Observation 14622: Amanita muscaria var. “formosa” sensu Thiers
When: 2008-11-19
Herbarium specimen reported

Notes: From the color, I initially was going to call these A. gemmata. Not so sure now. They look like a var. of Amanita muscaria. The spores look almost globose at around 8.0 +/- 0.5 microns. They were growing where there were mostly Sitka spruce.

Proposed Names

47% (4)
Recognized by sight
57% (5)
Recognized by sight: The western version of the all yellow muscaria.
Used references: Thiers, 1982. Agaricales of California.
3% (4)
Recognized by sight: Probably a species of its own, within the A. muscaria subsp. muscaria clad.
40% (6)
Recognized by sight: one color morph of commonly encountered western species.
46% (2)
Recognized by sight

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

Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
I have gone back and looked at the “big tree” in the 2008 …
By: R. E. Tulloss (ret)
2015-10-18 07:36:53 PDT (-0700)

paper on muscarioids by Jozsef Geml et al.—-

Geml, J., R. E. Tulloss, G. A. Laursen, N. A. Sazanova and D. L. Taylor. 2008. Evidence for strong inter- and intracontinental phylogeographic structure in Amanita muscaria, a wind-dispersed ectomycorrhizal basidiomycete. Molec. Phylog. Evol. 48: 694-701

In that big tree, Clade I corresponds to the North American dominant muscarioid (with color variants); Clade III corresponds to A. regalis; Clade II corresponds to the Eurasian and Alaskan (true) A. muscaria (with color variants), Clade IV corresponds to A. persicina; etc.

[The WAO website includes GenBank numbers for sequences from my herbarium that were used in the tree. This may provide some help ti interested persons tracking current names for species corresponding to clades in the tree. In my usage, my herbarium numbers have a dash after the first three digits (e.g., 065-9 or 237-10), this dash was not shown in labels on the tree branches in the above cited paper.]

Where my material was used in the Geml et al. research, I know what color the cap was. My material that was originally called “muscaria var. formosa sensu Thiers” falls in Clade II. Hence, it is genetically closest to the Eurasian/Alaskan A. muscaria.

Very best,


The usual depiction is duller than the yellow of the eastern clade.
By: R. E. Tulloss (ret)
2015-10-17 22:34:04 PDT (-0700)

But we are talking about things I was working on with great focus in the period 2006-2008. I would have to reconstruct any subtle points. That’s why I was hoping that the comments would still be accessible.

Very best,


Hmm * edited
By: Erlon (Herbert Baker)
2015-10-17 17:51:39 PDT (-0700)

I don’t believe we did; or perhaps I misunderstood your previous comments. So the western yellow form of A. muscaria var. “formosa” sensu Thiers from the European clade is a brighter solid yellow the like eastern guessowii; and the yellow form of A. muscaria subsp. flavivolvata in the west is duller as shown here?? If that is the case than perhaps some of the names currently listed on MO as A. muscaria var. "formosa Thiers are incorrect. I’m not sure I can differentiate between the two, can you show me an example? Most all of the western solid yellow caps, on MO, are going under the name “formosa” and appear duller yellow than the eastern version. Thank you.

It’s not the same bright yellow that we see in the east.
By: R. E. Tulloss (ret)
2015-10-17 15:34:54 PDT (-0700)

It’s more like what is shown in this observation.

It seems to me we covered this ground in lengthy observation a couple of years ago…maybe more than that. I hope those comments are still available on this site. I think they are.

Very best,


Hi, Rod.
By: Erlon (Herbert Baker)
2015-10-17 13:06:14 PDT (-0700)

That’s interesting. So you are saying a solid yellow form of A. muscaria subsp. flavivolvata also exists on the west coast along with the solid yellow form from the European muscaria clade? Do you have any examples of this solid yellow form from the region? Thanks!

Thanks Rod,
By: Ron Pastorino (Ronpast)
2015-10-13 17:30:19 PDT (-0700)

I’ll keep my eyes open to see if some fresh material might show up this year.

I did a sporograph comparison to the taxa in the provisional…
By: R. E. Tulloss (ret)
2015-10-13 08:25:01 PDT (-0700)

stirps Muscaria, and the new spore measurements are much broader than any recorded for any other species. This could be the result of immaturity leading to production of giant spores on Ron’s material. Our comparison of red European muscaria spores to spores of the red (flavivolvata) color variant of the “dominant North American muscarioid” is based on range and average utilizing hundreds of spore measurements (nearly 700 in the first case and nearly 1,000 in the second case). With that amount of data differences can be seen. While I very often can separate the two species using spore measurements, there are cases in which it may not be possible (very young material, very old material, material that suffered from various environmental impact(s), etc.).

All of the yellowish muscarioid taxa of Oregon, Washington, or British Columbia that have been sequenced by Dr. Geml since about 2006 have fallen into the Amanita muscaria clade or the clade representing the “dominant North American muscarioid.” The issue of the different cap colors not representing separate species or separate subspecific taxa has been discussed repeatedly on MO.

