Observation 218715: Radiigera Zeller
When: 2015-10-09
No herbarium specimen

Notes: A squirrel dug up this false truffle and cleverly stashed it in a snag.

Proposed Names

25% (2)
Recognized by sight
56% (1)
Used references: Field Guide to North American Truffles, by Matt Trappe, Frank Evans, and Jim Trappe.

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

Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
Yes, send them to my address on my MO page.
By: Daniel B. Wheeler (Tuberale)
2015-11-10 17:59:12 PST (-0800)

The spores of Radiigera are unexciting. The size of the spores must be the determining factor here. There is some slight variation in spore size on average, which means accurate measurement of spores.

Let’s not rush things.
By: Daniel B. Wheeler (Tuberale)
2015-11-10 17:53:43 PST (-0800)

Until I can get the spores under a microscope for confirmation of species, it may well be another less common Radiigera from CA, OR, or WA. I’d guess the unusual weather conditions which obtained this year may have something to do with this showing up in ID now.

Spores unexciting
By: Earl (EGLunceford)
2015-11-10 17:37:28 PST (-0800)

I must say that the spores are rather nondescript and unexciting. They’re round, quite opaque, and lack the prominent type of ornamentation I would have expected. There are slight spines on the exterior, but nothing outstanding. What do you make of this?

- Earl

Radiigera spore ready to mail
By: Earl (EGLunceford)
2015-11-10 17:33:48 PST (-0800)

Hello Daniel,

I’ve got what I hope are the correct spores mounted on a slide with the cover slip glued on. Should I send them to the address you posted on your page? I’m very curious about how unique this find really is. Could this actually be an undescribed species? As an aspiring young scientist, I would be thrilled at the opportunity to publish the find.

- Earl

Greetings, E.G.!
By: Daniel B. Wheeler (Tuberale)
2015-10-13 05:09:04 PDT (-0700)

I’ve had more than a little experience with truffles. I have been most of the offices of the North American Truffling Society. Since 1986, I believe I have cultivated Tubers in Douglas-fir plantations in 7 different locations, although that is being questioned by Dr. James Trappe, Dr. Charles LeFevre, Dr. Michael Castellano, etc.

I believe this is Radiigera because in your photo on the right, there seems to be the remains of a capitate columella near the center of the fungus, and radiiating lines, at least in the close-ups I’m able to see. Radiigera is among the most distinctive of false truffles (basidiomycetes, as you suspected). When young Radiigera is quite firm (hard?), but is often degraded by weather to mere blackish mass of fibers. It is the peridium which flying squirrels are so interested in, and that is often consumed as food.

Yes, I would love to see the spores if you still have them. On a slide is fine.

Elaphomyces have been called “the most common truffles of the northern hemisphere” by Dr. Alexander H. Smith. He collected quite a number of truffles and truffle-like fungi from Idaho, so I suspect you will be finding many more collections from there as well. In general, Elaphomyces are broken into two major groups: E. granulatus (which has exterior warts on the peridium); and E. muricatus, which in characterized by masses of spores within the peridium. I have found these by the tens to hundreds at a time, often in clay soil buried sometimes 6 to 14 inches beneath the soil surface. One of my more spectacular species novums, which I found in the Columbia River gorge near Bonneville Dam, has combination of green and reddish spores in the same sporocarp. Talk about distinctive! (Oh my aching eyes!)

Chris Maser has also done much work on flying squrrels and truffle mycophagy. Maser is a favorite author, as he worked with Dr. James Trappe to verify small mammal mycophagy. It was due to Maser’s work with endangered species in northern California that opened up animal mycophagy and the importance of consumption by small mammals with the spread of truffle spores. I highly recommend his works for reading, especially The Redefined Forest. Maser and Trappe’s investigation led directly to the formation of The North American Truffling Society.

In northern Clark County, I witnessed a daytime flying squirrel collision with a metal shed roof. It dazed the squirrel, which walked unsteadily away. The presence of Northern flying squirrels is a strong indication to me of my favorite truffles, Leucangium carthusianum. I am an addict of this truffle. Whenever I smell it in the forest, I must stop and search until I find it. The aromas drive me to obsessively search it out. It has flavor components of chocolate, pineapple, dried morel mushrooms, and apple. YUM! I highly recommend the similar Kalapuya brunnescens as well. Both species are associated with Douglas-fir, btw.

It is wonderful to share my passion with you, E.G.

By: Earl (EGLunceford)
2015-10-12 23:23:50 PDT (-0700)


I am a forest resources major in my fourth year at the University of Idaho, minoring in fire ecology and German.

Last summer I did a 10 wk internship in the Frank Church Wilderness. I stayed with five other interns at Taylor Ranch.
Each of us wrote and executed an independent research project while we were out there. I had a goal of cage trapping flying squirrels for the purpose of collecting their scat for truffle spore analysis. The Forest Service denied me permission to trap in wilderness however.
I settled on doing line transects through different forest types and raking for truffles. In total I found about 17 different species, including a Radiigera. The radiating lines are much more distinct in the specimen I found in the Frank Church. Thats why I thought this was Elaphomyces.

Anyway, I’m new to truffles but I’m thrilled that someone else on mushroomobserver is knowledgeable about them!

I must clarify that perhaps the peridium looked unique because the squirrel had nibbled on it. The striations across the peridium are teeth marks. I didn’t think that there were radiating lines, it appeared to be a solid spore mass. But l’m still new, like I said.

If the squirrel has not eaten that truffle ( I found it three days ago now) I could possibly recover it. I have a tiny amount of spores left in my basket I could send you if you’re curious.


Earl Lunceford
In retrospect
By: Daniel B. Wheeler (Tuberale)
2015-10-12 21:39:58 PDT (-0700)

wish you had collected this. While it appears to be Radiigera, it is a species which is new to me.

Close examination of the gleba should show radiating lines with fibers bearing spores (black in mass). The interior if carefully sectioned would show the capitate columella, sort of an interior stipe with a ball on top. The peridium is unlike any Radiigera I have seen.

Elaphomyces have thick peridium similar to this, but usually are found in significant quantities (several hundred are possible in a small area), and are usually hypogeous where small animals dig down to them, but rarely unearth them. Once the peridium is eaten through, small animals seem to dislike the spore load/taste/fibers, or something. They typically leave the sporocarp in the bottom of animal digs or holes.

Elaphomyces are called Deer Truffles, because deer are fond of scratching them up with their antlers, and munching the sporocarps whole. Radiigera on the other hand, usually fruit as single sporocarps (rarely 2) and are much less commonly found.

Often the base of the sporocarp if examined carefully, will have a small basal pad or protuberance where the capitate columella arises from.

The peridium shown here is rather distinctive. I would venture it might well be new to science.

Created: 2015-10-12 21:04:07 PDT (-0700)
Last modified: 2015-10-12 21:27:03 PDT (-0700)
Viewed: 52 times, last viewed: 2016-10-25 21:15:34 PDT (-0700)
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