Observation 208220: Amanita chrysoblema G.F. Atk.
When: 2015-06-29
Who: AJ (j7u)
No herbarium specimen

Proposed Names

55% (1)
Eye3 Eyes3
Recognized by sight

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

Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
Actually, its the opposite or nearly so.
By: R. E. Tulloss (ret)
2015-06-30 18:10:53 EDT (-0400)

Dr. Geml has been working on the muscarioid group at leat since his postdoc time in Alaska. Over the subsequent time (roughly 8 years or so), I have worked with him to get a broader and broader geographic sampling of muscaria-like specimens into his hands for sequencing. The results reported in his big 2008 paper have not been contradicted. The dominant muscaria-like taxon from southern Alaska to Central America has three color variants that apparently have been interbreeding rather recently: red, yellow-orange, and white. The question is what to call the species. If there is only one-white capped variant on the two sides of the U.S. Canadian border from Wisconsin to New York (or perhaps to the Atlantic Coast) then that white variant would fit the definition of A. chrysoblema and, presto, we have a name for the species. However, if there is only one white-capped muscarioid in the region, we face the ironic situation that it is impossible to prove that there are not two. We can only say that we have worked very hard and not yet found a second one. The questions is, “How hard does one have to work?” In fact, we are trying to wrap up the effort and really want to get the word out that we can really use samples of muscarioids that fit the morphological description of chrysoblema and that are white through and through. At some point, we will stop, propose a hypothesis and a name, and take our chances on whether our hypothesis will hold up in the future.

Right now, we can say that after so and so many years. The European (true) muscaria has three color variants but (using the available genetic data) forms on genetic grouping (clade) with a single common ancestor. The same is true of the North and Central American clade including all specimens that fit the definitions of muscaria subsp. flavivolata, muscaria var. guessowii, muscaria var. alba, or chrysoblema.

I get a lot “push” from folks who want a solution yesterday.

Very best,


Thanks Rod
By: AJ (j7u)
2015-06-30 13:54:06 EDT (-0400)

I’ve been operating under the assumption that A. muscaria var. guessowii is better called A. chrysoblema, but your comment seems to indicate they are in fact distinct species. Is that an accurate reading? I’ll keep my eyes out for truly white specimens and make sure to collect any if I happen across them.

The two younger specimens on the right in the third image…
By: R. E. Tulloss (ret)
2015-06-30 09:18:20 EDT (-0400)

have some yellow in the cap pigment I think.

Based on several sources, as well as the locality at which the type of chrysoblema was found (Michigan), I think that the most likely region in which a pure white (through and through) specimen might be found would be along the two sides of the U.S. Canadian border from New York to Wisconsin.

I have posted on MO and elsewhere that we have been seeking a white species that could be called chrysoblema and DOES NOT have the same DNA as all the white, yellow, and red specimens of the North American (non-muscaria) “muscarioid.” Dr. Geml and I have been at this every year since around 2007. We locate so few white specimens that it has been a bit frustrating. Our sample size of collections with white caps is very small (from memory I’d say “three” or so, certainly less than half a dozen). And in those few cases, we don’t know for sure that the material was entirely white (inside and out).

Very best,


I did not check under the surface
By: AJ (j7u)
2015-06-30 07:39:22 EDT (-0400)

I will go back this evening and collect specimens.

I am not contesting your determination with this question.
By: R. E. Tulloss (ret)
2015-06-30 00:21:18 EDT (-0400)

Did you cut any of this material in half to see what colors (if any) were in the cap below the surface of the cap’s skin?

I have been seeking material of chrysoblema with no yellow at all within the cap (i.e., below the surface of the cap’s skin).

If such material can be found, I am hoping to obtained dried specimens for genetic studies in collaboration with Dr. Jozsef Geml.

Very best,

Rod Tulloss

Created: 2015-06-29 22:41:07 EDT (-0400)
Last modified: 2015-07-07 19:36:45 EDT (-0400)
Viewed: 51 times, last viewed: 2016-10-21 10:48:16 EDT (-0400)
Show Log