Observation 172737: Amanita sect. Amidella

When: 2014-08-03

Collection location: St. Mihiel Woods East, Tinley Park, Illinois, USA [Click for map]

Who: Rocky Houghtby

Specimen available

Proposed Names

28% (1)
Used references: Det. by Patrick Leacock
54% (1)
Recognized by sight

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Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
Yes, there are microscopic differences and there are quite a few more species thant are…
By: R. E. Tulloss (ret)
2014-08-07 09:39:28 CDT (-0500)

listed in books. Also, book often have a picture of the wrong species with a given name. Spore measurements are useful, but not a sure thing. To get an idea of the comparisons of spore size and shape you could try this:

Go to this page on WAO:


There’s a seafoam green vertical bar on the right of all the sectional index pages. At the top of this bar clic “as sporograph.”

You will get a display of all the sporographs that we have for section Amidella. Remove everything NOT from the Americas by clickin on the “[X}” in front of a name you want to delete. These are the taxa that you should have left:

A. dolichopus nom. prov.
A. fallax nom. prov.
A. occidentalis
A. peckiana
A. pseudovolvata nom. prov.
A. sagittaria nom. prov.
A. sp-CR01 cryptonom. temp.
A. volvata
A. whetstoneae nom. prov.

The Mexican taxon “evangelinae” does not have a sporograph.

To see all the variation reported by various authors leave all the occurrences of each of these names in the list.

You may also find it useful the “Related Teaching Topic” (extreme left side of ?User+Sporograph page) entitled “Starting to use the ?User+sporograph page”.

In the case of section Amidella the above sporograph will show you how much the size and the shape of the spores of section Amidella in North America can help (or not) in separating taxa.

Very best,


By: Rocky Houghtby
2014-08-07 06:40:31 CDT (-0500)

For the input, Rod. It has been particularly cool and dry in the preceding weeks. Are there any pertinent microscopic differences between the two species?

The specimen is a little slender for volvata, but that may be due to weather.
By: R. E. Tulloss (ret)
2014-08-07 05:19:01 CDT (-0500)

The flocculence at the top of the stipe (fairly dense and thick in this case) does suggest volvata.

As time passes and DNA data begins to come in, any sense of (false) certainty about identifying species of sect. Amidella from pictures or in the field weakens.

I hope that this situation will improve. So far, I have confidence in saying, “whetstoneae” when I see its distinctive form. I hope that I’ll eventually make more progress…

Very best,


Created: 2014-08-06 22:26:16 CDT (-0500)
Last modified: 2014-08-07 05:13:09 CDT (-0500)
Viewed: 32 times, last viewed: 2017-06-18 14:08:40 CDT (-0500)
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