA despite changing opinions on their application in Europe.
Until/unless clarification, preferably by epitypification, then it seems appropriate to treat the variable use of names within this clade according to the nomenclaturally correct name, which is L. lacrymabunda, and in accordance with European views.
Phylogenetically there remains a mess for someone to sort out. The currently available phylogenetic data suggest the pyrotricha, velutina and lacrymabunda are being used interchangeably for several (more than 3) distinct taxa. I see at least 5 potential species even within USA sequences. 3 labelled lacrymabunda, 1 labelled velutina, and 1 with sequences labelled lacrymabunda or velutina (with a recent inat sequence I see). Even the Euro sequences of 'lacrymabunda' fall into three clades.
In summary I think the US use of the name L. velutina is dubious, and it is best treated as a synonym of L. lacrymabunda. It would be worth clarifying Smith's taxa in this group. I suspect better names for the various USA versions of 'L. velutina' and 'L. lacrymbunda' might be found amongst them.
All of this is from a rather superficial scan of the available information, so I'm happy to be corrected or updated.

Publicado por cooperj hace más de 1 año

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