Observation 45563: Tuber aestivum Vittad.

When: 2010-05-03

Collection location: Geneva, Switzerland [Click for map]

Who: Douglas Smith (douglas)

Specimen available

Brought into the SMG meeting, and I took part of it home. It was immature without spores, so I kept it wet and dark for a week, and then looked for stuff. It was quite smelly, but not that bad. Hard to describe, fruity and musky/earthy.

The first micro-shot is of a section of the middle of the tuber at 100x in KOH. Here you can see the diffuse random hyaline interwoven hyphae, with the egg-shaped ascis embedded inside.

The second micro-shot is of an asci at 1000x in KOH. Here there are 4 spores in the asci. The spores are tan/light brown sub-globose and deeply reticulate. Apr. 20×16 um in size.

There seems to be a little confusion about the name of these. Some sources say it should be Tuber uncinatum. Some say it should be Tuber aestivum. The web source above states these are synonyms, but Index Fungorum says they are not. So, it seems that Tuber aestivum is referred to as the spring or summer truffle, and Tuber uncinatum is the winter truffle. So, because the season here, it seems that Tuber aestivum is a better name for this one.

Species Lists


Proposed Names

86% (1)
Recognized by sight
Based on microscopic features: black truffle, reticulated spores, 4 per ascis and sub-globose.

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= Observer’s choice
= Current consensus


Add Comment
Yeah, it was confusing as to which name to use…
By: Douglas Smith (douglas)
2010-05-18 12:51:58 CDT (-0400)

I thought I had the thing id’ed ok, but then I did a google search before labeling the name. Which I do each new name to make sure I have it spelled right, and then I started to get confused. I should just stop at one source.

But there is a claim that they are the same, but other sources say not… It seems that this name is sited as having a more consistent 4 spores per asci, anf the other name has 2-5 spores per asci with a larger variation of spore size. But that all might be just related to when the fungi fruits in the year.

So, until I see more sources I guess, I’ll use this name in the spring/early summer, and the other name in the fall/early winter. Works for me, for now.

not a whole lot of difference between the two species, macro or micro…
By: Debbie Viess (amanitarita)
2010-05-18 12:40:40 CDT (-0400)

other than time of fruiting (which is changing everywhere, enit?) and fragrance. T. aestivum supposedly has a much milder fragrance than does uncinatum, but your piece may have just been starting to rot, hence the stronger smell…

here’s a side by side comparison of both truffles (aestivum and uncinatum) and their spores:

Created: 2010-05-18 11:53:34 CDT (-0400)
Last modified: 2010-05-18 12:07:46 CDT (-0400)
Viewed: 161 times, last viewed: 2019-02-03 08:51:43 CST (-0500)
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