Observation 24813: Boletus L.

When: 2009-08-27

Collection location: Strouds Run State Park, Athens, Ohio, USA [Click for map]

Who: Dan Molter (shroomydan)

No specimen available

Proposed Names

15% (4)
Recognized by sight
60% (2)
Recognized by sight
-10% (2)
Recognized by sight: Boletus species with B. bicolor-like coloration, but that blue in their pileus & stipe flesh, as well as in their pores. These may induce GI upset (painful bloating), especially if not cooked very well and eaten in sufficient quantity, that differs from discomforts associated with eating too much butter in decadent meals. This group is not well-studied, but is becoming more and more known as people find said mushrooms and experience GI upset who did not experience it with the standard B. bicolor group.

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= Observer’s choice
= Current consensus


Add Comment
B. bicolor group” name…
By: I. G. Safonov (IGSafonov)
2014-07-27 21:55:12 MDT (-0600)

… in my understanding of MO nomenclature culture encompasses all the uncertain taxa that have the morphology and the color scheme that sort of fit the species concept of the true B. bicolor. In other words, this convenient umbrella name is very misleading as it is a dumping ground for cryptic species that (a) might already have proper published names or (b) are not necessarily genetically related to B. bicolor. Furthermore, as far as bicolor look-alikes are concerned, B. sensibilis or B. pallidoroseus could be considered part of this group (depending on one’s definition of it), which makes this label to vague to be of use. The name “False B. bicolor group_” adds another layer on uncertainty and confusion. Thus, calling your mushroom the generic and well-established name on MO for unknown boleti, i.e. “Boletus L.”, is most appropriate at this time.

By: Sam.Schaperow (Sam.Schaperow)
2014-07-27 21:24:59 MDT (-0600)

Interesting :), but to reply non-humorously:
So, the more uniform bluing could be a unicolor of sorts, but the distinct yellow and red are so very bi-color. And of course, in that so many people have picked this while thinking it was B. bicolor, probably the most clarifying name is false bicolor (but group, of course), or in more detail as it was written.

Why not…
By: I. G. Safonov (IGSafonov)
2014-07-27 21:17:17 MDT (-0600)

… calling it Boletus unbicolor instead? :)

bi-color lookalikes
By: Sam.Schaperow (Sam.Schaperow)
2014-07-27 21:02:47 MDT (-0600)

I and some others I know may have been the GI victims of a bi-color lookalike w/the extra bluing characteristic. They were cooked and not especially undercooked, either. This was one incident, and I also know the then-president of a mycological society in the East told me that some of their society had a similar experience from some such mushrooms found in CT.

However, when I then very thoroughly cooked another specimen I had on hand (we’re talking well-done!), I didn’t get any GI symptoms. Its hardly scientific (though if the very well cooked one got me GI symptoms, that would have been more telling), but it does suggest the possibility that if one finds what seems to be a bi-color, but gets more blue than expected (and in areas not typical of bi-color), that it is possible very thorough cooking will solve the problem. Making a sauce w/them where you may saute and then cook more in another manner could also negate potential GI irritants. Quantity likely matters as well.

Though this vid. has the flaw of not having a picked-that-day specimen, I think it is still illustrative of some of the differential bluing characteristics it has vs. a regular bi-color:

Sam Schaperow, MSMFT, LMFT
Clinical Director
PsychologyCT.com (Psychology CT)
Based in New London County in Connecticut

If there is any bluing of context
By: Dave W (Dave W)
2009-09-01 12:22:41 MDT (-0600)

on my bicolor collections, it is faint. The bluing on the stipe surface is usually a fairly dark shade of blue. I agree about the tubes being very shallow for bicolor. And, yes, I forgot to include the speciosus group in my previuos comment about possibilities.

More bicolor
By: Bill (boletebill)
2009-09-01 10:36:39 MDT (-0600)

The classic and consistent Boletus bicolor found in CT does blue when handled on the stipe, especially on young mushrooms, but DOES NOT blue in the context when cut in half. The ones that are the most suspicious look-alike different species are the ones that DO blue in the context and the ones with slightly thicker tubes. Bicolor has exceptionally short tubes.

Bill Yule

Here in NE PA
By: Dave W (Dave W)
2009-09-01 05:52:29 MDT (-0600)

most of the bicolor that I’ve found over the past few years does blue on both pores and stalk. But I’ve lately been running into a lot of reddish capped yellow pored boletes that exhibit variable bluing reactions which are likely not in the bicolor category. I’ve been unable to get species IDs for some of the these… the sensibilis types, miniato types, and a few others have occurred as possibilities. A few different chemical reactions would likely be needed to get IDs for these types. Collected some boletes yesterday that look a lot like the ones seen here… will post tonight.

Eating B. bicolor.
By: Paul Derbyshire (Twizzler)
2009-09-01 01:12:51 MDT (-0600)

“Everywhere I’ve gone this year people are cautioning against eating bicolor for these reasons.”

Wouldn’t throwing out any whose flesh blues when they’re cut in half eliminate the suspected toxic sub-species?

“Sorry for the long comment.”

There’s nothing to apologize for. If you’ve got a lot to say in one place, it’s better than leaving a lot of short comments. :)

More bicolor
By: Bill (boletebill)
2009-08-31 23:52:30 MDT (-0600)

Thanks for the update on your previuos post of B. bicolors. Not to be long-winded but I’d like to say this: Boletus bicolor is by far the most common bolete in Connecticut. In a good year, like last year, one can easily pick 1,000 of them. In CT they are distinct in that the flesh never blues when cut nor do they have a beveled cap as in your earlier finds. They do change dramatically over time though, mostly in color. The pores always blue. Having said that I’m in total agreement with Walt Sturgeon, Bill Roody, Gary Lincoff, Noah Siegel, John Plische and a host of other accomplished east coast field mycologists that B. bicolor is a complex species cluster of look-alikes that varies from different areas and that there are crytic species of bicolor types that DO blue when cut and DO cause gasto-intestinal upsets. To make things even more confusing there are populations of the look-alike Boletus sensibilis that barely blue and DON’T have the characteristic curry or tumeric smell. Everywhere I’ve gone this year people are cautioning against eating bicolor for these reasons. Sorry for the long comment.

Bill Yule

more obs of the same patch
By: Dan Molter (shroomydan)
2009-08-31 22:32:22 MDT (-0600)

The mushroom in this photos was growing in the same area as these other mushrooms found earlier in the summer.


This is an area of high fungal diversity, so they need not be the same species, but I’m pretty sure they are.

Not B. bicolor
By: Bill (boletebill)
2009-08-31 20:50:40 MDT (-0600)

I’d have to say that this is likely in the Boletus speciosus group, but definately not bicolor. It’s a beautiful looking mushroom though.

Bill Yule