Notes: The idea of this being Amanita simulans started on Facebook. Geoffrey Kibby posted an Amanita that looked exactly like my collection, which we in the Netherlands would call Amanita vaginata. It is assumed to be assocciated with Populus. I have included the conversation Kibby and I had that day (2014-08-07) Now my questions are:
Is A. simulans indeed an accepted taxon? If so, what should the true A. vaginata look like and what are its ecological preferences (meaning, how are these two taxa distinguished in the field)?
Kibby answers these questions to a certain level, but the Dutch mycologists (Eef Arnolds and Nico Dam for instance) are sceptical about this matter. I had a conversation over mail with Arnolds, in which he mentioned 90% of the Dutch observations of A. vaginata are found assocciated with Populus and are always more robust than the more slender and fragile collections found in our calcareous Beech forests. If A. simulans were an accepted taxon, 90% of the Dutch A. vaginata would be A. simulans, Arnolds said.
Hence, I would dive into this matter, since if it turns out to be A. simulans, A. vaginata ss.str. is a lot more rare than we initially thought and we would have a new Amanita for the Netherlands!
Here’s the conversation between Kibby and me on Facebook:
“Ted Brown brought in to Kew a wonderful collection of the rare Amanita simulans, a species that prefers Populus as its host, has a rather grey, woolly stem and a very crumbly, friable volva. This is about the third of fourth British record. He found them in Morden, Surrey.” (Kibby, 2014-08-07)
“I’ve found this under Populus today. What are the main macroscopic differences between A. simulans and the regular A. vaginata? I’ll add some more pictures.” (Beeckman, 2014-08-07)
“It is quite likely yours is simulans also, it differs in the construction of the volva, predominantly composed of large sphaerocysts as opposed to A. vaginata where there is a much higher proportion of filamentous cells, hence the volva of simulans crumbles much easier. Contu places simulans in the section ceciliae because of the friable volva, whereas vaginata is in section vaginata . Also the stem of simulans tends to have a distinctly woolly greyish-white surface.” (Kibby, 2014-08-07)
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…from Sardinia in broad-leaved forest including oak, poplar, and chestnut. Although it was said to belong in a group with A. malleata, its spores were said to be globose and only one dimension was given (which would be very unusual if it were correct). In the original description of simulans there is a photograph. In that image the stipe is heavily decorated with dark pigmented fibrils. I see there is a faintly gray decoration of the stipe here, which is darker in other observations that you recently posted (for example, 215673) and for which you suggested the name simulans.
The Vaginatae are quite difficult to determine without all the tools available to the contemporary taxonomist.
Since the volva is grayish in your photographs and apparently more submembranous, than membranous. It is plausible that this taxon has a volva somewhat similar to that of malleata or submembranacea. For this reason, I think that you are correct in not assigning your material to A. vaginata. Whatever confusion there may be about that name, it is nearly always described as having a non-graying, membranous, saccate volva.
If you have the opportunity to make a further observation of this taxon and to send me dried material of that material, I would be interested to examine it. And would post any findings
Created: 2015-09-08 01:45:15 CEST (+0200)
Last modified: 2015-09-08 01:45:34 CEST (+0200)
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