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Observation 242156: Boletaceae Chevall.

Found in moss near oak and beech. Rained heavily two days ago but the ground was not sodden. The area is known for black trumpets but they were not out yet. Lots of russula and a few early amanitas. This was a surprisingly mature mushroom compared to everything else found on the walk.

No red hairs by the base. I asked several local identifiers who were there, and all of us agree that this species does not display that characteristic in our area.

Some of the pictures were taken in shadow and there was bruising from being handled, but the overall color of the cap and stipe were distinctly yellow with lots of orange tones. The reticulation became dark, but may have been reddish when fresh.

It’s hard to see, but there is a thin bad of yellow by the edge of the pores. Could be visible flesh in a spot where the pore layer is very thin.

Flesh (context) was a distinct yellow that blued before a photo could be taken.

Texture was classic bolete, dry and meaty without being crumbly or chalky. Nothing viscid or sticky.

Some notes on the chemicals:

  • Ammonia produced weak reactions, but had the effect of turning the entire area of surrounding pores to yellow.
  • KOH had the strongest reaction across the board, and even 30 minutes later it was still wet and glistening. The other chemicals absorbed or evaporated quite quickly. No idea why. Same size drops, amounts, etc.
  • There was a distinct difference in scale between the effect of a drop on the cap flesh and the effect on the stipe flesh. It was most notable with the KOH, which was clear red on the cap flesh and bright orange on the stipe flesh.
  • The bluing faded all around where the chemicals were placed.
  • Ammonia on cap: Weak orange. Darkened but still there 30 minutes later.
  • KOH on cap: Distinct orange/red. Darkened but still there 30 minutes later.
  • FeSO4 on cap: Slowly became gray/olive. Faded to dark gray/brown 30 minutes later.
  • Ammonia on cap flesh: Orange/red. Faded to dark after 30 minutes.
  • KOH on cap flesh: Bright red. Still red, glistening, and wet after 30 minutes.
  • FeSO4 on cap flesh: Olive yellow. Faded to dark gray after 30 minutes.
  • Ammonia on stipe flesh: No reaction except for the blue staining going away. After 30 minutes the bluing returned, but still no reaction.
  • KOH on stipe flesh: Bright orange, versus the red on the cap flesh. Dark orange after 30 minutes. Drop is gone, but the area still appears much wetter than where the other chemicals were applied.
  • FeSO4 on stipe flesh: Yellow, with much less olive than on the cap flesh. Faded to dark gray after 30 minutes.
  • Ammonia on pores: Dark gray. The red pores faded to yellow all around where the chemical was applied.
  • KOH on pores: Bright red liquid area, with grayish effect on the surrounding pores. They did NOT turn yellow as with the ammonia.
  • FeSO4 on pores: Olive/yellow. Surrounding pores unaffected.

Context of the base showed no reaction to any of the chemicals

SUBSEQUENT NOTE: A sample was rehydrated for DNA testing. The distilled water dyed blue even from this tiny sample.


Distinct reticulation, but NOT by the pores
Reticulation may have been red before getting handled. Bluing of bright yellow flesh was almost instant.
Bright yellow flesh blued before the photo could be taken. Note that the reticulation does not reach the top.
Reticulation may have been red before getting handled.
After 10-15 minutes.
Ammonia (weak reaction, up from almost nil). KOH (Brown, down from bright orange). FeSO4 (green, down from olive)
Ammonia (cap left, stipe bottom), KOH (middle), FeSO4 (Cap right, stipe top). Taken 10-15 minutes after application.
Ammonia (weak orange), KOH (distinct orange/red), FeSO4 (slowly became green/olive).
Ammonia, KOH, FeSO4.
No red hairs whatsoever! I asked a number of local identifiers and all concur that we never see that supposed feature in this area.
Yellow flesh blued immediately. Taken in shadow.
Taken with a flash.
Ammonia, KOH, FeSO4. NOTE: Different reaction on the stipe flesh than the cap flesh! Ammonia was orange/red on the cap (far left) and essentially no reaction on the stipe (bottom). KOH was bright red on the cap flesh and bright orange on the stipe. FeSO4 was yellow on the cap fl...
Natural light only.
Ammonia, KOH, FeSO4. NOTE: Different reaction on the stipe flesh than the cap flesh! Ammonia was orange/red on the cap (far left) and essentially no reaction on the stipe (bottom). KOH was bright red on the cap flesh and bright orange on the stipe. FeSO4 was yellow on the cap fl...
Ammonia, KOH, FeSO4
Good shot of reticulation and bruising. Taken in the shade, which hides some color.
All the bruising came from simple handling. Was the reticulation reddish before turning dark later on?
Yellow flesh blued within seconds
Mycelium… white? Not visible?
More reticulation. Stipe color distinctly yellow with orange tones. NO RED HAIRS BY THE BASE

