Observation 213886: Aureoboletus innixus (Frost) Halling, A.R. Bessette & A.E. Bessette

When: 2015-08-23

Collection location: Hickory Run State Park, Pennsylvania, USA [Click for map]

Who: Dave W (Dave W)

No specimen available

According to BRB, these are large for innixus. Relatively short spores eliminate auriporus and subtomonetosus. No staining observed. Two specimens, each solitary. Birch, hemlock, maple, cherry, and some oak present in this part of the forest.

Proposed Names

44% (3)
Recognized by sight
Based on microscopic features: Spore lengths 8-11 mu.
Based on chemical features: KOH mahogany-red on cap. Ammonia amber/brown on cap without a green flash on specimen B, but with a green flash and somewhat persistent green halo for specimen A. Chemicals applied to post-mature specimens several to many hours after collection.
41% (4)
Recognized by sight: According to Index Fungorum.
28% (1)
Recognized by sight
-29% (4)
Recognized by sight

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Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
LOL, Alan…
By: I. G. Safonov (IGSafonov)
2015-08-24 23:49:13 CDT (-0500)

An attempt at humor I suppose. If not, are you suggesting sect. Luteoscabra by any chance?

By: Dave W (Dave W)
2015-08-24 23:22:46 CDT (-0500)

innixus is not a species I find very often. But I think this is an example.

By: I. G. Safonov (IGSafonov)
2015-08-24 23:04:22 CDT (-0500)

I admit you could be right after all. You collected and studied this material exhaustively whereas I only have pix, albeit good ones, to work with. Your knowledge of northeastern boletes is, without a question, superb, so I find it difficult to argue with your assignment given the true facts I just stated. :-)

Aside from the pores…
By: Dave W (Dave W)
2015-08-24 22:56:46 CDT (-0500)

not being bright yellow on mine (to be expected with old material) I don’t see a lot of difference. The stipes on mine are not as bulbous as what one may expect with innixus, but they do have the basic shape… thin at the apex, thickening downward, but somewhat abruptly tapered at the base. The second photo from the top shows this on specimen A. Also, the stipe bases have appendages similar to what one sees on the one Mushroom Expert photo.

These may be old, with colors somewhat faded, and perhaps a bit stretched out from maxxed-out growth, but I think the innixus proposal matches very well with what’s available… spore size/shape (elliptical) and chemical reactions (at least for specimen A) are exactly what is expected for innixus.

By: I. G. Safonov (IGSafonov)
2015-08-24 22:32:28 CDT (-0500)

Yours are old and beat up specimens, but still they should be readily recognizable as P. innixus. It’s such a distinct bolete. I still have my doubts…
See Dario’s obs 213991 for what I call the classic innixus.

Igor, the color of the stipes…
By: Dave W (Dave W)
2015-08-24 22:20:59 CDT (-0500)

matches very well with what is seen in the innixus photos at Mushroom Expert.

Hickory Run features very few oaks. But each of these specimens was collected in an area where oak was present (different spots… maybe 100 yards or so apart).

The one labeled “A” in the photos was still in my possession until a few minutes ago. (Old material, bug infested, getting moldy, so I just chucked it.) I tried a drop of ammonia on the cap, and this time I got the green flash preceding a reddish/amber reaction. Checked for an odor, but the old material simply smelled like old rotting material.

I believe these two mushrooms are the same species. I think they are examples of innixus.

Interestingly, the one labeled “B” was found very close to where I had made another interesting bolete collection last year. obs 146000

By: I. G. Safonov (IGSafonov)
2015-08-24 21:36:37 CDT (-0500)

P. innixus usually has a bulbous base with a rootlet even if growing singly. It also has a unique reaction to ammonia (I think) and a sharp “chemical” odor. The stipe of your specimen is predominantly reddish brown, whereas typically it’s yellow ground color with prominent vertical brownish streaks. The habitat also points way from it as it’s a predominantly oak associate.

Created: 2015-08-24 19:41:06 CDT (-0500)
Last modified: 2016-02-02 17:14:34 CST (-0600)
Viewed: 123 times, last viewed: 2018-01-10 17:30:27 CST (-0600)
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