Observation 115967: Amanita bisporigera group

Under mixed pine and oak, closer to the pine.

KOH on the cap only turning it yellow extremely slightly – almost not at all.

Herbarium specimen in the Amanita 2012 bag. I see only one mushroom in the picture, but the bag has 3 dried Amanitas in it. They appear to be from section Phalloideae.



Proposed Names

61% (2)
Eye3 Eyes3
Recognized by sight: Rod mentions a Mexican sp. very similar to bisporigera but that yellows weakly or not at all in KOH.
Used references: Key to Species of AMANITA Section PHALLOIDEAE from North and Central America.
Based on chemical features: white amanita in sect. phalloides that weakly yellows in KOH

Please login to propose your own names and vote on existing names.

Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
Very glad you have a voucher for a KOH test with a weak result.
By: R. E. Tulloss (ret)
2012-11-06 16:46:01 PST (-0800)

In the past year, I collected material akin to A. bisporigera in the eastern U.S. that did not turn yellow in KOH…much to my surprise, because it was not one of the ellipsoid-spored taxa that don’t react with KOH, which I am familiar with. This Fall a young woman named Naomi Goldman has been doing several jobs for me incuding DNA sampling. She has been helping to build up a set of samples aimed at finding out how many genetically distinct potential or already named taxa are in my herbarium under the name A. bisporigera.

It will be great to have more Mexican material to test.

Very best,


it was quoted in that mish-mash (from my end) that got put up…
By: Debbie Viess (amanitarita)
2012-11-06 16:43:41 PST (-0800)

but not so’s you guys could see it.
thanks for doing the pull-quote mo’ bettah.

we are now on the same page.

The text you meant to quote
By: Alan Rockefeller (Alan Rockefeller)
2012-11-06 16:31:19 PST (-0800)

in the references section, I think, was "Note: At least one entity that appears nearly identical to A. bisporigera, but differs in failing to react to KOH or reacting only very weakly has been found repeatedly in the Chiricahua Mtns. of Arizona (USA) and in the neovolcanic zone of central Mexico. The typically reacting A. bisporigera is not known from Arizona. The taxonomic status of the nonreacting entity (which has never been described in detail) is undecided. "

Created: 2012-11-06 15:23:01 PST (-0800)
Last modified: 2012-11-06 16:31:36 PST (-0800)
Viewed: 56 times, last viewed: 2017-06-14 07:03:42 PDT (-0700)
Show Log