Proposed Names

-31% (3)
Recognized by sight
Used references: North American Boletes. Bolete Filter.
Based on chemical features: Ammonia, KOH, Iron Salts. Drops placed on cap skin, cap context, stipe context, and base context. Shamefaced admission: I forgot to do the stipe skin.
20% (3)
Used references: North American Boletes. Photos in the bolete filter.
Based on chemical features: KOH results almost match.
-28% (1)
Used references: North American Boletes. Photos on bolete filter, especially the cover photo (
-28% (1)
Recognized by sight
Used references: Plugging the characteristics into the Bolete Filter. But there is no “faint smell of chlorine”
Based on chemical features: There was no blue/green flash, but stained flesh did turn back to yellow
45% (2)
Recognized by sight
-17% (2)
Recognized by sight: Compare to Observation 243202, which was established as rubriflavius by DNA
Used references: BENA
Based on chemical features: KOH result matches BENA

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

= Observer’s choice
= Current consensus


Add Comment
Amazed by the amount of blue
By: Scott Pavelle (Scott Pavelle)
2017-06-20 14:46:04 -05 (-0500)

A sample was rehydrated for DNA testing. The distilled water dyed blue even from this tiny sample!

You mean pores aging to yellow and then to olive?
By: Scott Pavelle (Scott Pavelle)
2017-06-03 17:38:27 -05 (-0500)

I saw it. Seems a little odd that it would stop reddening, but what do I know?

And yes, we are definitely looking forward to some actual results! Perhaps Oddballus cerritulus?

By: I. G. Safonov (IGSafonov)
2017-06-03 16:55:37 -05 (-0500)

carefully read the description of rubriflavus in BENA… I am afraid to say that when you sequence 242156, you will be disappointed to find out it’s not rubriflavus. But it could be a new red-pored taxon that shall have your name attached to it. :-)

Geoff Balme’s observation that you sequenced
By: Scott Pavelle (Scott Pavelle)
2017-06-03 13:37:54 -05 (-0500)

Observation 243202 has been confirmed as rubriflavus. It’s pores are yellow turning toward orange. This is an older specimen, so it is reasonable to keep projecting that shift, which I have seen in other mushrooms quite often. But that’s just a reaction to the biggest weakness that you’ve pointed out. Look at the similarities.

The netting on both is quite distinctive and very similar – that odd, dark green/black higher up getting red or orange toward the bottom. That’s what made me think of this one.

Then there’s the odd, dark iodine blue/gray shading. It’s not a weird enough blue to be distinctive, but it is notable enough to raise an eyebrow. And it’s identical in both, as well as in the BENA photo.

Then there’s the KOH reaction, which also ties in to what’s in BENA.

And there’s the overall look and feel of a larger and meaty bolete.

Finally, they were both in-between riddlers that didn’t match up to anything else for a similar set of reasons, and had similar suggestions to things like luridus.

So.. With the exception of the added red in this one’s pores, a feature I’m willing to explain away because 243202 was clearly getting redder with age, it all makes sense. Certainly enough to post the suggestion and get feedback! [grin] It will get sequenced eventually and then we will know. But I really do think rubriflavus is a closer match than any of the other suggestions to date.

