Observation 115296: Agaricus L.

Definately a different Agaricus species. Abundant fibrils on cap with odd violet-tinged surface. I don’t know if that was it’s normal coloration or just the abundant rainfall we’ve just had.


Abundant cap fibrils, especially near cap edge.
I tried to get a close-up of a broken piece of the cap. Flesh is mostly white, gills mostly violet-black.

Proposed Names

5% (3)
Used references: Arora, Mushrooms Demystified. Arora notes the cap color can be quite variable. Hope Rick Kerrigan sees this obs. Distinctive violet fibrils on cap. Older specimen, I dropped this on site and it shattered.
55% (1)
Recognized by sight

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

Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
Thanks for the comments, Noah.
By: Daniel B. Wheeler (Tuberale)
2012-11-03 13:11:41 CDT (-0400)

Your points are important.

The fibrils were larger than most others I’ve seen. But I haven’t seen many on Agaricus before, either.

This was rather large, at least for my area. The cap is probably 5 to 6 inches across. I’m going to look for some again today.

There was no staining. But the specimen was rather large and waterlogged: perhaps that affects staining?

Perhaps I can find another specimen today. A little more light today as well should make better photos possible.

This mushroom
By: Noah Siegel (Noah)
2012-11-03 10:45:59 CDT (-0400)

Does not look like A. lilaceps to me for a few reasons.

-Wrong kind of fibrils/scales on the cap, these are way to stringy, look at other observations of lilaceps on this site to compare.

-Size matters. lilaceps is big, real big and chunky. Yours looks to small/thin to be lilaceps.

-Staining: There is no sign or mention of red staining on yours, something that lilaceps does and does well…

Out of “range” doesn’t bother me as much as it does Christian. I just can’t see any reason to call these A. lilaceps base on the information in this observation.

Apparently you missed the point as well, Christian.
By: Daniel B. Wheeler (Tuberale)
2012-11-03 02:46:43 CDT (-0400)

Several years ago I acted as host for a truffle forage on my parents’ property near Lebanon, Oregon. While there, I showed off a shrub that shouldn’t be there: Holly-leafed cherry, or Prunus ilicifolia. The furthest north this rather distinctive shrub’s “known” range was Mount Shasta, California. Suddenly here are several slow-growing specimens 15-25 feet tall, more than 250 miles north of the “known” range. Nancy Smith Weber was among those who saw the shrubs.

Shrubs can change by hundreds of miles with a single collection. So too can fungi change “known” ranges.

Have you heard of Amanita phalloides and its spread along the West Coast? First identified from San Francisco in the early 1980’s. By 1995 had been found in Vancouver, British Columbia.

Or perhaps you are unfamiliar with mushroom cultivation? When Dr. Henry Mee first convinced the USDA to allow the importation of live Lentinus (now Lentinula) edodes to San Francisco in 1976, then rapidly spreading outward to include much of the rest of the United States? I was the second person in Oregon to fruit this mushroom, after Dr. William Dennison.

Thank you for suggesting that "it is very unlikely that [I} found A. lilaceps in Portland. That helps so much in identifying this observation.

But you’re right: maybe I should include a photo of shiitake I currently have flushing in my front room. Then again, maybe I’ll just eat the evidence.

By: Christian (Christian Schwarz)
2012-11-02 21:59:02 CDT (-0400)

You missed the point. By saying it is ‘only locally common within its limited range’, I mean that it is very unlikely that you found A. lilaceps in Portland.

Your images, while technically photos, don’t constitute evidence. They don’t show anything of value for identification. The cap looks like an Agaricus in terms of texture, but the color balance is way off – everything (including your familiar finger) is strongly tinged bluish. The gill shot is equally not useful.

For a report of a rare species, out of range, a full-fruitbody shot accompanied by a description and a preserved specimen would be the minimum to incline me to believe in such a large range expansion for such a geographically limited species.

The global warming comment is… not useful. Yes, global warming causes range shifts, but no… it doesn’t usually push things over large intermediate gaps with no records in between, especially uncommon/rare species.

The North American Mycoflora Project would be well served by setting up a records committee like the bird folks have done (http://www.californiabirds.org/). A record like this would be rejected.

If you still want to provide a written description here, please do so. If indeed this was A. lilaceps, I would like to know that, undoubtedly. It would be a great record. But from what you’ve provided here, there is nothing to indicate that.

While it may be locally common,
By: Daniel B. Wheeler (Tuberale)
2012-11-02 12:03:02 CDT (-0400)

this is a first obs. for me. A single sporocarp says uncommon. I’ve never seen an Agaricus with distinctive fibrils on the cap before. We rarely find Agaricus most years. Lilaceps seems a very good fit, at least in Arora. And as noted in Arora, the cap can be quite variable in color.

As for the range: welcome to global warming.

Agaricus? That’s a given. See my original notes and photo captions.

I don’t understand your last comment: “It shouldn’t be reported so far from its known range without more evidence.” I just provided photographic evidence. Should photographic evidence of Tuber in Southern CA not be reported because of its unusual range? I think not. The known range for Tuber gibbosum extends into Mexico, and ranges northward to southern Alaska.

If, OTOH, you wanted specific information, you probably should ask for it: staining, chemical, microscopy, etc. BTW, there was no staining. I do not have the luxury of a mushroom lab.

By: Christian (Christian Schwarz)
2012-11-02 09:21:13 CDT (-0400)

not enough information in the description or in the photo to suggest A. lilaceps, which is only locally common within its limited range. It shouldn’t be reported so far from its known range without more evidence.

Created: 2012-11-02 01:01:53 CDT (-0400)
Last modified: 2016-11-22 09:02:22 CST (-0500)
Viewed: 77 times, last viewed: 2017-06-14 09:20:32 CDT (-0400)
Show Log