Observation 105878: Hydnotrya tulasnei (Berk.) Berk. & Broome
When: 2012-08-16
Herbarium specimen reported
0 Sequences

under Lodgepole Pine at 7,300’.
collected by Mike McCurdy and son.


Houston, we have an Asco (but apparently not a Tuber)!
Truffle exterior: very finely tomentose.
Truffle interior.
Truffle spores, 400x, inamyloid in Meltzers, in long asci.
Spores large, round, 30-33 microns, complete reticulum.
spores enlarged for detail; hard to typify the ornamentation. maybe densely warted?

Proposed Names

-57% (1)
Recognized by sight: compressed and convoluted reddish context; smooth, convoluted reddish exterior.
Based on microscopic features: ascospores; round, heavily reticulated, non-amyloid, 30-33 microns.
Based on chemical features: fungal odor, somewhat fruity with a hint of pencil eraser!
taste, pencil eraser and fungal. texture: crumbly.
29% (1)
Recognized by sight: one of the asco truffles; genus unknown. convoluted, reddish finely tomentose exterior (observed with handlens); interior also reddish, heavily folded with narrow chanmbers.
Based on microscopic features: asci long and narrow, not rounded; spores round, heavily ornamented, around 30 microns, all parts inamyloid.
31% (2)
Recognized by sight
Used references: Gilkey, Helen M. 1939. Tuberales of North America. Oregon State Monographs No. 1, Oregon State College, Corvallis, OR. 63p. **PLATE 1, spore #7 vs spore #14
7% (3)
Used references: Field Guide to North American Truffles, p. 39
75% (2)
Eye3 Eyes3
Recognized by sight: MO would NOT allow me to add the c.f. designation here. In other words, this is NOT tulasnei but something very similar to it. name SHOULD read Hydnotrya c.f. tulasnei.
27% (1)
Recognized by sight: asci with monoseriate spores (wider asci in tulasnei)

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

Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
Still think
By: Irene Andersson (irenea)
2012-09-17 02:57:17 CDT (-0400)

it could be H. bailii – smaller spores than tulasnei and growing with conifers

Here is a list of trees
By: Mike McCurdy (lesmcurdy)
2012-09-17 02:00:55 CDT (-0400)

within a 60 ft. radius of the location this truffle was collected. Also, the truffle was found directly next to a large exposed boulder appox. 45 ft. long by 20 ft. wide, and 7 ft. high. This applies to MO observation 107010 as well.

Less than 20 ft.: 8 lodgepole pine, 2 red fir.
20 to 40 ft.: 14 lodgepole pine, 11 red fir.
40 to 60 ft.: 17 lodgepole pine, 5 red fir, 1 western white pine.

By: Mike McCurdy (lesmcurdy)
2012-09-09 03:36:35 CDT (-0400)

I’ll be in that area in the next couple of weeks, and can do a more precise job of describing the surrounding trees, and will comment with the findings.

The following week I attempted to find more of the same at the same location. I first checked beneath the duff, then dug to a depth of 5" to 6" over an area roughly 7.5 sq. ft. None of this variety were found, but I did find another variety (posted on MO # 107010), which is currently labeled simply Basidiomycota, found approx. 12" from the first truffle.

collecting potential host associations
By: Michael Castellano (trufflercaz)
2012-09-07 14:50:04 CDT (-0400)


We usually list all the nearby tree hosts for colelctions not just the nearest. mycorrhizal roots and associated fungal mycelium can extended very far. A good rule of thumb to use is list all trees within the distance that the average tree height is in the area.

thanks again.

confirmed Hydnotrya tulasnei
By: Michael Castellano (trufflercaz)
2012-09-07 14:47:43 CDT (-0400)


I studied the half specimen you sent. Thank you. I have assigned number T35936 for it and it will be accessioned into the OSC herbarium over time.

Nice find, send me more truffles from that neck of the woods. Very little is known of the truffles on the El Dorado National Forest and that area in general.

It is always helpful to have good quality macro photos to add in identification.


It was not growing
By: Mike McCurdy (lesmcurdy)
2012-08-20 13:34:05 CDT (-0400)

on or near an obvious piece of rotting wood. It was found 3" to 4" below the surface, in a mixed conifer forest. The closest trees were lodgepole pine.

let’s be patient on this ID…
By: Debbie Viess (amanitarita)
2012-08-20 13:26:05 CDT (-0400)

determining the exact nature of both the peridium and the spores was quite difficult, for reasons that I have already discussed here.

Once Michael gets this fruit body in hand, I am sure that he will post his findings.

