Observation 46396: Cystangium vesiculosum (Singer & A.H. Sm.) Trappe, T. Lebel & Castellano

I’ll add more info soon…

[admin – Tue Aug 17 14:06:59 +0000 2010]: Changed location name from ‘Yosemite NP, first pullout heading east along Big Oak Flat Rd.’ to ‘First pullout heading east along Big Oak Flat Rd., Yosemite National Park, California, USA

Proposed Names

-20% (3)
Recognized by sight
28% (1)
Used references: Field Guide to North American Truffles, p. 29. Not an exact match IMO. May be a species novum.

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Eye3 = Observer’s choice
Eyes3 = Current consensus


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Cystangium vesiculosa and Hymenogaster sps.
By: Daniel B. Wheeler (Tuberale)
2010-06-08 17:36:16 PDT (-0700)

I believe there are 2 species represented here. The sliced sporocarp on the left, and the upper right sporocarp both may be Cystangium vesiculosa (or a closely-related species: Cystangium still undergoing revision as far as I know); the lower, slate-gray to blue-gray sliced specimen, along with the lower right sporocarp, may be Hymenogaster sps. Both Cystangium (previously known as Martellia v.) and Hymenogaster are loculate fungi, both peridiums can wear rapidly in wet weather, but typically have a thin, felt-like peridium. I’d sure like to know what tree species they were found near. It’s possible one or more are species novum as well. Cystangium vesiculosa has a sterile base which is easily broken off unless carefully dug. There is also a small but present possibility what I am calling Cystangium is actually Gymnomyces (another branch of the hypogeous fungi previously known as Martellia). The rose staining of the peridium is fairly definitive, but I haven’t collected this and cannot be certain. May I suggest sending a dried sporocarp to Matt Trappe for identification, along with any notes of color changes you observed?

Cannot be Rhizopogon.
By: Daniel B. Wheeler (Tuberale)
2010-06-07 23:56:36 PDT (-0700)

According to Field Guide to North American Truffles, Rhizopogon means “bearded with rhizomorphs”. I can see no rhizomorphs on any specimen. There is a felt-like covering (peridium) on some of them, but it varies, not always covering the entire sporocarp. In the lower left dark-colored specimen, there appears to be a portion of reddish or pinkish material extending into the gleba about 1/3 of its length. I see something similar to this, but not extending as far, on the corresponding spot of the other dark specimen. This suggests a columella. Rhizopogon do not have columella that I am aware of.

it’s all the same
By: Noah Siegel (Noah)
2010-06-07 22:13:36 PDT (-0700)

Rhizopogon just the smaller one is more mature…

Created: 2010-06-06 22:27:25 PDT (-0700)
Last modified: 2017-01-30 13:11:59 PST (-0800)
Viewed: 123 times, last viewed: 2017-08-29 06:39:41 PDT (-0700)
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