Observation 57796: Amanita amerirubescens Tulloss nom. prov.

When: 2010-10-30

Collection location: Hickory Run State Park, Pennsylvania, USA [Click for map]

Who: Dave W (Dave W)

Specimen available

Found growing on a lwan nearby Norway Spruce. Matches amerirubescens in all respects, except there was virtually no reddish staining. Stipe darkened slightly with handling over time.


First pic after spore shot… filamentous hypha?
First pic after spore shot… filamentous hypha?
First pic after spore shot… filamentous hypha?
First pic after spore shot… filamentous hypha?

Proposed Names

42% (4)
Eye3 Eyes3
Recognized by sight: Gray volval patches on non striate cap. Club shaped ringed stipe with no basal collar.
Based on chemical features: Spores amyloid.

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

Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
By: Erlon (Herbert Baker)
2014-07-18 12:28:54 PDT (-0700)

Can you could take a look at some of the other observations I have suggested sp-amerirubescens07 for? The grey volval remnants at the base could be a factor for delineation. You’ve suggested that looking at it through a microscope may help tell if it’s a true grey. Do any of the other unnamed rubescent taxa that you’ve had the chance to examine exhibit a natural grey as opposed to becoming grey in age? Thanks!

Edit. I see some slight rubescent coloring on the stipe in the second photo.

I appreciate your thank you.
By: R. E. Tulloss (ret)
2014-07-18 11:32:44 PDT (-0700)

No hindrance, I assure you.

Very best,


There are two reasons at least. EDITED TWICE
By: R. E. Tulloss (ret)
2014-07-18 11:26:30 PDT (-0700)

The image for this observation shows no staining, and David’s text says he saw none; hence, we have no proof that this species is rubescent. Secondly, the warts on David’s collection of sp-amerirubescens07 are pallid and separated into thick warts that cluster to one side (in David’s photo) at the base of the stem, while, in the present case, the volva appears to take the form of a layer of gray powder encircling the bulb in a band near the base of the stem. That’s a pretty significant difference for me.

Very best,


By: Erlon (Herbert Baker)
2014-07-18 09:22:42 PDT (-0700)

Rod, Why give it a ‘doubtful’ vote? Is there anything to suggest this is not the same species. I could understand a ‘could be’.

By: Erlon (Herbert Baker)
2014-07-18 08:35:11 PDT (-0700)

I only suggested it so in the future we can compare collections with true grey volval remnants. Thanks for clarifying what you know so far. I hope you find my suggestions helpful and not a hindrance. Thank you.

A cautionary note.
By: R. E. Tulloss (ret)
2014-07-18 05:52:58 PDT (-0700)

At the moment, we can only recognize “sp-amerirubescens07” genetically.

I can see from Eric’s and David’s photos on the two observations to which I posted yesterday, that the cap color is variable (probably due to age, bruising, drying, etc.) The dark volva in some pictures could be due to the genetics of the organism itself, or it could be due to dark hyphae of a foreign fungus in the volva. Or there could be another cause. We don’t know enough yet.

And rubescent staining is persent in both of the known collections of “sp-amerirubescens07.”

Very best,


A cautionary note.
By: R. E. Tulloss (ret)
2014-07-18 05:52:30 PDT (-0700)

At the moment, we can only recognize “sp-amerirubescens07” genetically.

I can see from Eric’s and David’s photos on the two observations to which I posted yesterday, that the cap color is variable (probably due to age, bruising, drying, etc.) The dark volva in some pictures could be due to the genetics of the organism itself, or it could be due to dark hyphae of a foreign fungus in the volva. Or there could be another cause. We don’t know enough yet.

And rubescent staining is persent in both of the known collections of “sp-amerirubescens07.”

Very best,


I was recently thinking about a past discussion…
By: Dave W (Dave W)
2014-07-17 21:17:12 PDT (-0700)

when Rod explained some basics of scoping dehydrated material… except I couldn’t recall the context or the obs #.

