Observation 186984: Agaricus L.
When: 2014-10-30
Who: SMoubray
No herbarium specimen

Notes: These stout Agaricus were found pushing through the mulch at the base of an ornamental tree in a grassy area at a shopping center.
The spore print picture is included for color purposes, however it was not in a draft free area so it’s distorted. The last picture is about 30 hours after I found it.
The caps are about 5 inches across. The stems are 1" wide and 2" long. The scales or warts are very pronounced. They are dense. There was a pleasant anise ? smell when fresh or when cut. When bruised several hours after harvesting, they faintly bruised a yellowish color.
Agaricus crocodilinus was suggested as a possibility but I’m on the east coast.


At location
2-3 hours later
spore print.JPG
Spore print
30 hours later
Agaricus spore print.JPG
Spore print sans draft!

Proposed Names

83% (1)
Eye3 Eyes3
Recognized by sight
28% (1)
Recognized by sight
60% (2)
Recognized by sight: Large size, yellowing, floccose stipe surface and veil

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

Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
Very cool find
By: Martin Livezey (MLivezey)
2016-04-29 13:51:04 CDT (-0400)

Next time you find this one, slice it down the middle and look for yellowing at the base of the stipe. If you have a sample I will try to get it on our sequencing list.

Thanks Debbie!
By: SMoubray
2014-11-12 22:09:37 CST (-0500)

I appreciate your help, time and enthusiasm. I suppose the mystery continues.

not crocodilinus.
By: Debbie Viess (amanitarita)
2014-11-12 15:59:38 CST (-0500)

just received your package Shelley, and put some of that abundant spore drop on a paper plate onto a slide.

the fact of it being spore drop rather than a gill smash mount means that these are mature spores, at their greatest size.

this is clearly NOT crocodilinus due to its small spores: 5 × 6 microns.

still, good to know for sure. it is some other local Agaricus species with a cracked cap due to environmental conditions. that is actually also true for crocodilinus, which can have a far less dramatic smooth cap … but where’s the fun in THAT??!

Thanks Debbie
By: SMoubray
2014-11-05 00:29:11 CST (-0500)

Thanks for all of the info, Debbie. I’d be glad to send you chunk. I appreciate the comments and help.

just read your intro here …
By: Debbie Viess (amanitarita)
2014-11-04 11:10:39 CST (-0500)

apparently this DID bruise yellow. also, the fb’s look to be on the small side. crocodilinus get HUGE.

you are not the first to want to put that name on a white squat Agaricus that has big warts. Unfortunately, it takes more than that to make an ID. If this was easy, it wouldn’t be so much fun!

Welcome to the wonderful and challenging world of fungal taxonomy! ;)

Agaricus are NOT easy to get to species!
By: Debbie Viess (amanitarita)
2014-11-04 10:18:01 CST (-0500)

on either coast. There are very few sightings of confirmed crocodilinus online. This sp. is apparently synonymous with A. megaspore, which does make sense, since they both have mega-spores! Dry conditions can cause cracking on just about any Agaricus cap, but especially in exposed grassy areas vs a woodland environment.

A. arvensis will yellow quite promptly, and is often yellow right in the field. I see no sign of this on your fruit body here. However, the only eastern example of “crocodilinus” that I could find was a sighting from 2005 from Renee Lebeuf, a wonderful photographer and very talented taxonomist out of Quebec.

Microscopy will be necessary to nail this ID. Someday we’ll even have Kerrigan’s Agaricus of North America book to help us along, but it is not available yet, tho it seems to be just around the corner.

Help Rick, help!!!

Like I said, tough group. Much easier to just get it into the edible vs “barficus” groups by odor: phenol for the bad guys, a variety of more pleasant odors for the good.

You could always mail me a crispy dried chunk containing gills in a hard sided container and I could do the micro for you here. My mailing address is on my MO page. IF this is crocodilinus, it would extend its known range.

Awesome observation!
By: Martin Livezey (MLivezey)
2014-11-03 22:29:02 CST (-0500)

Shellie, you are off and running!

Thanks, Debbie and Walt
By: SMoubray
2014-11-03 21:56:49 CST (-0500)

Thanks to you both for comments and suggestions.

Debbie, I did save both specimen and spore print. If I can get access to microscope, I’ll take a look. I got a much better print, minus a draft!

Walt, There was no frost, however we did have a very warm day followed by a 30 degree drop shortly afterward.

Thanks again for your time,

Agaricus arvensis
By: walt sturgeon (Mycowalt)
2014-11-03 10:49:29 CST (-0500)

or a closely related species will crack like this under certain weather conditions, usually after a frost.

interesting find!
By: Debbie Viess (amanitarita)
2014-11-03 10:37:23 CST (-0500)

crocodilinus are found in grass, they are short stemmed and they only sometimes have a cracked warty cap; this is weather dependent. The surest way to know is to look at the spores under a scope … they are huge!

Did you save any, or dry any or even just save that spore print? That would work.

Any almond/anise-odored Agaricus is edible, and these were no doubt delicious, if you tried them. I have no idea if they have been found before in Virginia. Try contacting Rick Kerrigan, NA Agaricus expert. He also has an MO account.

They are saprobic, so not really associated with any particular tree, introduced or not.

Created: 2014-11-01 23:46:31 CDT (-0400)
Last modified: 2014-11-12 22:48:57 CST (-0500)
Viewed: 128 times, last viewed: 2017-06-20 20:12:58 CDT (-0400)
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