Observation 213343: Leucoagaricus Locq. ex Singer

When: 2015-08-15

Collection location: West St. Louis Co., Missouri, USA [Click for map]

Who: Judi T. (AvidAmateur)

No specimen available

A few fruiting in landscaped mulch bed under mature Eastern White Pines. Cap: 5 cm. Stem 6.5 cm X 5 mm. at apex, enlarging toward club-shaped base. Flesh solid white, bruising pale yellow when sliced. Obtained persile white spore print.


Copyright © 2015 Judi Thomas
Copyright © 2015 Judi Thomas
Copyright © 2015 Judi Thomas
Copyright © 2015 Judi Thomas
Copyright © 2015 Judi Thomas
Copyright © 2015 Judi Thomas
213343 01.jpg
Copyright © 2015 Brad Bomanz
For commercial use the copyright holder can be contacted through the Missouri Mycological Societys web site: http://www.momyco.org
213343 02.jpg
Copyright © 2015 Brad Bomanz
For commercial use the copyright holder can be contacted through the Missouri Mycological Society’s web site: http://www.momyco.org
213343 03.jpg
Copyright © 2015 Brad Bomanz
For commercial use the copyright holder can be contacted through the Missouri Mycological Society’s web site: http://www.momyco.org
213343 04.jpg
Copyright © 2015 Brad Bomanz
For commercial use the copyright holder can be contacted through the Missouri Mycological Society’s web site: http://www.momyco.org
213343 05.jpg
Copyright © 2015 Brad Bomanz
For commercial use the copyright holder can be contacted through the Missouri Mycological Society web site: http://momyco.org
213343 06.jpg
Copyright © 2015 Brad Bomanz.
For commercial use the copyright holder can be contacted through the Missouri Mycological Society’s web site: http://momyco.org
213343 07.jpg
Copyright © 2015 Brad Bomanz.
For commercial use the copyright holder can be contacted through the Missouri Mycological Society’s web site: http://momyco.org
213343 08.jpg
Copyright © 2015 Brad Bomanz.
For commercial use the copyright holder can be contacted through the Missouri Mycological Society’s web site: http://momyco.org

Proposed Names

-9% (2)
Recognized by sight
1% (7)
Recognized by sight
-3% (4)
Recognized by sight: See comment.
-36% (3)
Recognized by sight: Check to see if the spores are amyloid

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

Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
P.S. Thanks IG and Dave for helping me
By: Judi T. (AvidAmateur)
2015-08-28 12:40:14 CDT (-0400)

with directions on how to post so many additional photos.

Spore photos are uploaded so
By: Judi T. (AvidAmateur)
2015-08-28 12:39:05 CDT (-0400)

everyone can take a look and have a chance to stand by or revise their initial impressions in light of this new information. This was my first time to ever see spores under the microscope (fantastic – can’t wait to do it again!) so about all I can say is that they appear to be dextrinoid (reddish-brown) and we did not see any germ pores. I guess that rules out Amanita and possibly the L. leucothites. However, more experienced eyes may see something different. Photo with suffix 01 is in water only, photos 02-05 with oil immersion, and 06-08 with Melzer’s.

These don’t look like amanita spores…
By: I. G. Safonov (IGSafonov)
2015-08-28 12:25:08 CDT (-0400)

Dextrinoid, not amyloid; small size; unusual cellular contents.
Basically, this evidence is in line with the original difficulties in reliably placing these “amanitas” into any of the 7 sections.

Numbers of photos…
By: Dave W (Dave W)
2015-08-28 09:38:01 CDT (-0400)

you may add during a single add-photos session depends upon file size (pixels). I find that I may add 3 or 4 of my ~1 MB photos during a single addition session. If I want to add more photos than possible during one addition session, then after the first few are added, I access another session.

Just post the pix here…
By: I. G. Safonov (IGSafonov)
2015-08-27 23:55:25 CDT (-0400)

Try and see how many you can add — maybe there is no limit. IMO, keeping the photo documentation under the same obs is optimal.

