Observation 74976: Alessioporus rubriflavus J.L. Frank, A.R. Bessette & A.E. Bessette

When: 2011-08-26

Collection location: Wharton State Forest, Burlington Co., New Jersey, USA [Click for map]

Who: I. G. Safonov (IGSafonov)

No specimen available

A single basidiocarp growing at the base of a stump with pitch pines around. An all-yellow basidiocarp with some red at the base of the stipe and a few pale red-rose patches on a beat up “pockmarked” pileus. Delicately recitulated on the upper third of the stipe; reticulation is yellow. All parts of this bolete, including the pileipellis, instanly and intensely turn blue.


Bluing of the context immediately following dissection
Left half = staining of the context with ammonia (aq);
Right half = staining of the context with 3% KOH (aq)
Staining of the pileipellis with aqueous ammonia (left and center) and 3% aqueous KOH (on right)

Proposed Names

-2% (6)
Used references: “North American Boletes” by Bessette-Roody-Bessette
-19% (5)
Recognized by sight: reticulated stipe, red flesh in stipe’s basis
-39% (3)
Recognized by sight
-8% (3)
Recognized by sight: coniferous habitat..

Please login to propose your own names and vote on existing names.

Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
Thank you
By: I. G. Safonov (IGSafonov)
2013-03-29 10:41:11 WIB (+0700)

Dear All,

Thank you for a lively and profound discussion. It’s been a while since I collected this interesting and distinct-looking bolete, and thus was very much surprised to suddenly see so much forum activity for this observation.

I called this specimen B. pseudosulphureus because it was the closest match in the Bessette/Roody/Bessette book on NA boletes, which at the time was pretty much the only printed reference I used before I finally got a nice copy of Smith and Thiers some months later.

It’s not uncommon to have two different mushrooms – on from the Old World and the other one from across the Big Pond – to bear the same name. Perhaps the American pseudosulphureus will be renamed following genetic studies.

As far as the habitat is concerned, there were definitely no oaks in the immediate vicinity; the leaf you see in the picture must have been blown over from far away. I remember where I collected this specimen, so I will be on the lookout for it this year and save a sample in case someone wants to run a DNA trace on it. :-)

Also, take a look at Obs. №106340 from 2012, which could the same robust-looking species from a similar habitat (the Coastal Planes) in Delaware.

I know that the line can miss.
By: Gerhard Koller (Gerhard)
2013-03-29 06:21:41 WIB (+0700)

But as Irene said this is a case for further investigation. But I am afraid no one will do it.

By: Jiri Soucek (Jiri Soucek)
2013-03-29 05:35:15 WIB (+0700)

Gerhard, there are some leaves visible in the first picture. Maybe there was a broadleaved tree nearby (oak?).
Btw. the bataille line can be missing in some cases. Last week I was told about a find of B. luridus subsp. caucasicus (identified by reputable boletologist) which lacked it. I was told, that during dry weather the line may be not distinct.

Another guess.
By: Gerhard Koller (Gerhard)
2013-03-29 05:07:22 WIB (+0700)

Mr. Klofac made me aware of another bolete that could be your find – which is illustrated in N.Smith-Weber & A.H. Smith: Field Guide to Southern Mushrooms under the wrong name “pseudosulphureus”. Habitat: “under pines” . B. luridus + varieties do have a distinct red zone between cap and tubes in fresh state. Chemical macroreaction testings with KOH and NH4OH are not necessary in Boletus ss.str. they are not reliable. Melzers is good for separating this group. So what could fit is Boletus holoxanthus only that this species is known from the South West with oaks. The red parts where maggots did their work are mentioned explicitly!

By: Irene Andersson (irenea)
2013-03-29 00:41:21 WIB (+0700)

pseudosulphureus is hardly a useful name for an american species with reticulate stem. It doesn’t matter how it has been interpreted in North America.
It was described from Germany and the non-reticulate stem was particularly stressed. It’s probably the same as junquilleus -aka yellow form of luridiformis.

The whole original description can be read at
Choose journals – Annales Mycologici – volume 22 – page 239.

I agree that this obs is most likely a non-european species and that is should be investigated with molecular methods.

