Observation 8235: Amanita flavorubens (Berk. & Mont.) Sacc.
When: 2008-07-02
Herbarium specimen reported

Notes: Volva is bright yellow, floccose. No part of the fruiting body discolored when bruised.

Proposed Names

8% (3)
Recognized by sight
Based on microscopic features
61% (3)
Recognized by sight: See comments below.

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

Eye3 = Observer’s choice
Eyes3 = Current consensus


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Can we..
By: Erlon (Herbert Baker)
2011-06-10 12:50:06 MDT (-0600)

..assume that the reticle has been properly calibrated with a stage micrometer?

Thanks for checking the spores!
By: R. E. Tulloss (ret)
2008-08-27 11:12:28 MDT (-0600)

OK. average spore was 8 × 5. This means the average length/width was somewhere around 1.6. This is too narrow for A. flavoconia. The spores are too small for A. flavorubens. Goldilocks would now look for something that is “just right.” I direct your attention to species 36 in sect. Validae on the New Jersey Pine Barrens checklist/picturebook page. The mushrooms depicted are a little browner than those in your pictures, but my picture includes specimens in which the cap has barely begun to get to full expansion. I think this species offers the best match to your pictures and to your spore measurments. In my notation bold L is average length for one specimen and bold L’ is average length for all the spores I measured. Bold W and bold W’ are equal to the analogous values of width averages. Bold Q and bold Q’ are the same for the average length/width quotient values. At the top of the checklist page, the first link will take you to a set of definitions that include the above and also explain how the ranges of numbers are presented. For the checklist page, look here.

The start of the information on sect. Validae is here.

What do you think?

Now we could ask Nathan to make “species 36” an acceptable species name entry; or we could just be happy with “sp.”; or I could make up a provisional name. I’m running out of time to prepare for driving to McCall, Idaho; I pass on the provisional name for the moment. OR, maybe I’m just dead wrong about this ID; and the mushroom is something else altogether. :-)

Very best,


By: Brian Seitzman
2008-08-27 09:58:24 MDT (-0600)

Hi Rod,

The spores on this specimen were an average 8×5 microns.

Bulb shape needs consideration…
By: R. E. Tulloss (ret)
2008-08-27 09:29:46 MDT (-0600)

The bulb on flavoconia has rounded “shoulders”, but is usually somewhat abrupt and not ovoid. I have never seen rings of volva around the base of a flavoconia stipe. I’m fairly certain that I see pinkish staining of the mushroom itself. There is something about the stature of the mushroom that suggests that if it is flavorubens it is depauperate. Also, the brownish tint in the center of the cap seems a little off for both of the taxa mentioned above. I’d go for Amanita sect. Validae (where rubescens, flavorubens, flavoconia, et al. belong). I think the only taxon of which I know that looks a bit like this species is the unnamed “sp. 39” of the NJ Pine Barrens checklist.

That’s about the size of it. Measuring spores (remember, lateral view only) of the dried specimen should tell you if “sp. 39” is a possibility.

Very best,


is that slight amount of red staining really significant?
By: Debbie Viess (amanitarita)
2008-08-26 09:16:39 MDT (-0600)

there appears to be quite a bit of potentially red staining forest debris in the photo…couldn’t that have caused the slight red color at the base? and is the fracturing of the mushroom base really significant enough to think that it is an undescribed sp., or could it just be individual variation plus environmental causes?

Usually flavoconia does not show redstaining at the stipe base…
By: R. E. Tulloss (ret)
2008-08-25 10:40:56 MDT (-0600)

It seems to me that there is pretty clearly reddish staining on the bulb and lower stipe.

Usually Amanita flavoconia does not show redstaining at the stipe base; nor does it have volval material is broken rings above the bulb. It seems to me that these images may depict an undersized A. flavorubens or an undescribed species. You might try measuring spores in your herbarium specimen and comparing the information to the detailed spore data provided on the NJ Pinebarrens checklist/picturebook of the Amanita Studies site.

Very best,


Created: 2008-07-05 05:55:11 MDT (-0600)
Last modified: 2013-10-15 00:46:57 MDT (-0600)
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