Observation 105183: Boletus subcaerulescens ( E.A. Dick & Snell) Both, Bessette & A.R. Bessette
When: 2012-08-12
No herbarium specimen

Notes: Bluish bruising on pores.

I don’t think this is an example of B. subcaerulescens. B. subcaerulescens has a more bulbous stipe, the stipe is more completely and more coarsely reticulate, and it grows with pine.

Under hemlock.

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Eye3 = Observer’s choice
Eyes3 = Current consensus


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This mushroom…
By: Dave W (Dave W)
2014-07-30 10:10:46 CDT (-0400)

did not fit my previous concept of B. subcaerulescens… bulbous stipe, overall darker color, occurrence with pine. But a very similar bolete recently collected from the same area exhibited bluing and matched the chemical-reactions expected for subcaerulescens. obs 171279

Thanks I. G. and yes
By: Ron Pastorino (Ronpast)
2012-08-27 23:22:21 CDT (-0400)
that is the study I was referring to. Also, your interpretation of the paper pretty much is the same as what I got out of it. When I said I thought B. subcaerulsecens was loosely related to the true edulis clade, I also meant to add….but more closely related than Xanthoconium species. However, I have to agree with Walt that these collections do LOOK more Xanthoconium-like(except for the bluing).
2010 Porcini Clade Paper
By: I. G. Safonov (IGSafonov)
2012-08-27 22:28:47 CDT (-0400)

Here is the link for those who are brave enough to read it: http://static.msi.umn.edu/rreports/2010/211.pdf

The paper is very scientific and, with exception of the introductory section, went over my head. Frankly, I didn’t even attempt to peruse the central portion of it, but I did take a look at the phylogenetic trees in order to understand where X. separans and B. subcaerulescens are in relation to each other. The major conclusion of the study is that the porcini clade is likely to be monophyletic.

According to this paper, X. separans and B. subcaerulescens are both porcini-like boletes, sensu stricto Smith & Thiers (1971) and Singer (1986).

Ron, I think the paper suggests that B. subcaerulescens has much more B. edulis character in it than X. separans — see the second paragraph in the right column on page 1277. Also, if my interpretation of the “porcini tree” on page 1285 is correct, Boletus subcaerulescens is claded together with B. pinophilus, B. fibrilosus, B. regineus, and B. rex-veris. Xanthoconium separans is not on that tree!

Though I don’t think this paper gets us any closer to resolving the dilemma at hand, I still believe that B. edulis group is the most accurate moniker we can give this collection, and perhaps that of Obs. #105182, at this point in time, pending further evidence, macroscopic, microscopic or molecular.

Perhaps a rather simple test
By: Ron Pastorino (Ronpast)
2012-08-27 22:18:35 CDT (-0400)

to eliminate either Xanthoconnium or Boletus subcaerulescens for either this Observation or # 105182 is to get a spore print.
Xanthoconiums have spore prints primarily with reddish, orange, yellow or brown colors while Boletus subcaerulescens(and many other Boletes) has a “deep smoky olive” color"

Finally I looked more closely
By: Ron Pastorino (Ronpast)
2012-08-27 21:34:59 CDT (-0400)

at the description and photos of Boletus subcaerulescens in the Bessette Bolete Book. The description is fairly close to the original Dick and Snell description but the photos are rather varied and seem to lack the forms with the pinkish-brown caps(?).
More questions than answers and I guess as someone said earlier, some further DNA studies on these questionable collections would be very helpful.
I still think the light blue staining of the pores is distinctive and basically eliminates Xanthoconium as that genus is currently defined.

I’m again wading into this pond
By: Ron Pastorino (Ronpast)
2012-08-27 21:00:42 CDT (-0400)

from my armchair and without any hard experience with this species ( as far as I can remember ) but I’m still confused as to specifically why Boletus subcaerulescens is being rejected as a good possibility, at least per the original description by Dick & Snell of Boletus edulis subsp. subcaerulescens.Unfortunately I also can’t figure a way to attach photos of the text and colored drawings from “Boleti…”.
However, in the description, it notes the vinaceous-brown color of the cap, the light blue bruising of the pores, the reticulate stipe which is concolorous +/-, and the stipe not being bulbous, but “irregular and somewhat longer than broad”.
From my western perspective, I certainly would never have considered these an edulis type or variety but we have to go with what has been published and I believe some current DNA studies have put Boletus subcaerulescens only loosely related to the true edulis clade.

Looks like
By: walt sturgeon (Mycowalt)
2012-08-27 20:04:14 CDT (-0400)

a Xanthoconium to me. The staining is unusual but in my opinion it’s closer to X. separans than to the species in the edulis group.

By: I. G. Safonov (IGSafonov)
2012-08-27 16:43:48 CDT (-0400)

I completely agree with your comments below, especially regarding the semblance between X. separans, B. gertrudiae and B. nobilis, especially at maturity. However, I think we are trying to rule out X. separans in this case due to the pore mouths staining blue-gray…

Just to add to the muddy waters…
By: Bill (boletebill)
2012-08-27 16:24:47 CDT (-0400)

… it seems to me X. separans has a remarkable degree of polymorphism, including but not limited to stature(short and chunky or tall and slim and everything in between), color (whites, tans, violets, blush wine, etc.) reticulation (fine, heavy, non-existant) staining reactions (it all depends on where your add reagents and if the specimen still has color where you test. And how close in every respect are the mushrooms we call Boletus nobilis and B. gertrudiae? There are many times when I think they’re all the same mushroom.

