Notes:
Growing from grassy ground under/near several oaks.

Images

Faint striations on the cap margin.

Proposed Names

30% (2)
Recognized by sight: Stature, white/free gills, indistinct volva.
ret
73% (3)
Based on chemical features: distinctive nrITS and nrLSU combined length of 2000 characters
84% (1)
Based on chemical features: Unique nrDNA

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= Observer’s choice
= Current consensus

Comments

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As the sequences are prepared for deposit in GenBank, this species has been …
By: R. E. Tulloss (ret)
2020-02-09 07:56:22 PST (-0800)

gone over some more. The obconic stub of tissue below the stem base is a quite striking element. It may be the base of the volva. In the images on this page, it seems to have its own distinct coloring.

Secondly, this particular specimen (at any rate) also brought up so much of the volva onto its maturing cap that a limbus internus connected to edge of the volva’s calyptra passes under the end of the cap and cover’s the outermost ene of the gills. At leasst that is my interpretation at the moment.

We expect the completed and reviewed sequence to be posted to GB next week and available from GB within around 10 days after that. It has the dominant form of the nrLSU left hand end prefix (5’ motif) in the Vaginatae.

The sequence will be an nrITS-LSU joine sequence of about 2000 characters.

R

where is this sequence, Rod?
By: Debbie Viess (amanitarita)
2019-09-20 11:06:56 PDT (-0700)

and would you please link to it from this observation?

“velosa” was mere speculation as one of several possible white vaginate amanitas.

clearly all of the possible vaginate amanitas have not been sorted out in NA.

The derived sequences were Blasted against the GenBank database and no…
By: R. E. Tulloss (ret)
2019-09-13 07:00:41 PDT (-0700)

sequence was found with less than 1.6% genetic distance to the sequence of Amanitasp-C27”. (The closest sequences was from the A. populiphila cluster.

Because of the extensive discussion of whether this material could be assigned to Amanita velosa, we compared both genes to the available nrITS genes (five) and nrLSU gene (one) that had been identified in GenBank as having been derived from A. velosa. An image of a distance chart and an imagae of the related alignment from which the chart was derived is available from RET.

We found that the GenBank velosa nrLSU is 3.4% distant from the nrLSU of the voucher of the present observation (a very distinct species). We found that the GenBank velosa nrITS sequences had a range of distance from those of the present mushroom of 8.8-11.4% (a distant species).

Hence, it will be necessary to develop more data (e.g., spore measurements) in hopes of adding to the useful identification characters for the present species.

nrITS and nrLSU sequences hav been derived from the voucher of this observation.
By: R. E. Tulloss (ret)
2019-09-13 06:44:52 PDT (-0700)
Thanks Byrain,
By: groundhog
2015-01-13 11:49:31 PST (-0800)

We have received this material and accessioned it to Rod’s herbarium, It has been scheduled for DNA sequencing.
Thanks,
Naomi

Updated smell.
By: Byrain
2011-03-30 10:04:43 PDT (-0700)

It definitely smells fishy now.

.
By: Byrain
2011-03-29 12:56:13 PDT (-0700)

I have seen the BAMS velosa page before, but I didn’t notice the two with indistinct volva, thanks for pointing them out. And it is easy to leave the volva in the ground when digging them up (If that is what you meant?), so I usually spend a few to several minutes digging Amanitas out carefully with a knife. This one came out relatively cleanly and easily.

And either way, I am drying & saving the specimen so it can be viewed under a scope later. I recently made the plunge and ordered one online, so it shouldn’t be too long.

yes, a “normal” velosa specimen has a membranous volva…
By: Debbie Viess (amanitarita)
2011-03-29 12:29:37 PDT (-0700)

but I have left those in the ground before when digging them up; check out the BAMS velosa page, where I show two examples of a velosa with an indistinct volva, one in the group basket photo, and the other with its volva riding far up the stipe (and leaving a crumbly, non-membranous covered base):

http://bayareamushrooms.org/...

all conjecture at this point, other than it being a vaginate amanita.

Smell
By: Byrain
2011-03-29 11:55:36 PDT (-0700)

The base smells possibly faintly fishy, too soon to tell quite yet though. I left it out to see if I can enhance the smell and will update later. And wouldn’t a white A. velosa have a cup-like volva like the non-white ones in observation 64890? http://mushroomobserver.org/64890?q=3zH1
Rather then an indistinct volva as this Amanita has? (I’m certain I dug it out in one piece)

could be a white velosa.
By: Debbie Viess (amanitarita)
2011-03-29 11:44:18 PDT (-0700)

does it smell at all fishy?

It was white.
By: Byrain
2011-03-29 11:36:36 PDT (-0700)

I checked this morning when taking a picture of the cross section to see if the striations were consistent. Which they are consistently faint and it was simply white under the veil. As for staining, it doesn’t appear to be doing so, neither red or yellow.

what was the cap color under that veil?
By: Debbie Viess (amanitarita)
2011-03-29 11:26:29 PDT (-0700)

Gray? If so, this could be a protecta, with that crumbling volva at the stipe base. Has it yellowed or reddened since you collected it?