Not so sure I understand Dr. Tulloss. If this yellow fly agaric from Ohio is not A. amerimuscaria, then what is it? Something branching off from amerimuscaria, or is it something different altogether? Is the data sufficient to make a determination?

Most of the Ohio muscaria are found under pine, including the one in this observation, but I know of one patch that lives under maple and hickory with no pines for miles. Ecological specialization can lead to reproductive isolation. Are you and Dr. Geml looking at ecological data when describing the new species?

If the yellow form turns out to be its own species or variation, would that negate the need for the yellow color to be part of the original flavivolvata description and the basis for creating A. amerimuscaria nom. prov. instead of simply raising subsp. flavivolvata to species rank?
Thank you.

Rod said.. “The gene sequences of the white and yellow populations are scattered among the gene sequences of red populations. This suggests that A. muscaria var. guessowii is a taxonomic synonym of “A. amerimuscaria.””

But the yellow form of A. amerimuscaria(A. muscaria var. guessowii) is geographically disjunct from the red form.
Shouldn’t the yellow form of amerimuscaria at least get var. or f. status?
Is it correct to create species concepts based solely on DNA?

Thank you Rod :)

Your explanations are always very informative. I think I understand what’s going on now.

“A. muscaria var. formosa sensu Persoon” has a dubius referent, and is therefor NOT a good name. Persoon did not travel to America, so it seems unlikely that he was referring to yellow fly agarics from North America. There are no photos of Persoon’s mushroom, and the herbarium specimen is either missing or degraded to the point of being useless, so it is not possible to establish the referent by pointing to a type specimen. Its hard to say what kind of mushroom Persoon was referring to when he used the name “A. muscaria var. formosa”. The name’s original referent and meaning cannot be established; it is nomen dubium.

Both micro and molecular morphology suggest that the fly agarics of Europe and America are two different species. Furthermore, micro and molecular morphological comparisons also suggest that the different colored fly agarics in America are all the same species. A. muscaria is the species rank name for fly agarics in Europe. Similar mushrooms in America should not be given varietal names of A. muscaria, because populations on the two continents actually represent two different species. A different species-rank epithet is required for the American fly agarics.

“Amanita muscaria var. guessowii” is a better name than var formosa of Persoon, because the referent is clearly the yellow fly agaric of North America. No dubious referents here. On the other hand, “Amanita muscaria var. guessowii” is not a good name, because it means something that is not the case, i.e., that the American and European mushrooms are varieties of the same species.

Here we have a case of co-extensive names with different meanings, an interesting problem for philosophers of language.

For similar reasons, straight up “A. muscaria” is also NOT a good name.

“A. muscaria group group” is a good name, but its broader scope of referent encompasses more than one species.

“A. amerimuscaria” appears to be the best name up there.

We all know this is the yellow fly agaric, but there is confusion about the ‘correct’ name. Names are correct or incorrect only in so far as convention deems them so. All the names above (with perhaps the exception of A. muscaria var formosa sensu Theirs) refer to this kind of mushroom. All the names are good names because they adequately pick out the specific kind of mushroom shown in the photos. None of the names are wrong or bad. Let the people vote and convention will decide what name will headline the observation.

“Amerimuscaria” has taken an early lead. This name evokes a geographic species concept that could lead to complications. Alaska is in America, but the mushrooms there appear to be the Eurasian variety. Furthermore, these appear to be morphologically distinct from other A. amerimuscaria. Why not get more specific and make it A. ohiomuscaria?

I’m surprised at the low rating given to var. formosa pers. This name is straight forward and descriptive, and it was coined by one of the founding fathers of mushroom taxonomy. A. muscaria var formosa is a fine name for this mushroom.