Observation 207717: Amanita sect. Vaginatae sensu Zhu L. Yang
When: 2015-06-25
Who: guli

Notes: Small Amanita found growing out of a lawn under several oaks. Volva is sac-like and there is no bulb at base of stem. No annulus seen. Spore print white. Odor indistinct.

Images

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DSC_0379_A.jpg
Quarter for scale. Leaf from nearby oak.
531493
DSC_0391_A.jpg
531497
2015-06-25 09.11.02.jpg
531719
2015-06-26 08.54.11.jpg
Young specimen — cap gray (not brown); no annulus seen (although A. pachysperma should have a delicate annulus?)

Proposed Names

-25% (1)
Recognized by sight: Sac-like volva, free gills, no bulb at base
-29% (2)
Recognized by sight: Small size and gray cap suggest A. pachysperma

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Eye3 = Observer’s choice
Eyes3 = Current consensus

Comments

Add Comment
While I know something about pachysperma, I’m not sure if I know much…
By: R. E. Tulloss (ret)
2015-06-26 12:29:12 EDT (-0400)

about your species of Vaginatae. I see you have preserved material from this observation. If you would be willing to share a part of the collection so that we could check it as to its DNA, I would very much appreciate it. You can contact me off-line via the MO email capability.

Very best,

Rod

Thanks! Looks like there’s no ring.
By: guli
2015-06-26 11:33:51 EDT (-0400)

Two young specimens I collected today didn’t have any ring, so probably not pachysperma. I think the caps in the image were pale with a dark center when I collected them; they might have darkened after drying a bit. I’ll check out the microscopic features once I have access to a microscope.

Thanks for the information!

The younger specimens should have a ring on the stem…
By: R. E. Tulloss (ret)
2015-06-26 10:52:28 EDT (-0400)

…if this is pachysperma. Amanita pachysperma is a member of section Caesareae. It is also (usually) rather small.

I think that this species is more likely to belong in section Vaginatae.

If you have a microscope, there are a lot of things that you could check beginning with the spore size and shape (length/width ratio) and the presence of two-spored basidia and clamps at the basis of the basidia. Details are on the page you cited above:

http://www.amanitaceae.org?Amanita%20pachysperma

on the technical tab.

Also, pachysperma can be very dark in the center of the cap, but most of the cap is a paler gray.

Very best,

Rod

Created: 2015-06-25 22:05:44 EDT (-0400)
Last modified: 2015-06-26 12:25:01 EDT (-0400)
Viewed: 65 times, last viewed: 2016-07-09 16:07:12 EDT (-0400)
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