Debbie notes under suggestion Ascomycotina
By: Daniel B. Wheeler (Tuberale)
2012-08-20 13:18:48 CDT (-0400)

this obs. has tomentose peridium. Does Hydnotrya have tomentose peridium, Michael? I can find nothing on it.

52 collections
By: Daniel B. Wheeler (Tuberale)
2012-08-20 13:16:51 CDT (-0400)

certainly exceeds my single collection, Michael.

I have multiple collections of G. cerebriformis which have filled internal spaces from Paul Bishop’s Jones Creek Tree Farm at OSU Herbarium. The closer I collected G. cerebriformis to June, the more filled the sporocarps are.

C.f. (or cf?) stands for close in form? Something new I have learned today. Thank you!

some additional clarification
By: Michael Castellano (trufflercaz)
2012-08-20 12:15:48 CDT (-0400)

Dan – i have 52 collections of tulasnei in my herbarium with elevation ranges from near sea level to at least 7200 feet, elevation is a poor indicator for some species while for others like Thaxterogaster pinquis it really narrows the elevational range to expect it in.

The other thing is notice I listed it as cf which is an indicator that it is close in form. there are a number of species in Hydnotrya with this compact gleba form that have the color tones inferred from the pictures.

H. inordinata and H. subnix which I describe with trappe are two such species with a more or less solid gleba and they are also found at high elevation but very uncommonly.

For now best to assign Hydnotrya cf tulasnei until after i have the specimen in hand to put a species name on it.

hope this helps.

I see now that Michael (caz) has joined out merry group. Welcome!
By: Daniel B. Wheeler (Tuberale)
2012-08-20 11:51:15 CDT (-0400)

Hydnotrya often has flaps of tissue overlaying the outer sporocarp (see the flap on the right-hand side of the obs photo)? I have collected Hydnotrya tulasnei at my family’s tree farm (Shepard Place) between Lebanon and Brownsville at perhaps 600-800 feet elevation, with Willamette Valley Ponderosa pine. It had few similarities with this obs. taken from 7300’ elevation. Also there is no mention of well-rotted wood associated with the sporocarp, which makes me question that identification. My collection was found fruiting within or extremely close to a well-rotted limb as I recall. According to Field Guide, H. tulasnei should have spores “…irregularly globose but appearing angular when tightly packed together in asci …” The ascii here do not appear to me to be “tightly packed”.

By: Debbie Viess (amanitarita)
2012-08-20 11:36:31 CDT (-0400)

not you, Michael.

apparently messages are hopscotching each other in this quasi-dialogue!

I’m rather surprised
By: Daniel B. Wheeler (Tuberale)
2012-08-20 11:36:30 CDT (-0400)

no one suggested Hydnotrya, which also has the same general overall appearance as this obs, with hollow chambers filling with maturity. Fortunately Hydnotrya are so often associated with well-degrading wood they are sometimes called “wood truffles.” Many have squarish spore shapes (H. cubispora) which are completely unlike any other truffle in my experience.

Sorry, few photos of any sporocarps Debbie. Not a frequently collected species. Often the sporocarp is so small many people overlook it. Brittle nature is something I should have included. When these break apart into smaller sphere-like structures, it is sometimes difficult to believe they were once part of a larger whole. While not enough data has been compiled for general size at different altitudes, the low-elevation material tends to be much larger than the high-altitude collections I believe. I have not collected it often, although I found it several years running at Paul Bishop’s Tree Farm in the late 1980s, where it was associated with a single Douglas-fir on the perimeter of a plantation near his gate. (The gate helped me remember where to look for it.)

I agree: there could have been mention of the color changes in the description that would be helpful. I’m not certain Drs. Trappe had enough collections to work with, though. G. cerebriformis is often collected while still immature, making identification unlikely if not impossible without mature spores.

was this last comment directed to me?
By: Michael Castellano (trufflercaz)
2012-08-20 11:34:00 CDT (-0400)


not sure if your last comment was directed to me but coloration changes with age and your specimen looks old and often specimens from different substarte, decayed wood or soil can have varying color ranges.

