Observation 50918: Tuber gibbosum Harkn.

When: 2008-05-12

Collection location: Dallas, Polk Co., Oregon, USA [Click for map]

Who: Mary Smiley (ladyflyfsh)

No specimen available

Species Lists



Proposed Names

82% (1)
Eye3 Eyes3
Recognized by sight
6% (2)
Recognized by sight: Tuber gibbosum has a much dark peridium, blending to a dark chocolate to nearly black gleba. The time this was collected and locale suggests an early Tuber oregonense to me. T. oregonense has been collected as early as August, and continuing into early February some years; Tuber gibbosum is collected as early as December and continues fruiting into the first week of July in my experience.

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

Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
Needs to be mailed directly to Matt Trappe
By: Daniel B. Wheeler (Tuberale)
2011-07-11 12:46:25 CDT (-0400)

Apparently some of the collection which were mailed to Oregon State University and the Forestry Sciences Lab have gone missing. I am not currently involved with NATS, so cannot give better information. Maybe contact NATS for better current info?

Herbarium sample
By: Mary Smiley (ladyflyfsh)
2011-07-11 12:19:28 CDT (-0400)

Daniel, Where would I send a sample to be positively ID’d and for the herbarium collection and in what condition should it be sent? I have more of these truffles from Polk County collected this year in July and want to put this silly discussion to rest once and for all. Please let me know what I need to know to get this done.

Tuber gibbosum
By: Daniel B. Wheeler (Tuberale)
2011-04-26 13:49:39 CDT (-0400)

has not been reported from Polk County in May. That doesn’t mean you didn’t find it there, only that there is no confirmed collection of that species from May in an herbarium.

The confusion is several fold. I’ll try to explain.

Gary Lincoff first wrote/edited the Audubon Field Guide. The publisher asked for common names for all species. Lincoff made some “common” names up to fill the void.

What Lincoff identified as Tuber gibbosum was collected at a North American Truffling Society forage in early December. That collection was actually a different species. The original Tuber gibbosum was described in 1898 from a collection taken in 1878 near San Francisco, and described by Dr. H. H. Harkness. The only remaining part of that original collection is a preserved slide. Scanning electron microscope examination by J Trappe confirmed the original T. gibbosum described by Harkness has a central spore depression. Under a scanning electron microscope the spores looks like a donut with a pinched center. T. oregonense has fat spindle-shaped spores. Also, T. gibbosum was collected in the spring and early summer. The differences were deemed sufficient to warrant a new name. Tuber oregonense became the new species which typically fruits during late fall through early spring. Tuber gibbosum was conserved as the name representing the later fruiting period, with a dark chocolate-brown gleba.

Your collection in May from Polk Co. is the first known from Polk County. It may be the only collection from Polk Co. currently known. A preserved voucher collection is needed.

I agree with you, Mary: this likely is Tuber gibbosum Harkness (Tuber gibbosum first described by Harkness), as T. oregonense has never been confirmed from May anywhere. But I also know Tuber gibbosum has not been identified from Polk County. Without a voucher collection, identification is supposition. Photos don’t always represent true colors.

It took me 8 years of collecting Tuber gibbosum in May, June and even July at Paul Bishop’s Tree Farm near Oregon City before Dr. James Trappe finally confirmed that Tuber gibbosum found in spring and early summer was a species separate from the so-called “fall” gibbosum, which Trappe then renamed T. oregonnese. The extremely dark gleba is one of the key identifying features for T. gibbosum in the field, as well as the spring to early summer fruiting time. Jan Lindgren collected T. gibbosum in Vancouver in December, which is the earliest known fruiting of it at this time. Until I started consistently collecting T. gibbosum in April, May, June and July, almost no one had actually seen this “spring” form, or at least described it.

Confirmation of Tuber gibbosum needs to have a preserved voucher collection. I hope you can find one. A photo of the interior would be helpful too. Currently Tuber gibbosum is known from 2 counties in California, 1 county in Washington, and 1 county (maybe 2?) in Oregon.

By: AmatoxinApocalypse (AmatoxinApocalypse)
2011-04-26 09:49:42 CDT (-0400)

I have been searching for pecan truffles for a few years now, I guess my interest in the Agaricales has taken up the majority of my time.

Pecan Truffle Info - http://www.caes.uga.edu/...

Anyways those looks great Mary, enjoy.

collection date
By: Mary Smiley (ladyflyfsh)
2011-04-26 09:08:13 CDT (-0400)

Daniel, this truffle WAS collected on May 12th 2008 and I will say it again, it is Tuber gibbosum from Polk County, OR. What do I have to do to get this named correctly?

I’m not confused
By: Mary Smiley (ladyflyfsh)
2011-01-23 18:22:56 CST (-0500)

This specimen was collected in May. I am quite certain it is Tuber gibbosum. I have also found T. gibbosum in Elkton, OR.

Now I’m really confused.
By: Daniel B. Wheeler (Tuberale)
2011-01-23 15:09:07 CST (-0500)

There appears to be a difference between the time the collection was made and the time this observation was made. If the collection was made in May, it might be T. gibbosum. If so, this would be the first collection from Polk County that I am aware of. Most T. gibbosum currently has been collected from Clark County, Washington and Clackamas County, Oregon. Undoubtedly the species is more widespread, since it was first collected near San Francisco, CA in 1878 by Harkness. There are almost no collections of this species from California, though, and very few collections from Oregon and Washington.

The time the collection was done is VERY important here.

Created: 2010-08-20 19:28:05 CDT (-0400)
Last modified: 2017-06-20 09:25:32 CDT (-0400)
Viewed: 212 times, last viewed: 2018-06-07 01:25:00 CDT (-0400)
Show Log