Aside from what I have learned (past 5 years) about scoping fungi, I have no background in using a microscope. I see that the NEMF 2014 Ristich event in Maine offers an intermediate microscope workshop, which I’ll register for.

Another variety of Amanita to keep in the back of my mind. I visit this collection location occasionally.

You got ’em and, I think, a bonus example of a vascular hypha
By: R. E. Tulloss (ret)
2010-11-08 18:40:34 PST (-0800)

Persistent fellow! That you are. And you are rewarded this time.

Images 119480-119482 are indeed linearly ordered cells from the universal veil. In fact some are clearly paired in a “chain”.

If the second and third of these shots are examined at the largest size available, one can see that the hypha that is darker than other hyphae and is seen wiggling its way from lower right to upper left (approximately) is a probably a vascular hypha.

In the second photograph of the inflated cells, look at the diagonal, dark hypha in its well-focused segment to the left of the arrowhead and below the arrowhead. In this area you can see a distinct yellowish tint and places where the hypha appears to have “knobs” or “bumps” on it. These “knobs” or “bumps” are places where the poorly soluble or insoluble contents of the vascular hyphae have leaked into the mounting liquid. The color and the bumps are very typical of the vascular hyphae in an Amanita.

Nice going, David. Thanks for keeping at it.

The last image (119483) shows air bubbles gathered on a bit of detritus.


I scraped some material from
By: Dave W (Dave W)
2010-11-08 17:43:56 PST (-0800)

the cap of the button specimen. I think I may have found some colorless inflated cells. Last image shows what may be wtaer droplets created when the material/slide was humidified. Three pics before last one show the “balloon clusters” which, for the time being, I suppose are inflated cells.

By: R. E. Tulloss (ret)
2010-11-03 06:07:49 PDT (-0700)

In order of appearance, these are my interpretations:

1. basic fungal hypha (could be from the amanita)

2. same as #1 — except this one is split down one side and the wall of the hypha has been laid out flat except at the ends of the segment. (could be from the amanita)

3. pigmented (dark), thick-walled hypha (not Amanita tissue)

4. same as #3, showing branching (not Amanita tissue)

I would suggest that you may need a larger piece of material from a cap wart in order to see the inflated cells.


Four micro shots
By: Dave W (Dave W)
2010-11-02 19:06:33 PDT (-0700)

after spore pic. Comments underneath pics do not correlate with photos. I think the first pic undermeath the spore shot may be a filamentous hypha. And maybe the second in a vascular hypha… although I don’t know… maybe it’s just a piece of debris. I think the third and fourth shots show be filamantous hyphae.

size of bowl…
By: R. E. Tulloss (ret)
2010-11-02 11:23:57 PDT (-0700)


You’ll need to take the size of the bowl into account. A small space reaches 100% relative humidity faster than a large space…given both start at the same ambient relative humidity. That’s the only thing that I can see is different in the case you describe.

Looking at the descriptions for which I gave urls below, I remembered that the relative amount of inflated cells is larger in the warts on the cap surface and the cells are often larger there also. You may want to take the lower (not messed up and gelatinized) part of a wart to look at…or just take a cross section of a wart or something close to that…. I’m just saying get fresher volval material away from the upper surface of a wart. :-)

Very best,


To hydrate the material
By: Dave W (Dave W)
2010-11-02 10:04:48 PDT (-0700)

for study, it sounds like I may simply place a pedestal inside a shallow bowl, put the slide + material onto the pedestal, surround the lower half of the pedestal with water, and cover the top of the bowl with a piece of flat plastic or carboard.

I’ve got 4% KOH to mount the material.

Cells of volva
By: R. E. Tulloss (ret)
2010-11-02 06:19:04 PDT (-0700)

OK, Dave.

This is not complex. Gently scrape some of the volval material from the stipe base onto a slide. Place the slide in a small closed space with an open container of water to humidify the material.

