Observation 170758: Boletus bicolor group

When: 2014-07-16

Collection location: Sweet Valley, Pennsylvania, USA [Click for map]

Who: Phil Yeager (gunchky)

No specimen available

Velvety, burgundy caps 10-46mm wide x 11-26mm high with an incurved to decurved margin. Contex white, slowly developing light blue-green stains, but larval holes stain reddish. Pores yellow bruising greenish grey. Stipe 20-65 mm long x 15mm at apex, yellowish-white at apex then colored like the pileus; clavate with a white base, solid; some parts of the stipe have greenish stains. stipe contex yellow, slowly stains light blue-green with worm holes staining reddish. Found near Oak, with Hickory, Ash and some White Pine. The only chemical reactions I observed were KOH on the context was orangish, and on the stipe contextwas reddish, but the tests were performed about 8 hours after picking. WAs leaning towards B. peckii due to the red stains in context holes, but am not sure. B. bicolor var. bicolor also was considered but not enough chemical evidence to support either proposal.

Proposed Names

35% (3)
Recognized by sight
58% (5)
Recognized by sight: Recent dry weather often causes macro-abnormalities. General appearance suggests B. bicolor. See comment.

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Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
That is why
By: Phil Yeager (gunchky)
2014-08-05 10:27:48 PDT (-0700)

The authors of field guides and other reference materials mention a wide growth range, and color variants among the same species. But I have read that when chemicals are applied a certain color reaction is to be expected- with no variation- on pristine specimens. I understand that a fungus that is very young or old may not produce a reaction. That is why I try to test mushrooms in every stage of development when I find them. Recently I have been taking my chemicals on my excursions. This eliminates the possibility of dessication before testing. I’m also taking various containers to put species in for spore prints in case my friends and I stop for a few beers on our way home. Most of the time I make short notes of each find in the field.

Is there such a thing as proof when IDing mushrooms?
By: Dave W (Dave W)
2014-08-04 21:11:47 PDT (-0700)

We have a list of traits, and a given mushroom either conforms or fails to conform to the current understanding of a trait. In many cases, a described trait is a rather fuzzy concept. And there are regional variations as well as seasonal/weather-related variations.

There are examples where a given mushroom conforms to some traits associated with a species concept, and fails to conform to others… like this obs. So what does one conclude in such a case? Is every mushroom that cannot be perfectly matched to some existing list of species traits automatically a new species?

In my experience, chemical reactions are sometimes not among the most reliable identification traits. As has been previously stated (on other obses), both the time-lapse between harvest and testing and the age of the mushroom are factors that may affect the chemical reaction. I suspect there are probably other factors… amount of recent rainfall, excessive dryness, ph level of rainfall, habitat.

Perhaps molecular analysis will give way to a species concept that allows for proving mushroom X represents species Y? But I suspect that new gray areas of understanding will emerge.

Went out
By: Phil Yeager (gunchky)
2014-08-04 17:25:06 PDT (-0700)

three days or so later and picked the specimens I had left there and teasted them on the spot( within ten minute walk back to my car. None of the chemical teasts Registered Blackish on the cuticule. This, accoding to many authors should eliminate B. bicolor to my knowledge. There are many look alikes, and it never ceases to amaze me as to how some mycophiles like myself can say that they recognized a mushroom by sight without any proof whatsoever. I can understand a Mycologist with four to eight years of college, and many years of experience and lab work to make well infomrmed decisions,v but maybe I’m being unjust.

In the past I have collected boletes…
By: Dave W (Dave W)
2014-07-21 17:15:09 PDT (-0700)

that look like bicolor, do not key out as any of the usual other suspects, but differ in some seemingly significant trait(s). Here’s an example from the past.

As I reconsider collections like obs 138794 I think at least some of these probably represent bicolor, with macro-differences due to weather conditions.

Created: 2014-07-21 11:46:44 PDT (-0700)
Last modified: 2015-12-08 11:06:05 PST (-0800)
Viewed: 137 times, last viewed: 2017-06-18 09:38:29 PDT (-0700)
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