Observation 108582: Boletopsis grisea (Peck) Bondartsev & Singer
When: 2012-08-29
Herbarium specimen reported

Notes: This mushroom was found at about 7000 ft. in the Sierras by Terry Caudle, in a mixed conifer forest, predominantly lodgepole pine within a 50 ft. radius. It was growing in the duff. It was extemely bitter.

Proposed Names

-44% (2)
Recognized by sight: a macro-toss-up between Jahnoporus and Boletopsis; if Boletopsis, oddly fused caps.
Based on microscopic features: nodulose spores discovered in a single, more mature area of the hymenium.
small amount of spores found earlier on this same fruit body that were a perfect match for Jahnoporus goes unexplained. over-all, mostly spore-free.

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Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
What we can conclude…
By: Dimitar Bojantchev (dimitar)
2012-09-15 22:54:17 CDT (-0400)

Just looked into that paper (Watling & Milne) and poked around some of the sequences (EF457900 is way too short to be of much use).

What we can conclude is that in Western North America:

1) We do have Boletopsis grisea (100% matching collections between Finland and Oregon)

2) We do have another species, which is related, but not the same.

As far as Mike’s material from Sierra Nevada – it is Boletopsis, but which
species, I wouldn’t bet more than whether it will be a dry or rainy winter…


good to know that the ID of these species…
By: Debbie Viess (amanitarita)
2012-09-15 12:07:05 CDT (-0400)

have been confusing folks for many years. welcome to the crowd!

thanks for the link to this paper, Noah. the pine hab mentioned by Mike also lends credence to the grisea ID.

Thanks Noah!
By: Irene Andersson (irenea)
2012-09-15 11:08:52 CDT (-0400)

Very interesting -
MO obs 57347 looks like a good candidate for Boletopsis perplexa..!

More on Boletopsis
By: Noah Siegel (Noah)
2012-09-15 07:14:37 CDT (-0400)
grisea and leucomelaena
By: Irene Andersson (irenea)
2012-09-15 01:43:14 CDT (-0400)

can hardly be told apart by the spores, more by colours and habitat, but there are some other subtle micro characters too.
Both species have good descriptions in MycoBank.

similar spores?
By: Debbie Viess (amanitarita)
2012-09-15 00:17:39 CDT (-0400)

I’ll take anything for this! what an epic ID.

back we go to Boletopsis…
By: Debbie Viess (amanitarita)
2012-09-14 12:24:56 CDT (-0400)

see the BAMS list for the discussion:


Sometimes, these IDs just won’t stay nailed down! ;)

In spite of the microscopy,
By: Mike McCurdy (lesmcurdy)
2012-09-11 03:08:52 CDT (-0400)

which I do appreciate, something seems wrong about this. Admittedly I’m basing this on images vs. microscopy, and microscopy does carry a lot of weight. After sifting through lots of images, I can’t find an example of Jahnoporus or Polyporus that shows the oddly lumpy cap shape that this specimen has. However, on page 557 of Mushrooms Demystified there is a photo of a Boletopsis species whose cap is nearly identical in shape to this one. Someone suggested Jahnoporus in part because of the bitterness, but Boletopsis can also be bitter.

Terry has offered to look for more, so maybe he can find a more mature specimen overflowing with spore, that might offer a better opportunity to come to conclusions about this.

all characters line up for Jahnoporus…
By: Debbie Viess (amanitarita)
2012-09-07 12:16:46 CDT (-0400)

bitter taste, fused caps, and most important of all, the micro.

The fruit body that Mike so kindly sent me had very very few spores…but in the midst of pore tissue I found a single cluster of
spores, fusiform, smooth and hyaline, within the size range of Jahnoporus. They were CERTAINLY not the angular and irregular spores found in Boletopsis, our second best guess.

Michael Sampson first proposed this ID (Jahnoporus hirtus) on the BAMS list, and he was right on, despite my initial skepticism.

These two species are quite similar in their macro-morph. My original guess was also Boletopsis, but I must change my vote with the micro-evidence. The fact of the clustered fruit body also lends credence to the Jahnoporus theory; I have never seen Boletopsis with fused caps; has anyone else? I do wish that I had been able to see the fresh specimen, but gosh, life is sometimes unfair! ;)

No micrograph available, alas: my camera is on the fritz.

Created: 2012-09-04 02:49:00 CDT (-0400)
Last modified: 2012-09-16 07:26:54 CDT (-0400)
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