I am confident it is not Genabea I have collected Genabea cerebriformis numerous times and the hollow nature of the sporocarps NEVER varies and in fact the sporocarps often crumble when handled roughly. Hydnotrya species are much more pliable and the variiformis group is always with a large central hollow cavity but the Hydnotrya tulasnei group which includes H. cubispora and some undescribed taxa in my herbarium have a more solid looking convoluted interior.

hope that helps.


got photos of other mature specimens, Daniel?
By: Debbie Viess (amanitarita)
2012-08-20 11:22:46 CDT (-0400)

it is kinda hard to believe that this is the same mushroom as depicted in the little truffle book. quite the color and morphology changes over time. woulda been nice if the descriptions mentioned it.

do Genabea sp. have elongated asci?

brittle texture and spores are a good match. color and context not so much. size not so good either: this fruit body was way bigger than “width rarely more than 1 cm” as quoted for the NA Truffle Book.

as to peridium texture…really hard to see much of anything, even w/using a handlens and a little scope. at most I saw a vague fuzziness, from very short stiff hairs, not a warty texture, though. the fact that it was covered in crumbled granite bits, even after brushing off, also made it tough to get a feel for texture.

Hydnotrya cf. tulasnei
By: Michael Castellano (trufflercaz)
2012-08-20 11:18:24 CDT (-0400)


the reddish brown coloration and compact infolding of the glea points to Hydnotrya. Genabea always have distinct cavities that are hollow.

The spores of genabea are also spiny and these you report as reticulate.

Send me a piece and I will confirm.

Please include all collection data so I can assign a herbarium number to it and accession it into my herbarium.

nice find as it is rather uncommon.


michael castellano

Debbie, re. Tuber
By: Daniel B. Wheeler (Tuberale)
2012-08-20 11:17:01 CDT (-0400)

not a bad guess. Tuber differs from Genabea in having both venae externae (external veins) and venae internae (internal veins), both of which are typically composed of sterile tissue, usually a lighter color than the surrounding sporocarp. Think of a high-altitude photo showing waterways in lighter colors.

Many of the more rare Genabea associated with forbes in summer and early fall, which is one reason they are not frequently collected, as few people expect to find them in those situations. They are often tiny. Calling the average 6mm may be generous.

Matches in all respects.
By: Daniel B. Wheeler (Tuberale)
2012-08-20 11:10:23 CDT (-0400)

Highly reticulated spores 30-33 microns perfect. This is a VERY mature specimen. Usually I find it with Douglas-fir in the late spring (May). Photo in Field Guide to North American Truffles is rather immature yet. G. cerebriformis has hollow chambers that fill in age, much like Barrsia oregonensis is hollow until nearing maturity. Field Guide also notes the “grayish-yellow” color, small size (I don’t think I’ve ever collected it over 6cm diameter), and association with Pinus. G. spinispora associated with forbes, I believe. Like Genea, Genabea often has hollow chambers when young that fill in maturity. While difficult to tell it should also have minute warts on the peridium. Field Guide gives the spores as “29-34 microns, globose, with densely crowded spines 2-3 microns tall.” Found from March thru October with pine, Douglas-fir and oak.

it is not G. cerebriformis either…
By: Debbie Viess (amanitarita)
2012-08-19 13:01:41 CDT (-0400)

which has a whitish exterior and whitish, hollow chambers inside.

According to the 1962 Mycologia link that you provided, G. spinospora has white fruit bodies averaging 6 mm in diameter!!! (can that even be right?) also, the spores have “uncrowded” spines, even if the spore size is within range of this sighting.

not there yet.

more info
By: Darvin DeShazer (darv)
2012-08-19 12:53:09 CDT (-0400)

Found the original description of Genabea spinospora in Mycologia.

http://www.cybertruffle.org.uk/cyberliber/59350/0053/003/0215.htm and spores are 26-32 µm. Genabea sphaerospora is elimenated based on spore size ~20 µm.

Spores are densely spiny
By: Darvin DeShazer (darv)
2012-08-19 12:28:50 CDT (-0400)

I suspect it’s Genabea cerebriformis because it’s very common, but still looking for info on Genabea sphaerospora and Genabea spinospora to see if they fit.

some sp. of Genabea certainly have similar round spores…
By: Debbie Viess (amanitarita)
2012-08-19 12:13:26 CDT (-0400)


no word on whether they are borne in sacs or elongated asci, though.
and the macro of the three sp. of Genebea that I found was not a good match.

so Darv, do you think that the spore ornamentation is more thickly packed warts than a complete reticulum? Is a reticulum more open? It is hard to see just what is going on, and when you compare the micrographs with electron micrographs it gets really confusing, like for this species of Genabea with ellipsoid spores:


as per Darvin DeShazer…
By: Debbie Viess (amanitarita)
2012-08-18 18:07:36 CDT (-0400)

Tuber asci are rounded; these are elongated. therefore, this is not a Tuber but it is an ascomycete, genus unknown.

Created: 2012-08-18 15:16:48 CDT (-0400)
Last modified: 2012-09-09 04:35:01 CDT (-0400)
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