Here we go again…
By: I. G. Safonov (IGSafonov)
2012-08-27 16:15:37 CDT (-0400)

If this unknown taxon looks like a hybrid of X. separans and B. subcaerulescens (which it does), both of which ARE in the B. edulis group, what is wrong with placing it into that clade even with a “could be” degree of confidence, Walter?! Or perhaps we should just label it as Boletus or Boletacea to make everyone happy!

The white stipe reticulations…
By: Dave W (Dave W)
2012-08-27 11:29:53 CDT (-0400)

is a trait that I do not associate with B. subcaerulescens. But, this is based upon my own limited observations of what I have IDed as B. subcaerulescens.

Edulis group…
By: Bill (boletebill)
2012-08-27 10:01:17 CDT (-0400)

works for me with this one. The blue/green tube stain is sort of off base for most of the edulis types I find in CT but I also tend toward subcareulescens when I see this in an edulis type mushroom in the east.

Good luck,
By: I. G. Safonov (IGSafonov)
2012-08-26 21:27:48 CDT (-0400)

Dave! We need some local “big guns” in phylogenetic research to step in and get this thing and the one from the previous posting sequenced…

I really need to get back there…
By: Dave W (Dave W)
2012-08-26 21:10:25 CDT (-0400)

and collect some of these for study. In competition with the local boletivores, though! So this may be no easy task.

By: I. G. Safonov (IGSafonov)
2012-08-25 15:26:52 CDT (-0400)

A very interesting observation. I also “proposed” B. subcaerulescens just by looking at the mushroom and without reading the comments. The combination of the lilac, reticulated stipe and the blue-gray staining of the tubes made me think that. From that perspective alone, no other mushroom described in B-R-B comes close in appearance to the textbook X. separans as B. subcaerulescens. Of course, the overall stature and the hemlock-dominated habitat are against B. subcaerulescens (usually found under Scots pine and spruce, according to M. Kuo); however, the terrain-modified mophology theory you propose might explain why the shape/length of the stipe and the mesh size of the reticulation deviates from the proportions of the typical B. subcaerulescens. The bluing of the pore surface, though difficult to interpret in light of the overall morphology, should firmly rule out X. separans. I am sure you ran the ammonia or KOH on surface to eliminate X. separans from consideration.

Lastly, some of us on MO, including yours truly, occasionally like to apply the term “Boletus edulis group” to some uncertain taxa that fit the “edulis” bill rather than conveniently rubber-stamp them as B. variipes. Yet, there is no consensus on MO as to what bolete species actualy fall under this category, which frequently leads to misunderstanding and the urge to use the “as if” button. :-) I like to use it in the sense of Kuo (http://www.mushroomexpert.com/boletus_edulis.html#key) just because he is a recognized authority with a published interpretation of the term, though other bolete experts may tacitly disagree with him. Interestingly, Kuo’s “edulis group” includes an eclectic collection of species from both East and West of USA. His decision to throw in X. separans is somewhat unusual given that it’s not in genus Boletus to begin with; at the same time neither B. nobilis, nor B. nobillissimus, nor B. subcaerulescens are there. Eventually, phylogenetic studies will put an end to this and other incessant debates. Give it another 5-10 years. :-)

It seems to me that bluing on pores…
By: Dave W (Dave W)
2012-08-25 11:03:22 CDT (-0400)

would be very unlikely for a Xanthoconium species.

B. subcaerulescens would seem to be a reasonable choice here. But that type usually has a thicker stipe that is more prominently reticulate, and grows with pine. The collection seen here was made at the edge of a predominantly hemlock forest, with some birch/beech mixed in. Also, for me this mushroom does not evoke the gestalt of subcaerulescens… albeit, this is based upon my own limited experience with that species.

There has been MO discussion about bluing reactions with B. edulis. This collection looks a lot like the photo labeled “Boletus edulis (H)” in the big NA bolete book. Also, I have found, in this same area this summer, examples of other types of boletes with stipes unusually elongated/twisted. I think this may be due to the weather… one month of hot very dry conditions followed by more hot/warm days and plenty of rainfall. My idea is that the first boletes of a given type to fruit tend to occur in spots where moisture had been preserved during the dry spell… nearby rocks, holes in the ground etc… spots where a mushroom stipe needs to find its way around such an obstacle.

Same type of mushroom collected on same day in similar habitat as

I collect a lot of X. separans…
By: Dave W (Dave W)
2012-08-14 01:09:47 CDT (-0400)

and I don’t think this is an example. The stipe on this collection is more brown than the photo may appear (not purple/lilac). Also, the reticulations are very tightly wound on this mushroom.

The yellowing of the context is something I associate with X. separans.

Created: 2012-08-14 00:47:30 CDT (-0400)
Last modified: 2014-07-30 22:40:33 CDT (-0400)
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