Spore photos under magnification
By: Judi T. (AvidAmateur)
2015-08-27 21:28:29 CDT (-0400)

I met with Brad Bomanz, the Research Committee Chair of the Missouri Mycological Association, today and he very kindly took a series of 8 photos of the spores from this observation … with and without oil immersion and with Melzer’s reagent. I am not sure how many photos I can add to the already 5 or 6 on this ob. (what’s the max) or what might be the best way to link these new images to this observation, e.g. if I post just the spore photos as a separate observation and refer users to that one in the comments, what name would I use for the new ob? Does anyone have an opinion about the best way to link the new information to this existing observation?

Thanks again everyone! I’ll contact the one person I know who
By: Judi T. (AvidAmateur)
2015-08-23 21:03:57 CDT (-0400)

might be able to help me with the microscopy. I haven’t used a microscope since college microbiology (eons ago) and have only a vague recollection of how to do that. If and when I can accomplish the tests you suggested, I will — happily — update this observation. THNX for the help.

Well, as indicated by my votes…
By: Dave W (Dave W)
2015-08-23 20:15:44 CDT (-0400)

IMO it’s a tossup between Amanita and Leucoagaricus. Judi, I think you’re photo-documenting here is very good. Having a selection of different visible traits to observe makes this an interesting observation, as evidenced by the numbers of votes/comments. I agree, the suggestion that all of the mushrooms had rings that mysteriously disappeared seems like a stretch. But atmospheric conditions can produce weird results.

By: else
2015-08-23 18:12:46 CDT (-0400)

if there is a spore print and a microscope you can look at the spores (do it at high magnification, 100x with oil immersion), and look first what the shape is, secondly whether there is a germ pore (congo red to stain the spores comes in handy), and thirdly whether the spores react in Melzer’s reagent!

otherwise, we can keep guessing !

Well, folks: Before we agree to disagree let me put
By: Judi T. (AvidAmateur)
2015-08-23 16:29:43 CDT (-0400)

in my (admittedly novice) two-cents. Dave, I usually agree wholeheartedly with your observations and suggestions; however, I think it would be highly unlikely that the rings would disappear from ALL of the specimens I collected — even the freshest/youngest of the group — and without leaving even the faintest trace on any of the stems. What are the odds on that? Secondly, it is hard to put into words, but having looked at the many MO observations of L. leucothites several times and trying to reconcile their “look” with my specimens I keep coming back to my own sense that there is a difference — however subtle — that leaves me uneasy about calling my observation L. leucothites. I am by nature a detail-oriented (rather than global) thinker and some of the tiny, subtle differences (e.g., the broader flatter umbo of the L. leucothites) leave me with nagging doubts.

I don’t have any Melzer’s solution, but I will check with MOMS scientific director to see if he does and if we might be able to test the spores that I still have available from the spore print. If that fails to satisfy all concerned, I guess we are back to leaving this OB with a big question mark.

Thanks again, everyone, for your input, your helpful suggestions, and your attempts to help me identify this observation. As always I am most appreciative.

Initially, Leucoagaricus did not enter my mind…
By: Dave W (Dave W)
2015-08-22 22:34:08 CDT (-0400)

probably because I am used to seeing a collar-like ring on the stalk, and none of these show any signs of a ring.

Reading descriptions of L. leucothites, I see that the ring is known to disappear. So I think it’s reasonable to suppose that all of the mushrooms seen in this obs were born with a ring, for a period of time failed to mature normally, and then resumed growth after the partial veils had weakened their grips upon the stipes. This would also explain the appendiculate material clinging to the cap margins as pv remnants (a trait also seen within section Amanita of genus Amanita). Also, the material seen on the ground near the stipe base in the in-situ photo may also be uncharacteristically deposited pv material. Looking at photos online I see several examples of ringless L. leucothites with, instead, appendicuate material that may only be explained as coming form the pv.

