Observation 115649: Leucangium carthusianum (Tul. & C. Tul.) Paol.

When: 2012-11-03

Collection location: Mount Pisgah Arboretum, Lane Co., Oregon, USA [Click for map]

Who: David Rust (incredulis)

No specimen available

Identified by Toby Esthay. Part of display at Cascade Mycological Society mushroom festival.

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all that for a “nearly?” really?
By: Debbie Viess (amanitarita)
2012-11-04 13:26:01 -05 (-0500)

there were plenty of experienced folks on the ground to recognize this species.
nuff said.

Truffle book
By: Daniel B. Wheeler (Tuberale)
2012-11-04 13:07:53 -05 (-0500)

says “Peridium charcoal black and warty, but sometimes nearly smooth.” Nearly smooth is not the same as smooth. For this to be Leucangium carthusianum black warts are required. The book also says “Gleba solid and firm, with gray pockets of spore-bearing tissue separated by white veins.” There are no “gray pockets” present here and no white veins here. I have dried L. carthusianum at home. Even exceptionally mature material, which is nearly black in the gleba, still has easily visible white veins.

Leucangium carthusianum has been found nearly year-round now. I’ve spoken to 2 different truffle hunters who assure me they have found L. carthusianum every months. That is not mentioned in the Field Guide. Late summer/early fall is not an abundant fruiting period for this species. They are usually very young. Young specimens can have a nearly white gleba, but still with have veins present.

One year I took Tuber magnatum fresh from Italy to the Mt. Pisgah show. NO one identified it. The most famous truffle in the world! That included several “experts” from the Forestry Sciences Lab at OSU. I remember Dan Luoma and Michael Amaranthus were present. I think Matt Trappe was there as well, but Dr. Jim was in Australia.

I think the reason the Field Guide said “nearly smooth” is that Leucangium brunneum was also listed there. At the time, L. brunneum was a new species. It has now been given its own genus, Kalapuya brunnea. While the Field Guide says of K. brunnea “granular to warty”, it has a nearly smooth peridium. I remember at the time of publication, this was something of a bone of contention. By transferring it to Kalapuya, the contention has been eliminated. For a time.

Even experts have trouble with these. I remember the first time Zelda Carter, then president of NATS, brought in fresh K. brunnea to the Truffle Dinner. I urged her to have Dr. Jim check the truffle before serving her excellent dish. Dr. Jim merely commented it was a good idea to provide a voucher collection for any species novum before serving it to guests.

The photo is slightly out of focus. But even when enlarged to huge, no veins or warts are visible.

photo quality here is kinda poor to see details.
By: Debbie Viess (amanitarita)
2012-11-04 11:43:32 -05 (-0500)

however, we did have on the ground verification of truffle species by Matt Trappe, who was at the Fair on Saturday. the Trappe truffle book claims that the peridium CAN be smooth in this sp.

Beyond that…nothing got saved (other than the very few things that I took home with me).

We had a whole collection of Oregon black truffles there, and quite a few accomplished truffle hounds in human form.

There are many things this could be.
By: Daniel B. Wheeler (Tuberale)
2012-11-04 02:14:09 -05 (-0500)

Leucangium carthusianum is not one of them.

In Leucangium carthusianum, the peridium (outer portion) has charcoal-black warts. This obs. has none.

In Leucangium carthusianum, especially in the young material, there should be white veination. There is none here.

Melanogaster is possible here, but not likely either. The peridium of most Melanogasters is reddish when fresh, not black usually.

Alpova trappei is possible, but rarely collected. It should has a gelatinous gleba.

Rhizopogon ater is also possible, but also rarely collected. It has a loculate gleba (interior with small chambers).

There is not enough detail in the photo for me to guess at what it actually is. Rhizopogon ater has been found mature in November, and it would have rhizomorphs on the peridium. It should also have silver elements within the gleba, not unlike the warf and woof pattern on fabric, crosshatching the gleba under magnification.

Created: 2012-11-03 22:50:50 -05 (-0500)
Last modified: 2012-11-04 13:26:08 -05 (-0500)
Viewed: 124 times, last viewed: 2018-04-20 10:36:29 -05 (-0500)
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