B. pseudosulphureus and reticulation
By: Jiri Soucek (Jiri Soucek)
2013-03-29 00:08:42 WIB (+0700)

Yes, it may be quite confusing. B. pseudosulphureus was described by Kallenbach in Germany and his description was later considered to be identical with B. (luridiformis v.) junquilleus. As Kallenbach (1924) wrote, the stipe is – “ohne Spur eines Netzes” = without any sign of reticulation. According to Pilat and Dermek (1974, EU approach) it’s “bez sietky, jemne plstnaty” = without reticulation, slightly tomentose. According to Smith & Thiers 1971 (US approach) it is “smooth end merely pruinose”, too. Even according to Michael Kuo (mushroomexpert.com) it is “yellow overall; smooth; not reticulate”. At least in this sign the EU and US approach should be identical. It seems to me, that the confusion has arised from the description in North American Boletes. I don’t have access to this publication, but all other EU/US publications I have seen yet don’t admit reticulated stem for this specie.

What you also have to keep in mind IMO
By: Gerhard Koller (Gerhard)
2013-03-28 23:21:44 WIB (+0700)

is that the American concept of B. pseudosulphureus is not identical with the European concept of B. pseudosulphureus/junquilleus/gabretae.

Bessette & Roody
By: walt sturgeon (Mycowalt)
2013-03-28 22:53:14 WIB (+0700)

In North American Boletes mention that the stipe of B.pseudosulphureus may be reticulate near the apex and may also show red staining at the base.

B. luridus
By: Jiri Soucek (Jiri Soucek)
2013-03-28 21:35:08 WIB (+0700)

Boletus luridus is known from N. America and I see no reason, why it couldn’t create xanthoid form/variety there (it’s not related to location). I know, that N. America has very rich set of bluing Boletes. But I can’t find any common specie in the Luridi section, which combines typical boletoid habitus (non satanoid, non xerocomelloid), reticulated stipe (coarse reticle), significant zone of red flesh in the lower part of stipe and this level of bluing (with the exception of mentioned B. luridus). Anyway, thank you for your opinion.

You’re right. I didn’t say
By: Gerhard Koller (Gerhard)
2013-03-28 20:58:02 WIB (+0700)

it is B. pseudosulphureus but I do not believe in fo. primulicolor too. And no way in gabretae which hasn’t been found outside Central Europe.
What I am trying to say is there are so many Boletes in North America that I believe this is something completely different, an American species of its own.
At least I cannot think of another possibility.

You’re right. I didn
By: Gerhard Koller (Gerhard)
2013-03-28 20:56:25 WIB (+0700)
By: Jiri Soucek (Jiri Soucek)
2013-03-28 15:23:20 WIB (+0700)

according to Sutara, Janda and Miksik, B. luridus v. primulicolor grows in the same localities as common form of B. luridus – often together with fully-colored fruitbodies. I’m not trying to convince anybody to believe, that this must be B. luridus v. primulicolor. But definetely it can’t be B. pseudosulphureus.

By: Gerhard Koller (Gerhard)
2013-03-28 06:02:00 WIB (+0700)

okay, what you say is correct but do not forget one thing: this observation is from North America. And there are a lot more “xanthoid” Boletes than in poor Europe are. I may err but I never heard Boletus luridus fo. primulicolor to occur outside Europe. Me self has seen this form only once in thermophilic alluvial forest in Austria in 2002.

Likely not B. pseudosulphureus
By: Jiri Soucek (Jiri Soucek)
2013-03-28 05:28:45 WIB (+0700)

I’m sorry, but this can’t be B. pseudosulphureus. B. pseudosuphureus is currently accepted as a synonym for xanthoid variety of B. luridiformis (B. luridiformis v. junquilleus). But this mushroom isn’t B. luridiformis, because B. luridiformis doesn’t have a reticulated stipe. Additionally, B. luridiformis doesn’t have red flesh at the stipe’s basis. Reticulated stipe and red flash are quite typical for Boletus luridus. Xanthoid variety of B. luridus is called B. luridus v. primulicolor. There’s one more xanthoid variety of B. luridus, which is called Boletus gabretae, but this one is reported to grow only under Picea abies in cold areas. I think this mushroom can be B. luridus v. primulicolor.

Created: 2011-08-31 10:20:24 WIB (+0700)
Last modified: 2017-10-18 00:53:17 WIB (+0700)
Viewed: 529 times, last viewed: 2018-07-17 00:41:52 WIB (+0700)
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