Observation 213333: Amanita farinosa Schwein.

This was found in mostly deciduous woodland. It was distinctive in it’s decay that is why I collected it. I’m not 100% certain I have the right microscopy matched up with the right mushroom. I think so as I used Melzer’s on this and not the other sect. Vagninatae specimen I may have looked at under the scope this day. I would love confirmation if possible.

Proposed Names

28% (1)
Recognized by sight: A little elderly Amanita fuscozonata type? No partial veil present when collected.
55% (1)
Recognized by sight

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Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
By: Athena (Apfelmusser)
2015-11-20 12:47:39 PST (-0800)


We’ve received your package, and the mushrooms have been accessioned into RET’s herbarium.

Thank you!

There is no need to send separate shipments.
By: R. E. Tulloss (ret)
2015-08-21 08:02:50 PDT (-0700)

I really appreciate your support of our research.

Thank you,


In Amanita there are taxa which regularly produce some two-spored basidia…
By: R. E. Tulloss (ret)
2015-08-21 06:37:02 PDT (-0700)

…at the start of sporulation. This results in spores of approximately double the volume. In such spores you can estimate the expansion in spore length and width by multiply your “typical” spore range numbers by the cube root of two (1.25992…). Hence, if 10.5 um is the length of a sample spore of double normal volume, a spore of normal volume might be expected to have length of about 8.3 um (=10.5 divided by 1.25992). It is then plausible that, given the range of spore length recorded for farinosa, you might find a “giant spore” or even several with length around 10.5 um on some fruiting bodies of the species.

Very best,


Sure, I will include it.
By: Garrett Taylor (cappy)
2015-08-21 04:38:58 PDT (-0700)

I was trying to get you a couple before I send this out, but may just send these two anyhow.

Might I take a look at the specimen or part of it?
By: R. E. Tulloss (ret)
2015-08-20 20:57:57 PDT (-0700)


Spore measurements
By: Garrett Taylor (cappy)
2015-08-20 19:21:29 PDT (-0700)

The spores in IMG_1248_1.jpg seem to be in line with the measurements you provided, however I don’t know if their orientation was off. All the spores that I measured were in the range, but quite a few of the larger ones were 6.5-7µm X 10.5µm though, and perhaps on the outside of what is possible Q-wise.

If the images of spores depict typical spores (and not just …
By: R. E. Tulloss (ret)
2015-08-20 14:10:17 PDT (-0700)

… the most narrow) then the spores are too narrow for farinosa.

An excerpt from the WAO A. farinosa page follows:

[180/9/9] (6.0-) 6.5 – 8.5 (-10.5) × (5.2-) 5.5 – 7.0 (-9.0) µm, (… Q = (1.03-) 1.08 – 1.37 (-1.47) …) ….

Do you have measurements of the spores you photographed? Amanita farinosa spores are among the smallest of any amanita in eastern North America.

Very best,


Created: 2015-08-20 07:50:03 PDT (-0700)
Last modified: 2018-01-05 19:48:42 PST (-0800)
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