Found in landscaped area in between sidewalk and street in Downtown Bend, Oregon. Growing in bark and dirt under large Ponderosa tree. Growing in a clump of three. Observed no staining, had a sweet Almond smell.

Species Lists


Copyright © 2017 Debbie Viess
Laurence Boomer found this Agaricus and sent a packet of spores to Debbie to examine with her microscope, leading to the conclusion it is an Agaricus arvensis, Thanks Debbie!

Proposed Names

20% (3)
Used references: PNW Mushroom Id facebook page, All That the Rain Promises and More.
55% (1)
Recognized by sight: similar to crocodilinus in many respects, but lacks the cogwheel velar patches on PV near cap edge.
Used references: “Agaricus of NA,” Kerrigan
Based on microscopic features: has far smaller spores than does crocodilinus
Based on chemical features: does it yellow in KOH?

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= Observer’s choice
= Current consensus


Add Comment
I agree.
By: Debbie Viess (amanitarita)
2017-06-03 17:32:09 CDT (-0500)

and I have no problem with Laurence posting my photo of spores here on this obsie, crediting the photog. I cannot.

MO is after all a file sharing site, and what better use than to expand one’s own MO obsie with an MO photo?!

But it is still a collaboration, whether it takes the form of one obsie or two linked obsies or ten.

would be nice
By: Danny Newman (myxomop)
2017-06-03 16:45:35 CDT (-0500)

to see micrographs made by persons other than the OP be incorporated into the OO (original observation) w/ accreditation in the image notes. this sort of collaboration doesn’t happen often, but when it does, I think it’s better to have all the information in one place. my $0.02.

received spore package.
By: Debbie Viess (amanitarita)
2017-06-03 16:22:54 CDT (-0500)

spores too small for crocodilinus, a good match for large-spored concept of A. arvensis Moller.

Spores elliptical, thick walled, with moderate apiculus. 7-7.5 × 4.5-5 microns.

I will create another obsie to show micrograph of spores:

Many of the Section Arvenses Agaricus can look superficially similar, even to experts!

But this is definitely not crocodilinus, despite those intriguing cap scales.

location missing
By: Danny Newman (myxomop)
2017-05-27 13:55:14 CDT (-0500)
how big?
By: Debbie Viess (amanitarita)
2017-05-27 11:14:50 CDT (-0500)

best way to ID crocodilinus is thru its giant spores.

Created: 2017-05-27 10:53:05 CDT (-0500)
Last modified: 2017-06-04 12:28:03 CDT (-0500)
Viewed: 76 times, last viewed: 2019-10-13 19:50:16 CDT (-0500)
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