Observation 189490: Amanita virosiformis (Murrill) Murrill
When: 2014-09-07
No herbarium specimen

Notes: The Top BLAST match was Amanita cf. virosa Montoya (sequence size was 245, 84% max identity):


Habitat- sandy soil, oak and pine woods
Spore print- whitish cream
Spores- 11.62-15.77×4.15-4.98 microns
Stipe- 6.0-9.0×1.0cm

Proposed Names

54% (1)
Eye3 Eyes3
Used references: http://www.amanitaceae.org?Amanita%20virosiformis
Mushrooms of the Midwest (M. Kuo & A. Methven):
North American Mushrooms a Field Guide To Edible and Inedible Fungi (O. & H. Miller)
Based on microscopic features

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

Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
Good evening, Kat. … EDITed
By: R. E. Tulloss (ret)
2014-12-28 23:02:48 CST (-0500)

In the technical descriptions on www.amanitaceae.org, the order of description of the elements of the stipe is (1) stipe description above the bulb excluding veils, (2) bulb excluding universal veil, (3) context, (4) partial veil, (5) universal veil.

This is the standard approach that I’ve developed and used over the last 36 (roughly) years. It’s a divide and conquer approach, set up so that comparisons between species are easier for a reader to make.

Except for item (1), the descriptions of parts begin with the name of the relevant part in italic type. The idea is to help the reader find the start of the description of a specific part in a long overall description of the stipe.

The data you were looking for is here:

…; universal veil as membranous to submembranous, limbate volva, torn into irregular lobes, smooth surfaced or impregnated with sand, white with occasional reddish or reddish brown stains, sometimes a pinkish tint on the interior surface, rarely(?) “bruising pinkish” (Murrill, regarding F17658), thin (less than 1 mm thick), upstanding at first and separated from the stipe barely (often with no evidence of limbus internus) or (less often) by width of complete, or rounded remnant of, limbus internus, adnate for about half to two-thirds of limb height, not clearly having an internal layer; height from highest tip of limb to bottom of bulb 33 – 62 mm (Beardslee: free limb 20 – 40 mm long).

The upshot is that there is a very pronounced, upstanding volval limb present in cylindrispora.

Unfortunately, your problem is not yet resolved.

Very best,


By: katwerner89
2014-12-28 21:17:06 CST (-0500)

I keyed Amanita cylindrispora backwards on mushroomexpert.com and found I that it did not match mine because in the key leading up to A. cylindrispora I would have to choose “Stem base without a sack-like volva” and mine does have a sac-like volva. The description on http://www.amanitaceae.org/?Amanita%20cylindrispora does not say that directly it says “bulb 23 – 34 × 13 – 23 mm (Beardslee: bulb 50 – 70 mm long), rounded below (subclavate) to napiform to very slenderly fusiform to subfusiform, subradicating to radicating, occasionally doglegged, with white mycelium at base”. I guess you really have to know your terminology for this one! But hey, I learned something new!

I’m not sure whether you will get a reaction to KOH from dried material.
By: R. E. Tulloss (ret)
2014-11-26 09:19:37 CST (-0500)

I’ll try contacting you through MO’s email function. If you’d like to lay out what you know and what your problems are, I’m interested in helping you solve this one.

Very best,


This a toughy…
By: katwerner89
2014-11-25 23:58:44 CST (-0500)

Yes, the soil is pretty sandy. It in my yard which is next to a wooded sand dune (mainly oak, pine and sassafras).

I’ll have to try the KOH next week but, would it still react the same on a dried specimen?

A.cylindrispora or A. virosiformis sound the most likely, but some things just don’t line up. I dont know but this one is sure giving me a lot of trouble!

It’s rather unusual to find any of the things I’ve suggested in Indiana.
By: R. E. Tulloss (ret)
2014-11-25 15:12:43 CST (-0500)

It looks like the mushroom was in dark sand. I see that you’re not very distant from a lake shore area.

Did you try a drop of KOH on the cap?

Very best,


Looks like 2/3 of the stipe was in the soil.
By: R. E. Tulloss (ret)
2014-11-25 15:06:50 CST (-0500)

Is that correct?

If so, try


in section Lepidella.

Very best,


It’s either in section Phalloideae or is …
By: R. E. Tulloss (ret)
2014-11-25 14:57:35 CST (-0500)

one of the limbate species in section Lepidella.

The extremely narrow spores are the clue.

For links to descriptions for the latter:


For the former, try


(and my apologies for the crumby picture…I’ve only found the species once).

Let me know how it goes.

Very best,


Created: 2014-11-25 13:58:05 CST (-0500)
Last modified: 2014-12-28 20:32:20 CST (-0500)
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