Observation 181177: Amanita bisporigera G.F. Atk.
When: 2014-09-19
No herbarium specimen

Notes: Found growing scattered in an oak and pine forested area.

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You’re welcome.
By: R. E. Tulloss (ret)
2014-12-07 15:19:59 PST (-0800)


Thank you so much for your help!
By: Dylan Moore (Dmoore444)
2014-12-07 15:04:04 PST (-0800)

Thank you so much for your help!

The yellow reaction is very common in some members of the Phalloideae and…
By: R. E. Tulloss (ret)
2014-12-06 20:07:45 PST (-0800)

not others.

The positive reactions are recorded for white capped species.

Species that are supposedly always negative in North America are the white variants of A. phalloides, A. elliptosperma, and A. magnivelaris. The postives in North America include A. bisporigera (but every once in a while i find one or hear of one that did not change…I have checked this morphologically and genetically…there are a small number of fruiting bodies of bisporigera that are KOH negative), A. ocreata, and A. suballiaceae. There are also KOH+ undescribed white species of the Phalloideae in eastern North America that turn yellow…we just confirmed another one this evening…which brings us to at least four. There are partial pages for three of these on the WAO website:


The fourth still needs to be sorted out a bit more before we create a page, but it seems that there will be another page.

I hope this helps.

Very best,


The cap turns yellow with KOH, is that typical of Phalloideae?
By: Dylan Moore (Dmoore444)
2014-12-06 18:17:24 PST (-0800)

The cap turns yellow with KOH, is that typical of Phalloideae?

Thank you,
Dylan Moore

Did you check to see if you got a color reaction from a drop of…
By: R. E. Tulloss (ret)
2014-10-02 04:57:31 PDT (-0700)

5 to 10 percent KOH (potassium hydroxide) solution on the cap?

Very best,

Rod Tulloss

The distinct cylinder of volva around the base of the stem…
By: R. E. Tulloss (ret)
2014-10-02 04:56:06 PDT (-0700)

is more typical of white Phalloideae with ellipsoid spores…such as A. elliptosperma. Did you retain the specimens? Do you have access to a microscope?

Very best,

Rod Tulloss

Created: 2014-10-01 21:46:35 PDT (-0700)
Last modified: 2014-10-01 21:46:37 PDT (-0700)
Viewed: 47 times, last viewed: 2016-10-20 13:41:53 PDT (-0700)
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