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This was growing out of soil and mulch near a creek. It has a yeasty smell, very pungent. The flesh is dark brown.



Proposed Names

-39% (6)
Recognized by sight: When enlarged to “huge” size, lower half of first photo shows vestiges of peridioles, consistent with Pisolithus arhizus. Maturity of fungus means most of gleba covered with dusty spores.

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Not Pisolithus arrhizus
By: Thomas Laxton (Tao)
2013-09-05 23:04:31 CDT (-0400)

I guarantee you that this not Pisolithus arrhizus, sorry. Look at my new image of the section.

Some are.
By: Daniel B. Wheeler (Tuberale)
2013-09-05 22:34:11 CDT (-0400)

There are exceptions.

Tao, when Pisolithus arrhizus is young, it has not had time to degrade into spores on the surface. Usually this happens by becoming supersaturated with water.

When conditions are dryer, peridium can shield most of the fungus, preventing spore release. Lest someone alledge this is only my observation, let me quote Arora from Mushrooms Demystified under Pisolithus tinctorius “SPORE CASE with a thin, brittle peridium (skin) that is variously colored (but usually yellowish, purplish, olive-black, or brown) and often lustrous and soon ruptures irregularly or flakes away. Upper portion of fruiting body containing hundreds of seedlike peridioles which gradually disintegrate, turning into a crumbly or dusty mass of brown spores (the disintegration process STARTS AT THE TOP OF FRUITING BODY AND PROCEEDS DOWNWARD).” Emphasis mine.

I believe what is seen here is spore masses with peridium still attached.

Cut the fungus from base through the top, and show the result. Maybe this is the extraordinarily rare Phaeolus schweinitzii without fuzzy cap or typical coloration, as Christian asserts. But if peridioles are present, it will readily be apparent.

I think almost everyone is doing that.
By: Christian (Christian Schwarz)
2013-09-05 21:38:04 CDT (-0400)
Once again
By: Daniel B. Wheeler (Tuberale)
2013-09-05 21:26:15 CDT (-0400)

cutting the specimen from the base of the stem through the top, and taking a photo, should yield concrete evidence. It is not enough what other collections have looked like. Let’s focus on the evidence at hand.

No spores release.
By: Thomas Laxton (Tao)
2013-09-05 17:46:04 CDT (-0400)

Every Pisolithus arrhizus that has gone to the brown aged state has almost disintegrated into a cloud of spore when I damage or moved it including small disfigured specimens. This did not and has not done so. I have the specimen drying and it has not released any power at all. I have to go with Christian on this identification. I have found Phaeolus schweinitzii in the same area and I do think this looks closer to the aged specimens I have found.


By: Daniel B. Wheeler (Tuberale)
2013-09-05 14:42:15 CDT (-0400)

I said “it is not withered”. I did not say ""weathered but not withered."" You misquote me. You are the one who stated “It’s withered and brown.”

I did not say weathered.

Are you saying evidence of mycophagy on this a specimen is “extraneous”? Is Phaeolus schweinitzii ever the subject of mycophagy? Look closely at the right-hand side of the third photo. The evidence is there. Something sampled this.

Slugs are known to eat what other organisms find unpalatible. Slugs might have eaten that portion of the peridium closest to the ground, leaving the peridium on top untouched.

A view of a sliced specimen would solve the question.

There are no tubes visible, as would be expected in Phaeolus schweinitzii.

This observation remains
By: Christian (Christian Schwarz)
2013-09-05 14:16:59 CDT (-0400)

correctly identified, despite extraneous information on voles, sand, eucalyptus, hypotheses of out-of-focus needles, and your assertion that it is “weathered but not withered”…

So yes, it is what it is.

And in my experience it would be weird for P. arrhizus to disintegrate on the sides first and not the top… I usually see it go the opposite way.

Enlarged view of third photo.
By: Daniel B. Wheeler (Tuberale)
2013-09-05 14:08:56 CDT (-0400)

Surface has small sand embedded in surface.

It is not small, mis-shapen, or dried-out. It is what it is.

It has tooth marks on the right-hand side of the sporocarp. Looks like vole or mouse teeth.

It is not withered, but it is brown. It appears to still have soil adherring to it.

You can see evidence of redwood. You missed the willow or eucalyptus leaf, while insisting on Douglas-fir. Douglas-fir needles may or may not be present: they are out of focus, and just as easily could be individual redwood needles.

Tao: the cap does have a sterile top or cap or even peridium. Pisolithus arrhizus can have such a peridium when very young and little weathered. The fact the sides are weathered, but the cap has withstood erosion supports Pisolithus. Slugs and mice erode the peridium quickly. Arora says it “flakes away.”

There is no fuzz on the cap, as should be present for Phaeolus schweinitzii.

I have spent no time in Santa Cruz.
By: Daniel B. Wheeler (Tuberale)
2013-09-03 22:08:21 CDT (-0400)

Why should that make any difference? Douglas-fir is the predominant tree of Oregon, and the state tree of Oregon. Phaeolus schweinitzii is common if not commonplace here.

This obs. has no pores that are visible. At any magnification.

Nor is it a gilled mushroom.

By: Christian (Christian Schwarz)
2013-09-03 21:17:32 CDT (-0400)

For anyone who’s spent time in Santa Cruz (or the western Douglas-fir forests for that matter), it’s pretty clearly a small specimen of P. schweinitzii that dried out. It’s misshapen. It’s withered and brown. And there’s very clear evidence of conifers in the photos (although it’s evidence of Redwood… a non -ectomycorrhizal tree; fear not, it frequently grows in mixed stands with Douglas-fir).

This observation 144567 is pretty clearly not Cortinarius caperatus (or even a gilled mushroom). It makes me wonder if maybe you are usually looking at MO on a cell phone? Higher resolution photographs help a lot with identification.

NOT Phaeolus schweinitzii.
By: Daniel B. Wheeler (Tuberale)
2013-09-03 19:26:19 CDT (-0400)

In Arora, cap is “…tough or corky in age, regid and brittle when dry; surface covered with a dense felty or woolly mat of hairs…” The hymenium is “mustard-yellow to greenish when fresh, but quickly becoming brown or blackish when bruised or in age; tubes 2-10mm long.” There are not tubes visible in the photos. In the west, Phaeolus schweinitzii is almost always associated with conifers. There is little evidence of any conifers in the photos.

Very young. Cap not worn off.
By: Daniel B. Wheeler (Tuberale)
2013-09-03 14:05:19 CDT (-0400)

Photos 1, 4, 5, 6 at base show peridioles. Unless fungus is sliced, peridioles not as readily visible. Presence of cap and lack of spore erosion also very suggestive of very young Pisolithus arrhizus.

Pisolithus arrhizus
By: Thomas Laxton (Tao)
2013-09-02 17:19:45 CDT (-0400)

I have found a lot of that growing around the area but this is different it has a cap of sorts instead of a ball shape and didn’t release spores when moved.