The bottom line is that I don’t think we can resolve this issue from the information available.

Very best,


Thank your, Ron.
By: R. E. Tulloss (ret)
2015-10-13 06:34:18 PDT (-0700)

Thanks very much.

The length of the spores is now consistent w/ a muscarioid amanita; however, the Q value is rather low. I’ll look into this.

Very best,


Apparently my initial measurements in 2008
By: Ron Pastorino (Ronpast)
2015-10-12 17:37:40 PDT (-0700)

were VERY crude.
This time I get; 9.0-12.9 X 8.1-10.4 microns, subglobose to broadly ellipsoid.
Q(range) = 1.10-1.30(1.41)
Q(avg) = 1.19(1.21)
The spores seem thin walled and fragile but the two photos added appeared to be representative of mature spores.

Just realized I had saved these.
By: Ron Pastorino (Ronpast)
2015-10-12 15:44:17 PDT (-0700)

They appear to be a little soft, but I’ll try to recheck the spores to see if I can verify my crude 2008 measurements.

No new spore data from me.
By: Ron Pastorino (Ronpast)
2015-10-12 14:46:14 PDT (-0700)

So Rod, what would you say would be the most logical current designation for this collection, without resorting to the safest, i.e., “Amanita”.

This observation just came up in my email…first time in a while.
By: R. E. Tulloss (ret)
2015-10-12 12:42:16 PDT (-0700)

Ron’s description of the spores is something I hadn’t noticed before.

The spore size and shape would eliminate anything close to the muscarioid’s previously under discussion.

Is there new data on the spores?

Very best,


Re-read the first part
By: Erlon (Herbert Baker)
2015-10-12 09:50:27 PDT (-0700)

“This subspecies apparently contains the same toxins as Amanita muscaria subsp. muscaria of Europe, northern Asia, and far northwestern North America (western Alaska with some yellow-capped populations in southwestern Canada and into the northwestern US).”

Clearly he is referring to the PNW yellow capped species as A. muscaria, not A. muscaria subsp. flavivolvata.

Best wishes,


I did.
By: Debbie Viess (amanitarita)
2015-10-12 09:35:21 PDT (-0700)

If you go to Rod’s site, he calls our western muscaria, regardless of cap color, flavivolvata. I have read his and Geml’s 2007 paper. I am aware that color alone is probably insufficient to create a subspecies, but that our western muscaria is distinct from eastern forms. therefore it is useful to use our most familiar local designation, until we come up with something better.

Here’s a quote from his webpage on flavivolvata:

“This subspecies apparently contains the same toxins as Amanita muscaria subsp. muscaria of Europe, northern Asia, and far northwestern North America (western Alaska with some yellow-capped populations in southwestern Canada and into the northwestern US). Amanita muscaria subsp. flavivolvata occurs from lower altitudes in Alaska, through southwestern Canada, through the Pacific coastal regions of the US, through the Sierra Nevada and the Rocky Mountains to the “mountain islands” of the desert Southwest in the US and at least as far south as the montane oak forests of Costa Rica. "

Index Fungorum currently has all muscaria varieties back under a simple Amanita muscaria designation. I don’t believe that is correct, either.

I think the dust hasn’t quite settled on Amanita muscaria and what we should call all of the many eco-distinct varieties.

By: Erlon (Herbert Baker)
2015-10-12 08:51:34 PDT (-0700)

Please read the previous comments.

I have found yellow muscaria on Mt. Tam,
By: Debbie Viess (amanitarita)
2015-10-12 08:26:51 PDT (-0700)

which is in Marin county, northern Bay Area, fairly centrally located in our state. Since it is merely a color variant of muscaria var. flavivolvata, we should see it popping up here and there in the West. It is certainly rare to the south of the PNW, but does occasionally occur.

By: Darvin DeShazer (darv)
2011-04-12 19:23:00 PDT (-0700)

It’s also found in the north western corner of California, at least from Eureka to the Oregon boarder.

All yellow PNW form
By: Erlon (Herbert Baker)
2011-03-22 19:07:18 PDT (-0700)

The all yellow PNW form may represent its own species, represented by clad II/A in Geml’s cladogram. The range of this species appears to be from the south-eastern coast of Alaska to Oregon.

I think that Herbert’s proposal is probably supported by recent DNA work by Geml.
By: R. E. Tulloss (ret)
2009-09-20 12:31:55 PDT (-0700)

I.e., in the PNW, the “muscaria var. formosa” does not form a separate clade from A. muscaria as far as is presently known. It is the “PNW yellow variant” of A. muscaria according to the best present understanding.


Created: 2008-11-25 16:51:06 PST (-0800)
Last modified: 2015-10-18 08:24:30 PDT (-0700)
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