Those old plastic boxes with a fold back lid that photograph slides used to come in in ancient times have a pair of low dividers that can hold the slide up. Putting a thin layer of water in the bottom of the box will produce enough moisture in about 2 minutes or so. Longer exposure may help a bit. Volval material is easier to inflate than gill tissue (for example).

A more “standard” way of stating the lab procedure would be to place the dry slide on a small object to keep it above water level in a petri dish with watter in the bottom. Then put a cover on the petri dish.

A quick and dirty way to make it easy to humidify the specimen is to put a drop of alcohol (rubbing alcohol will do, don’t waste the booze) on the specimen. In either case you’re trying to make it easier for water to enter the specimen (reducing surface tension) without trapping so many bubbles that you really can’t see the detail.

Now add the mounting liquid. You want to see color in this case, so don’t add a stain. A dilute basic solution in water (KOH or ammonium hydroxide ) will rehydrate the tissues for you to view. Gentle heating can drive out bubbles that may form under the cover slip. Material can be spread out by gently allowing a pencil point to drop a short distance (about a quarter inch would be my guesstimate) onto the cover slip. Pressing hard or repeating the above process too much can bust up the inflated cells.

The volval will have some detritus mixed in, foreign spores and foreign hyphae are not uncommon. Deterioration may be evident at the survace of the volva. Of course, this part of the mushroom has had the longest exposure to the nasty outside world. As mentioned in the handbook from the Kerhonkson workshop, there are three cell types in the volva of an Amanita: undifferentiated, filamentous hyphae (run of the mill, uncolored or [infrequently] yellowish, rather thin, with obvious segmentation [septa]); inflated (balloon-like) cells that are terminal on the run of the mill hyphae either as single balloons or in chains of same; and vascular hyphae (unsegmented [no septa], more sinuous or irregular than regular hyphae, appearing to have a refractive internal substance, leaking insoluble material [makes the vascular hyphae appear to have occasional hemispheric bumps on them]). Anything else is not Amanita tissue. Bug parts, leaf fragments, algal cells, sand crystals, etc. are par for the course on surfaces.

More of an idea of what you may see will be found in the “universal veil” data field of the technical tabs for these taxon pages of www.amanitaceae.org:


So far as I have observed, rubescens, novinupta, and amerirubescens (nom. prov.) have the volva colored by staining of damaged cells and by decay. In the latter case, material dried at a very early stage of development may have some inflated cells that are distinctly yellow. Otherwise, in the above taxa, you should find that the inflated cells of the volva that seem unbroken are colorless. These cells are plenty big enough to see easily at 400X.

By the way you will easily find yellow inflated cells in the volvas of A. flavoconia or A. flavorubens.

Colored cells from the volva of A. brunneolocularis (for example) are distinctly and evenly brownish. Light passes through the color, but the color is very distinct. Color may be in some percent of the inflated cells, but not all.

In your material, if the color of some inflated cells is gray rather than brown, this should be noted and may be relevant to determination of species for your material.

Your thought concerning the impact of temperature on the volva color (or the lack of staining) seems worthy of some research.

If the above is not adequate, let me know about anything further that is needed.

I’m curious to hear more of what you may find.

Very best,


I’m wondering if the lack of staining
By: Dave W (Dave W)
2010-11-02 04:45:36 PDT (-0700)

and the gray tones (especially on the edge of the ring) may be due to the mushrooms developing at a time when the nighttime temps dropped below freezing?

I’ll need a little coaching as to how to view the cells on the base of the button. Both specimens have been dehydrated. I use a max 400x scope.

a little unusual?
By: R. E. Tulloss (ret)
2010-11-01 17:50:43 PDT (-0700)

The annulus looks gray; and the volva on the base of the stem in the button is already gray. That suggests that the volva may have had pigmented cells in it from the get go. Dave see if there are brownish inflated cells in the universal veil on the button’s stem base. I’m curious about the non-staining, also.

Very best,


Created: 2010-11-01 17:01:31 PDT (-0700)
Last modified: 2014-07-18 12:30:34 PDT (-0700)
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