Why rubriflavus, Scott?
By: I. G. Safonov (IGSafonov)
2017-06-03 08:56:00 -05 (-0500)

Your bolete has red pores!

This one drove us nuts last year. Now I know why!
By: Scott Pavelle (Scott Pavelle)
2017-06-03 07:45:30 -05 (-0500)

I just finished inputting A. rubriflavus into the Bolete Filter, which led to examining the specimens on M.O. that Igor has proven through DNA results. I’m tempted to go all the way up to “I’d call it that” based on the comparisons.

This will eventually be DNA tested too.

I see you saved a specimen Scott…
By: Bill (boletebill)
2016-06-21 11:03:08 -05 (-0500)

…this would be an excellent candidate for comparison with European material since the named settled out here to be a well know European taxon. I have not found any red-pored bolete in CT with the same combination of conspicuous features. The distinct longitudal ridge-like reticulation is unusual in red pored boletes in my experience Very good documentation Scott.

we may not be able to settle this here …
By: Debbie Viess (amanitarita)
2016-06-20 11:22:46 -05 (-0500)

but it won’t be for lack of documentation!

Last year
By: I. G. Safonov (IGSafonov)
2016-06-19 11:49:55 -05 (-0500)

I came into the possession of obs206608 thinking that the bolete would be a good fit for S. luridus based on the morphology alone. It wasn’t. Instead, ITS sequencing revealed genetic affinity toward a couple of smooth-stiped European species in Neoboletus. The issue at hand is the lure of force-fitting the NA taxa into the species concepts of European boletes based on morphology alone.
Now, ITS “fingerprinting” that works so well for the agarics may not be enough for resolving species in the Boletaceae; another gene perhaps can do a better job, except that, unlike it’s the case with ITS and LSU, many fewer data points will be available for mining in GenBank. Still, I think that some kind of “barcoding” should be done for our project, if circumstances permit. This is a decision that can be made later down the road.
With regard to the chemical tests, we should continue doing them as discussed previously. However, I think that we may see a consistent staining pattern with Ammonia/KOH/Fe(II) with many of these red-pored types.

Reticulations probably started red.
By: Scott Pavelle (Scott Pavelle)
2016-06-19 10:26:53 -05 (-0500)

Look at image #15, which was taken early.

I don’t have first-hand experience with S. luridus.
By: Dave W (Dave W)
2016-06-19 09:05:51 -05 (-0500)

But there are several features in this observation which seem to point toward this species.

1. Chemical reactions match (as reported on MushroomExpert).
2. Reticulations are prominent and vertically elongated.

Although not explicitly mentioned on either ME or CduQ, a few of the photos show (prominent) reticulations on only the lower 3/4 of the stipe, with a relatively smooth surface near the apex. Also, a few of the photos (ME/CduQ) show areas of the reticulations darkened (to black), similar to what is seen here, except Scott’s specimen appears to have reticulations completely blackened. I doubt this represents the original color of the reticulations. I think the blackness is likely due to either aging and/or handling.

The modern species concept…
By: I. G. Safonov (IGSafonov)
2016-06-19 01:07:40 -05 (-0500)

…for B. subvelutipes out there (NAB/BRB, William Roody’s book, MushroomExpert and other printed/online resources) has been considerably expanded and modified since C.H. Peck first described the species in 1889 to better circumscribe this variable-looking taxon, and possibly other similar-looking taxa, growing in diversified habitats of hardwoods or helmlock-hardwood forests.
Here is the original description penned by Peck:
Boletus subvelutipes N. SP.
Pileus convex, firm, subglabrous, yellowish-brown or reddish-brown, flesh whitish, both it and the tubes changing to blue where wounded; tubes plane or slightly convex, nearly free, yellowish, their mouths small, brownish-red; stem equal or slightly tapering upward, firm, even, somewhat pruinose above, velvety with a hairy tomentum toward the base [the italics are Peck’s], yellow at the top, reddish-brown below, varied with red and yellow within; spores, .0006 to .0007 in. long, .0002 to .00025 broad.
Pileus 2 to 3 in. broad; stem 2 to 3 in. long, 4 to 6 lines thick.
Woods. New York, Peck.
This species resembles the preceding one [B. vermiculosus] in general appearance, but it is very distinct by its much longer spores and by the velvety hairiness toward the base of the stem.”

