Observation 77427: Boletus fibrillosus Thiers

When: 2011-09-16

Collection location: Siesta Lake, Yosemite National Park, California, USA [Click for map]

Who: David Rust (incredulis)

No specimen available

Distinctly yellow on cap. Similar to Boletus edulis. Some called it hypomyces, but I am not convinced that was coloration. It was not soft. Found with Lodgepole pine.

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Proposed Names

-7% (3)
Recognized by sight
76% (2)
Eye3 Eyes3
Recognized by sight: if it also matches genetically.

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Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
ask Dentinger. He ran it.
By: Debbie Viess (amanitarita)
2015-10-28 10:20:34 PDT (-0700)
How close was the match?
By: Alan Rockefeller (Alan Rockefeller)
2015-10-28 10:14:14 PDT (-0700)

And which gene regions were analyzed?

this was genetically determined to be …
By: Debbie Viess (amanitarita)
2015-10-27 15:52:58 PDT (-0700)

identical to B. fibrillosus. Sometimes, at least in the Sierra, the caps are yellow.

By: Martin Livezey (MLivezey)
2012-01-19 14:04:50 PST (-0800)

From the little I know, the white reticulation puts it safely in the B. edulis group. The smooth pore surface and stuffed pores add to the assessment that it is young. The cap is underdeveloped but it looks beat up; frost may have contributed to that. I am not sure if any of this matters to the ID as a sequence is on the way. But it may provide an alternate to the suggestion of hypomyces.

ah, so that might explain it…
By: Debbie Viess (amanitarita)
2012-01-19 12:23:11 PST (-0800)

is there a sort of white “veil” covering the actual pores? this could explain why some descriptions of say Boletus fibrillosus claim that the immature pores are pale yellow when to the eye they look white.

I was referring
By: Martin Livezey (MLivezey)
2012-01-19 12:22:31 PST (-0800)

to the pale yellow translucency on the stipe between the white reticulation at the top and the big white bulb below. As an example, it reminds me of Phylotopsis nidulans after a frost. It can cause discoloration.

By: walt sturgeon (Mycowalt)
2012-01-19 12:00:49 PST (-0800)

Probably not frost, just “stuffed pores”, a feature of several boletes when immature.

By: Martin Livezey (MLivezey)
2012-01-19 11:02:01 PST (-0800)

Is it possible that is frost damage?

yeah, that guy.
By: Debbie Viess (amanitarita)
2011-11-03 13:24:40 PDT (-0700)

and that is why I am having my eyes checked tomorrow! in addition to being a generally lousy speller…

It’s Dentinger
By: Christian (Christian Schwarz)
2011-11-03 11:55:13 PDT (-0700)
this specimen is undergoing DNA analysis…
By: Debbie Viess (amanitarita)
2011-11-03 11:18:46 PDT (-0700)

by both Bruns and Dentinger, and getting compared to the rest of the porcini species analyzed by Dentinger et al in “Molecular phylogenetics of porcini mushrooms (Boletus section Boletus).”

I agree that
By: Christian (Christian Schwarz)
2011-09-27 10:28:07 PDT (-0700)

it doesn’t look like Hypomyces is parasitizing it, at least from this photo.

Created: 2011-09-27 09:21:34 PDT (-0700)
Last modified: 2015-10-28 11:18:59 PDT (-0700)
Viewed: 400 times, last viewed: 2018-12-28 14:28:26 PST (-0800)
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