Observation 35180: Tuber P. Micheli ex F.H. Wigg.

When: 2010-03-30

Collection location: North San Juan, California, USA [Click for map]

Who: Daniel Nicholson (danmadrone)

No specimen available

This is one of several Tuber sp. discoveries that haunt me. They Haunt as they are so intruiging and there is scant literature on them. Also these spp. dont fit well into the clsssic key. This one for evample is lightly violet colored! Others just dont fit the habitat description much at all.

[admin – Sat Aug 14 02:03:52 +0000 2010]: Changed location name from ‘North San Juan, CA’ to ‘North San Juan, California, USA

Species Lists



Proposed Names

74% (2)
Eye3 Eyes3
Based on microscopic features: Undeveloped (as usual)spores. So while Tuber like, I’m not absolute.

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

Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
Soccer ball spores
By: Daniel B. Wheeler (Tuberale)
2010-04-22 10:07:06 PDT (-0700)

made me take another look. There is another genus in the Tuberales that is found in desert and semi-desert areas. Typically covered with fine flour sand which I could never clean off completely. Assuming this obs. has not been washed, it would still be Tuber. With fine sand and pubescence on the peridium, Terfezia becomes a possibility as well.

Microscopic characteristics
By: Daniel Nicholson (danmadrone)
2010-04-22 08:19:11 PDT (-0700)

Hi Dimitar- I wanted to get another look at it under the scope but too busy. I saw asci with spores. And in the squash mount some undeveloped spores with the soccer ball look developing as a tuber should. Enough I think, for us to go with Tuber sp.

Venae externae and venae internae
By: Daniel B. Wheeler (Tuberale)
2010-04-04 16:46:07 PDT (-0700)

both present in photo 82164. Slightly odd, blown-up photo shows non-solid gleba, but with some irregular chambers still present. V. ex. and V. int. means nearly 100% Tuber species, even without mature spores. Chambers still present in gleba suggests this is a morphologically early form of Tuber, at least in the sense of Gilkey in her 1916 “A Revision of the Tuberales of California”.

in lieu of more micro information…
By: Debbie Viess (amanitarita)
2010-04-04 15:37:45 PDT (-0700)

and considering the marbled context, Tuber is a reasonable best guess. Dan did say that his ID at this point was unsure.

Here in the MO world, a wrong Tuber ID is way better than a lost in the giant mush-pile Fungi ID!

I added my vote for Tuber as “could be,” to reflect the current ID uncertainty.

Why Tuber?
By: Dimitar Bojantchev (dimitar)
2010-04-04 14:38:05 PDT (-0700)

Dan, was it an ascomycete? What microscopic features did you see to suggest Tuber sp.? It is an interesting collection though – even with immature specimen there is plenty to go on and drill down closer to a realistic name.

no spores, and habitat correction
By: Daniel Nicholson (danmadrone)
2010-03-31 19:53:10 PDT (-0700)

Correction on habitat…there is no cistus, just Cytisus scoparius- scotch broom. Late night notes are not so good sometimes.

Hey there Alan. My understanding is without spores it is relatively useless (??). I guess theres always DNA…but not for me.

By: Alan Rockefeller (Alan Rockefeller)
2010-03-31 15:34:40 PDT (-0700)

Hi Daniel

It was cool seeing you at the mssf fungus fair this year.

I find very similar mushrooms under coast live oak.

It would really help to have some microscopy. If you mail me a dried one I can take some pictures for you.

Cistus, madrone, Pinus
By: Daniel B. Wheeler (Tuberale)
2010-03-31 10:01:06 PDT (-0700)

are all known to host hypogeous fungi. Cistus (rockrose) hosts Terfezia truffles in northern Africa; madrone has some interesting and rarely collected species; and Pinus appears to be the most widelyspread Tuber host world-wide.

Also, size is not a function of maturity, although the larger specimens do tend to be more mature, probably because many small specimens are discarded as being too much work to clean.

Alnus and Salix are 2 other interesting host trees to me. I frequently find Alpova diplophloeus with Alnus rubra; and Tuber has been reported with Salix on Pike’s Peak at 12,000 feet, I believe.

I will keep looking…and pulling the weeds
By: Daniel Nicholson (danmadrone)
2010-03-31 09:19:44 PDT (-0700)

Thanks for your input Daniel W. I’ll keep on looking for more Tuber and look later in season. The Quercus kellogii seems to be a good host tree indeed. As professional gardener, i dig often in the forest edge. And I find Tuber several times a year at home and work (even after moving.) So i look forward to seeing the violet tuber again! We do see Tuber (other finds FYI) with other oak sp., Pinus ponderosa, and of course Doug Fir.

Keep looking.
By: Daniel B. Wheeler (Tuberale)
2010-03-31 07:45:10 PDT (-0700)

Most Tuber sp. have a specific time-frame where they are mature in. Dr. James Trappe has stated it may require 9 months for Tubers to mature. Your material I would judge to be within 2 months of maturity at this time, so the next 2 months are especially important for collections. Mature spores in immature Tuber collections often found near the peridium, especially where a darker color. Insect predation also a strong sign of maturity: some hypogeous fungi may have strong insect/spore dispersal interactions.

That strengthens the chance for a sp. nov.
By: Daniel B. Wheeler (Tuberale)
2010-03-31 07:39:44 PDT (-0700)

Q. kellogii strongly suspected of being tuberculate mycorrhizae.

Scotchbroom and gorse also known to be mycorrhizal, and could be potential hosts. Currently known to associate with members of the Endogonaceae.

Not much Q. kellogii in Oregon, so your material not often collected nor even searched near here in Oregon.

The reddening peridium, I presume blushing with handling, plus the violet gleba even when immature, strongly implicates a sp. nov. to me.

By: Daniel Nicholson (danmadrone)
2010-03-30 23:44:26 PDT (-0700)

Hi, there is Quercus kellogii 60-80ft…the likely host. Beyond that there was distant Arbutus. In the direct zone only rubus and cistus (I dont think likely host plants). Spores found to be immature so far.

Please replace your photos.
By: Daniel B. Wheeler (Tuberale)
2010-03-30 23:15:45 PDT (-0700)

While they are present on the observation site, they are not on the search site.

I agree this appears to be a Tuber. I further agree it is not a Tuber species known to me. Don’t feel haunted by this: it is exciting!

What part of the habitat don’t they fit? What trees and shrubs were nearby?

Created: 2010-03-30 19:54:01 PDT (-0700)
Last modified: 2011-09-29 16:28:33 PDT (-0700)
Viewed: 613 times, last viewed: 2019-01-03 17:08:31 PST (-0800)
Show Log