Among the conserved features of this entity that all the existing descriptions seem to agree on, are a smooth stipe and the presence of red or yellow stiff hairs on the bottom of the stipe. Now, Scott’s mushroom lacks the hairs and has a reticulate stipe, though interestingly enough the reticulation doesn’t originate from the apex. So, in all likelihood this is not B. subvelutipes.
I gave Suillellus luridus some consideration, but I don’t think it’s a good fit either. Hence, gents, IMO the best proposal at this time is Boletaceae.

In my experience
By: walt sturgeon (Mycowalt)
2016-06-18 19:54:22 -05 (-0500)

chemical tests are often unreliable. No doubt the age of the fruiting is one factor but the amount of pigment on the cap and stem is another. Boletus separans for example can have different ammonia reactions on the same cap depending on where the drop hits. Also there is the interpretation of the color produced. I am not saying the tests aren’t worthwhile. They are a piece to the puzzle often as a clinching factor but they should not be relied on too heavily.

Sorry Dave – Habitat was mostly oak
By: Scott Pavelle (Scott Pavelle)
2016-06-18 19:04:51 -05 (-0500)

I don’t think that’s unusual for subvelutipes. Beech in the area too, but that was mentioned mostly for the sake of being thorough.

Other possibilities – luridus, rhodosanguineus, and pseudo-olivaceous
By: Scott Pavelle (Scott Pavelle)
2016-06-18 19:03:24 -05 (-0500)

The reticulation bothered me too, but what else fits the description?

Suillellus luridus is supposed to have prominent red reticulation, but it’s supposed to get heavier toward the top rather than disappear. There’s also supposed to be a red line in the cap flesh right above the tubes, and that was not present here. The chemical tests are off too – KOH turns luridus dark red to blackish on the cap (true) and orange-yellow on the cap context (false – this turned red, though the stipe flesh was yellow-orange).

Rubroboletus rhodosanguineus has a similar description, but it is exceptionally rare around here (JP-III has found it only once) and is supposed to have a distinctive smell of over-ripe fruit. This just smells bolete-y.

Boletus pseudo-olivaceous can have netting, but this has no “faint chlorine smell” and it lacks the blue/green flash when ammonia was put on the cap context. Though the staining did go away.

Note that there are no reported chemical tests for rhodosanguineus, only KOH results for luridus, and similarly limited reports for pseudo-olivaceous. This is another reason to get specimens like this one identified – the careful notes we are taking would be useful additions to the general pool of knowledge. BTW, can one species display widely different chemical results from specimen to specimen?

Finally, take another look at the chemical tests performed on the pores. (Image #13). Ammonia turned all the surrounding pores from red to yellow, while KOH had no effect! Has anyone ever seen something like that before? It’s kind of striking and would make a fantastic field characteristic if it’s reliable for only a few species.

None of what I have called subvelutipes…
By: Dave W (Dave W)
2016-06-18 18:37:27 -05 (-0500)

has ever exhibited reticulate stipe. Could this be a variety of subvelutipes (a-la the reticulate bicolor variety)?

Habitat also differs from what I associate with subvelutipes. My observations are made in areas where conifers are present, usually hemlock. MushroomExpert describes subvelutipes habitat as oak-dominated hardwood forest.

Scott, I think this observation highlights exactly the types of issues we wish to address with the red-pored types.

Good documentation
By: walt sturgeon (Mycowalt)
2016-06-18 16:58:30 -05 (-0500)

Boletus subvelutipes is not supposed to be reticulate.

nice work
By: Robert(the 3 foragers) (the3foragers)
2016-06-18 15:27:32 -05 (-0500)

Good observation Scott.