Observation 172382: Amanita sect. Vaginatae sensu Zhu L. Yang

When: 2014-08-03

Collection location: Chaplin, Connecticut, USA [Click for map]

Who: Bill (boletebill)

No specimen available

this large white Amanita with a pronounced nipple and slight striations is unusual in both sixe and color. The fruitbody is 27.5 cm. The cap is 6.5 cm. The saccate volva is 7.0 cm. The only color is a pale tan blush to the nipple on the cap.

Proposed Names

27% (1)
Recognized by sight: large all white Amanita in section vaginata

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Eye3 = Observer’s choice
Eyes3 = Current consensus


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To see what little is known about A.penetratrix,” on WAO,
By: R. E. Tulloss (ret)
2014-08-04 05:59:42 PDT (-0700)

go here:


A very cool “group” of amanitas that apparently form primordia pretty deep under ground in eastern North American forests. The hard umbo may be an adaptation useful in getting past obstacles as the cap pushes up through 12 or more cm of soil in order to be able to expand and eject spores.

Very best,


Yes, indeed.
By: R. E. Tulloss (ret)
2014-08-04 05:11:55 PDT (-0700)

I would certainly like to examine this specimen. It has been very hard for me to get useful material even though this species and similar taxa were collected at two recent COMA forays when I was present. One of these times, the power was accidentally turned off to the dyers on the last night of the foray; and I lost almost all of the “hard umbo” Vaginatae. Subsequently, there was never another year with that kind of a flush of this “taxon.” I recall that we had multiple cap colors in the flush year. I was never able to ascertain whether it was one or more species involved. I’d really like to nail that issue down.

And…you have a nice set of photos here…and you got measurements. All of that is very much appreciated.

Very best,


Correct about the hard umbo….
By: Bill (boletebill)
2014-08-04 04:02:18 PDT (-0700)

…also there is a tiny basal bulb in the bottom of the volva. I did save the specimen Rod if you’d like it.

From the soil on the stem… EDITED/CORRECTED
By: R. E. Tulloss (ret)
2014-08-03 19:47:11 PDT (-0700)

I’d guess that more than half of the stipe was inserted in the substrate. If that is the case, then this is even more like the very-hard-umbo taxon that I provisionally called “penetratrix.” The hard umbo reminded me of the perferatorium on the cap of species of Termitomyces that allows it to blast out through concrete-like termite mounds.

I see there is no dried specimen for this observation. Is that correct?

Very best,


Did you try cutting the basidiome in half (top to bottom)?
By: R. E. Tulloss (ret)
2014-08-03 19:42:26 PDT (-0700)

If so, was the flesh of the pronounced umbo very, very much harder than the other tissues?

This reminds me of collections I have (rarely) seen at COMA.

Very best,


Created: 2014-08-03 18:46:59 PDT (-0700)
Last modified: 2014-08-05 11:26:21 PDT (-0700)
Viewed: 42 times, last viewed: 2017-08-22 18:37:33 PDT (-0700)
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