Observation 298498: Boletus L. sect. Boletus

Growing near live oaks with pine fairly close too. Bulbous stipe with conspicuous white reticulum. Stuffed pores (I think). No staining.

They seem a bit desiccated, but they still look delicious.

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Proposed Names

75% (2)
Recognized by sight
2% (3)
Recognized by sight
Used references: “NA Boletes” reports this species as far south as Mississippi.

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= Observer’s choice
= Current consensus


Add Comment
By: I. G. Safonov (IGSafonov)
2019-06-05 13:52:55 CDT (-0400)

I guess you will have to ask Dr. Dentinger about his greater plans. :-)
My guess, he will at minimum continue to update the big porcini ITS tree on his website with all the new Boletus s.s. taxa he comes across, thanks in part to citizen science. Even if this sp. nov. is not formally described (something that should ideally be done, and you could be instrumental in this task), one would hope it will at least make it into Dr. Dentinger’s next porcini study as a data point in phylogenetic trees.

By: Logan Wiedenfeld (LoganW)
2019-06-05 13:35:03 CDT (-0400)

This is really cool news! Great work, Igor. I’m now eager to learn what Dr Dentinger will do with this finding.

Very cool!!
By: Ryan Patrick (donjonson420)
2019-06-05 12:38:27 CDT (-0400)

Indeed a unique find! Good work Igor keep us posted.

Dr. Dentinger’s comment
By: I. G. Safonov (IGSafonov)
2019-06-05 11:13:07 CDT (-0400)

“MO298498 is new! Very interesting position phylogenetically in the core porcini clade, but on a long branch near the base. Very, very exciting discovery!”.
Logan, as per Dr. Dentinger’s request, I will be sending him a portion of this collection. I am sure you have no objections to that. :-)

Hello, Logan
By: I. G. Safonov (IGSafonov)
2019-05-29 22:33:38 CDT (-0400)

I just emailed Dr. Dentinger the sequence. I will post additional info here once I know more (hopefully soon).

By: Logan Wiedenfeld (LoganW)
2019-05-29 22:17:35 CDT (-0400)

This is exciting news, Igor! Thank you for getting it sequenced.

I’ve already seen this guy around town this year and am exited to learn he is indeed a stranger. I can’t wait to hear what Dr Dentinger has to say.

ITS sequence is in…
By: I. G. Safonov (IGSafonov)
2019-05-29 21:53:40 CDT (-0400)

…and it is quite unique. Not only there is nothing close in GenBank, but structurally this sequence is so unusual that it returns BLASTn data with the query cover of no more than 66%, and the E value for all the hits is not zero. Running ITS1 and ITS2 separately leads to the same pattern. The ITS2 sublocus is quite long (450 bps).
Clearly, this is a porcini genetically, but BLASTn results are useless to place this critter into a sub-clade within Boletus s.s./porcini s.l. Maybe it doesn’t even fit into any of them and sits by itself… I need to forward this to Dr. Dentinger — maybe he can make sense of it.

“Stuffed pores”
By: I. G. Safonov (IGSafonov)
2017-11-13 22:04:11 CST (-0500)

This trait is the unifying morpho-feature of all members of Boletus sect. Boletus, i.e. porcini s.l., in which “Alloboletus” belongs. A few other boletes have it too (e.g., Boletus auripes, Tengioboletus glutinosus, and some Butter Boletes), meaning that it may or may not be a plesiomorphic character.
I am even less confident this is separans. Older separans may look like nobilis, and young fbs can appear almost white, lacking the lilac tones in both the cap and stipe, but I’ve never seen immature fbs with brown caps. Logan has got quite a collection here, so, if these were separans, I would expect to see some lilac color somewhere in at least one fb.

MushroomExpert says the young pores…
By: Dave W (Dave W)
2017-11-13 21:27:44 CST (-0500)

of nobilis are “stuffed”, which I interpret as meaning the same thing as the hyphal layer you mention, Igor. I wonder if separans merits consideration, here? I have seen many examples of what I believed to be separans which completely lacked the lilac tint one typically expects to see on the stipe. Widely spaced reticulations is a typical separans trait.

Yes, Dave,
By: I. G. Safonov (IGSafonov)
2017-11-13 20:16:26 CST (-0500)

the stipe morphology doesn’t fit nobilis very well, and that largely influenced my opinion. As you noted, the stipes are clavate and bulbous, the bright white base with copious mycelium contrasts the brownish upper half, the reticulation is prominent (at least in some fbs). Another interesting feature I noticed is the thick and persistent bright white PV (the hyphal layer covering the pore surface).

Hi, Logan:-
By: I. G. Safonov (IGSafonov)
2017-11-13 20:03:18 CST (-0500)

Yes, thank you, much appreciated. It’s amazing your bolete season has no signs of slowing down.
Do you think you can throw in luridellus and rubrocitrinus and anything else from your local bolete flora that you feel can benefit from sequencing? Your geographic area is so understudied…
I already have several collections from you. I hope to submit the next batch of samples sometime after New Year…

Stipes are fairly consistently…
By: Dave W (Dave W)
2017-11-13 19:35:16 CST (-0500)

enlarged below to bulbous, which does not fit nobilis. But, other aspects seem to fit this species… white reticulate stipe surface, pore surface depressed near stipe, brownish/tan cap color.

Alternatives…? Maybe what BRB now calls B. pseudopinophilus? Habitat includes pine. Maybe variipes? A hardwood associate.

BTW… probably delicious, regardless of the ID :-)

Igor -
By: Logan Wiedenfeld (LoganW)
2017-11-13 19:22:02 CST (-0500)

Would you want to sample this? I can send some your way if so.

Thanks to both you and Dave for the help. It’s exciting finding porcini-esque boletes around here :)

By: I. G. Safonov (IGSafonov)
2017-11-13 19:17:42 CST (-0500)

…is a possibility, but… My ‘gut feel’ is this critter fits the porcini s.s. subdivision of sect. Boletus better than “Alloboletus” based on the visible morphology and the currently accepted biogeographic status of nobilis. I will be perfectly fine with being wrong on this diagnosis. :-) Sequencing should definitely settle this, as the subdivisions within Boletus s.s. are readily resolved.

Created: 2017-11-13 17:34:55 CST (-0500)
Last modified: 2019-07-05 15:46:50 CDT (-0400)
Viewed: 398 times, last viewed: 2019-09-23 17:44:11 CDT (-0400)
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