Observation 48518: Rhizopogon Fr. & Nordholm
When: 2010-07-12
Herbarium specimen reported

Notes: under pine.

[admin – Sat Aug 14 02:05:29 +0000 2010]: Changed location name from ‘Salt Point State Park, Sonoma CO, CA’ to ‘Salt Point State Park, Sonoma Co., California, USA

Species Lists


thin section through gleba.
1000x in Meltzers.
spores thick-walled, smooth, ellipsoid, oil contents,
8 × 3.5 microns
1000x in water.

Proposed Names

75% (2)
Eye3 Eyes3
Recognized by sight: growing at the base of the striped coral root orchid.

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Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
Running it through Key to Spores of the Genera of Hypogeous Fungi…
By: Daniel B. Wheeler (Tuberale)
2013-06-07 12:53:05 CDT (-0500)

is keys out as Rhizopogon. It also keys out as Alpova, Truncocolumlla, and Gastroboletus. Not Alpova, which is gell-filled and usually sticky. Not Truncocolumella, as no meandering columella present. Not Gastroboletus as it lacks a stipe.

I think this has to be Rhizopogon.

Then ran it through How to Know the Non-Gilled Mushrooms. And didn’t find it!?! This appears to be the Stirps Luteolus. There are no blue or purple Luteolus.

Too many things to point out in one post.
By: Daniel B. Wheeler (Tuberale)
2010-07-21 01:49:51 CDT (-0500)

Columella absent. There is no hint of cartilaginous columella typical to Hysterangium.

With all due respect to Mr. Brun, I was told only one person had been successful in cultivating Corralrhiza striata: Dr. Helen Gilkey. But the successful cultivation first required her to cultivate Rhizopogon vinicolor. In order to grow R. vinicolor, you must also grow Pseudotsuga menziesii. Dr. Gilkey said she did this work in her front yard. I have no reason to doubt her.

I don’t believe this is R. vinicolor. The vinaceous staining typical to R. vinicolor does not appear to be present, at least to my eye.

Some Rhizopogon can have tiny spores. Your microscopy appears to show spores about 7-8 × 3-4 microns: relatively small for Rhizopogon, but in Smith’s original concept of the species, well within bounds.

In Field Guide to North American Truffles by M. Trappe, F. Evans and J. Trappe, Rhizopogon ater is described as having a “…firm,charcoal gray to nearly black, and entirely green when mounted in potassium hydroxide (KOH).” This is somewhat ironic, I feel, since I contributed one of the few collections, and was present when Adrian Beyerle made another collection at the same site outside of Falls City, Polk Co., Oregon. My collection had distinctively moist gleba shot thru with strands of silver, as if a black fabric had been woven using occasional silver thread. My collection looked completely black with silver highlights. But the photo of R. ater in the above looks to my eye to be a dark royal blue color with no hint of silver threads. I cannot say where that color came from, but can say it was not present in the collection I found that was later identified as R. ater. There was no pine present at the Falls City site at all. Yet your collection is described as being near pine. Which of itself would seem to preclude the possibility of Rhizopogon ater.

Your observation contains neither columella nor sterile base that I can see. It does, however, have multiple rope-like rhizomorphs on the peridium, easily seen when the first photo is enlarged.

There is one other slightly odd thing I notice on your photographs: when blown up, the right-hand specimen shows a peridium which might be 2-layered (upper left-hand side), but that does not carry through to the other side of the gleba.

The spores appear small for most species of Rhizopogon. While the size may be similar to Hysterangium, there is nothing else to suggest Hysterangium in your photos.

I do not believe this is a Hysterangium. It is my opinion this is a Rhizopogon, possibly one of the less-collected species, with tinier than usual spores.

I cannot put my hinds on my copies of Smith, Smith & Weber’s How to Know the Basidiomycetes; nor Key to the Genera of Hypogeous Fungi of North Temperate Forests, with Special Reference to Animal Mycophagy. I’m fairly certain one or both of those books will yield clues as to the probable identify of this collection. But until then … a voucher collection would be almost as good .

Rhizopogon, or Hysterangium???
By: Debbie Viess (amanitarita)
2010-07-20 20:10:08 CDT (-0500)

not sure what species (or genus) we might have here. no apparent columella in the cross-section.

I did some microscopy today, photos added.

BTW, here’s what Dr. Tom Bruns had to say about this truffle, including a debunking of its association with Corallorhiza:

“Debbie – The Corallorhiza association is a red herring, as they are only associated with Tomentella or Russula (depending on the species of Corallorhiza). The gleba on that truffle seems too dark for pogon, especially pogon with a white perdium. Is the color right, or alternatively could it be Hysterangium?” – Tom

Just enlarged 1st photo.
By: Daniel B. Wheeler (Tuberale)
2010-07-13 21:35:36 CDT (-0500)

I don’t see the silver strands that ought to be there, so probably not Rhizopogon ater. But the peridium appears to bruise purplish, a rather uncommon color in Rhizopogon in my experience. Might make this Rhizopogon subpurpurescens.

Did you know?
By: Daniel B. Wheeler (Tuberale)
2010-07-13 21:25:11 CDT (-0500)

Corallorhiza striata (Striped coral-root) gains most of its nutrients by stealing them from Rhizopogon? LaRea J. Dennis told me she thought the relationship was with Rhizopogon vinicolor. But this collection does not appear to be R. vinicolor, at least to my eye. It looks more like Rhizopogon ater, and if confirmed, would be a considerable extension of known range. Rhizopogon ater is relatively rare, and is known from just 3 or 4 collections that I know of. I found it near Falls City, Oregon, in Polk Co. It is fairly easy to distinquish from other Rhizopogons in that the gleba is nearly black in color with silver highlights in it. Similar to a fabric which has silver thread woven into it. Very unusual for that reason. Do you have any spore details? Do you remember if Douglas-fir was nearby or any other tree species?

Created: 2010-07-13 19:37:08 CDT (-0500)
Last modified: 2010-08-14 14:37:35 CDT (-0500)
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