Observation 23065: Leccinum Gray

When: 2009-07-09

Collection location: Lackawanna Co., Pennsylvania, USA [Click for map]

Who: Dave W (Dave W)

No specimen available

Flap of tissue along cap margin. Found in hardwood area (mainly oak), but some small spruce trees nearby. Cut stalk stained faintly and very slowly blackish.


Copyright © 2009 Dave in NE PA
Copyright © 2009 Dave in NE PA
Copyright © 2009 Dave in NE PA
Copyright © 2009 Dave in NE PA

Proposed Names

92% (2)
Recognized by sight

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Add Comment
Proper taxonomy
By: Irene Andersson (irenea)
2009-07-12 05:41:32 CDT (-0400)

needs a good original description. In this case there is an excellent drawing of Boletus aurantiacus by Bulliard:

Anyone who cares to translate the description? I don’t read french that well..

It also seems like Schaeffer’s Boletus rufus actually is an older synonym (I don’t know why it’s considered illegitimate).

In this case I trust that Noordeloos et al have done the research that is needed to provide the right taxon with the right name. It doesn’t matter if some earlier keys and books have mixed up this one (aurantiacum) and the white-stemmed that grows with aspen only (“albostipitatum”). At least Den Bakker & Noordeloos have sorted out one of my own problems!

Okay, this is exactly what I mean
By: Gerhard Koller (Gerhard)
2009-07-11 17:19:06 CDT (-0400)

The species now named L. albostipitatum is this species that I got to know as L. aurantiacum/L. rufum mycorrhizal with aspen only. But sorry I did not recognize that Noordeloos also changed the name of the well-known L. quercinum to L. aurantiacum and therefore adding much confusion. I don’t know what is the sense behind these eternal changes of a well-known name. It just makes no sense to me and aggravates me. It should be forbidden furthermore to continue with this taxonomic tohuwabohu and one name should not be changed anymore. There should be consistency finally. The guys dealing with nomenclatural rules should fix that one and for all :)

By: Irene Andersson (irenea)
2009-07-11 16:50:10 CDT (-0400)

L. albostipitatum is another, pale-stemmed species that grows only with aspen, possibly a synonym to Leccinum aurantiacum var. pallidipes Smith, Thiers & Watling.
L. aurantiacum is a generalist, that I have seen with both oak and aspen (also known with Betula and Salix), often with a reddish brown zone of scabers in the middle of the stem.

Have a look at this site:

Who does say L. quercinum is the same as L. aurantiacum
By: Gerhard Koller (Gerhard)
2009-07-11 16:23:01 CDT (-0400)

is maybe sitting in a lab doing DNA stuff but does not know L. quercinum!!! I can tell both species apart in the field with eye only. L. quercinum has much darker colors and diverse colored scabers on the stalk … all is more brownish-reddish than in L. aurantiacum where there is all orangeish …
Besides if you trust the man who has synonymized both the correct name would be L. albostipitatum.

B/R/B includes L. piceinum
By: Dave W (Dave W)
2009-07-11 08:31:23 CDT (-0400)

in their big book of NA boletes. I just noticed it is pictured in the preface area of the book (missed it as I broused the Leccinums the other day). They mention spruce. There were some 8 foot tall spruce trees about 25 to 30 feet away. The photo in the guide looks an awful lot like my specimen; also the faint blackish staining seen on the cut flesh matches what I saw on mine (very faint and slow).

Good point about the small birch or aspen; those thin trees hide pretty well. This was not a spot I am likely to visit in the near future. So we may never know.

In the meantime, if I run into any robust red capped scabers growing nearby oak or pine I’ll examine the rest of the surrounding trees more thoroughly.

Leccinum aurantiacum group is a good idea
By: Irene Andersson (irenea)
2009-07-11 05:28:06 CDT (-0400)

I agree with Michael Kuo in his article
that aurantiacum is not impossible in oak and aspen habitats in North America.

The european name L. quercinum is a synonym (impossible to tell any difference between the ones growing with oak and aspen).

Gerhard also mentioned L. piceinum, not likely in this case because it has very dense and black scabers on the stem and a dark brownish red cap.

By: Johannes Harnisch (Johann Harnisch)
2009-07-10 17:22:30 CDT (-0400)

I guess just call ti the Leccinum aurantiacum group,

To set things straight
By: Gerhard Koller (Gerhard)
2009-07-10 16:36:15 CDT (-0400)

L. aurantiacum (formerly L. rufum) in the sense of European authors has always been associated with aspen and aspen only. If in some literature there also is cited under pine then confer to L. vulpinum (although there are some varieties described which seem to be species of their own). L. vulpinum is said to be connected with pine exclusively. The species growing with oak and seldom with aspen is L. quercinum and thus it looks. But I don’t think European species names can be applied to American species. In Leccinum you Americans have much more species than us Europeans (as in almost every genus; how I envy you all:( ) and mostly have their own names. You should get in contact with Ernst E. Both who does a lot concerning American Boletes in general. And BTW, are you sure there were no birch or aspen trees nearby, even small young ones? The occurrence of spruce would point to L. piceinum but I think this one does not occur in America. I found some species supposedly growing under oak (of which I am not really convinced): L. parvulum (description does not fit), L. roseoscabrum (southern Florida only),L. sublutescens (a possibility if mycorrhiza with conifers is confirmed) and L. subspadiceum (wrong color of the hat). But as Leccinum still remains a poorly known genus worldwide there are many riddles still to be solved.

By: Dave W (Dave W)
2009-07-10 15:42:17 CDT (-0400)

not withstanding intercontinental species designation, based upon my first guesstalt I would also want to call this L. aurantiacum; except I do not think of this species as being an oak associate. I generally apply this name to ones found under conifers. Seeing it in oak woods was a surprise. Kuo mentions L. vulpinum as an aurantiacum like hardwood associate. (This name has already been applied as a potential ID for another of the Leccinum posts I made here at this site.) Knowing that L aurantiacum is applied to European oak loving types is interesting. I suspect these red capped Scaber types with the cap margin tissue are not yet well understood.

By: Irene Andersson (irenea)
2009-07-10 10:06:40 CDT (-0400)

I don’t know if you actually have any of the species we recognize in Europe. If you do, I’d call this Leccinum aurantiacum (growing mainly with oak and aspen).