As else suggested, other than the lack of rings, other observable traits match well with L. leucothites… bulbous stipe bases lacking universal veil deposits, pale yellow staining on the sectioned stipe context, caps without marginal striations.

Partial veil attachment
By: I. G. Safonov (IGSafonov)
2015-08-22 21:45:56 CDT (-0400)

It’s difficult to argue with Rod’s “rule of thumb thinking” pointing to sect. Validae as the spelled out logic makes perfect sense.
In the third pic from the top, however, the youngest/smallest fb has remnants of the PV attached to the cap margin in the “appendiculate fashion”. Rod, I understand this character is usually associated with amanitas from sect. Lepidella, but not sect. Validae. Is this right?
On an unrelated subject, the default thumbnail pic originally gave me a strong impression of the Death Cap…

Else, they sure are look-a-likes in many respects, aren’t they?
By: Judi T. (AvidAmateur)
2015-08-22 19:23:54 CDT (-0400)

I looked and looked, but no matter how hard I tried, I could not find a ring nor any sign one had ever been there. I do hate loose ends, like a genus without a species; but I have learned that sometimes that’s the best we can do. Thanks so much for looking at my observation and offering your insights.

reminds me most of Leucoagaricus leucothites, but without a ring
By: else
2015-08-22 14:43:46 CDT (-0400)

For me, but i admit immediately that i am biased towards the white-spored Agaricaceae, this is a Leucoagaricus leucothites which has lost its ring. Again microscopy should sort this out easily (dextrinoid spores with a small germ pore, abundant cheilocystidia, and no divergent lamella trama).

Thanks, Dr. T. and Dave, for your carefully considered
By: Judi T. (AvidAmateur)
2015-08-22 14:39:39 CDT (-0400)

opinions and comments re: this observation. My first impression when spotting these specimens was Amanita (they just had that “Amanita aura” as Arora calls it); but I could not get them to key out with any reliability. I appreciate knowing what they are not. Perhaps they will just have to remain one of the many unidentified Amanitas in the world for the time being. Again, thanks for your helpful comments.

Looking at the nearly rooting or rooting bulbs and the specimens with white …
By: R. E. Tulloss (ret)
2015-08-20 21:03:38 CDT (-0400)

… caps, I first think of sect. Lepidella; however, if these specimens represent a single species then it must have a yellow or yellow-orange cap at least at first; and this would eliminate sect. Lepidella. Possibly this cap fades with exposure and age or after a rain storm (like flavorubens, for example).

The longer short gills that I can distinguish seem not to be strictly truncate. There is no evidence of a striate cap margin at any stage of life. This information lowers the possibilities with regard to section Amanita.

The presence of a bulb at the stipe base eliminates sections Caesareae, Vaginatae, and Amidella. (For those who were in the NEMF2014 Amanita talk, this is a case of eccentric development of the basidiome in the primordium.)

There are remnants of a torn, membranous, white partial veil on the cap margins of several of the specimens.

There is no volval limb on the basal bulb of the stipe. This eliminates sect. Phalloideae.

My guess is that (if this is an Amanita) it would have amyloid spores and belong in the Validae…given the evidence listed above. That’s all “rule of thumb” thinking. Environmental factors may have played a role…making determination more difficult.

Very best,


From the second picture, if forced to guess, I think I would have said, …
By: R. E. Tulloss (ret)
2015-08-20 20:46:26 CDT (-0400)


Thanks for drawing my attention back to this observation, David. When I first saw it, I could not come up with a response that I thought was helpful.

I’ll give it a longer look.

Very best,


The smooth stipe bases…
By: Dave W (Dave W)
2015-08-20 19:28:52 CDT (-0400)

appear to lack any type of volval remnants. But the in-situ photo appears to show deposits either on the collar of the stipe base or perhaps on the ground. Caps appear to lack marginal striations, otherwise I may have proposed sect. Amanita.

Created: 2015-08-20 12:56:37 CDT (-0400)
Last modified: 2015-08-29 11:18:56 CDT (-0400)
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