Observation 108945: Amanita thiersii Bas
When: 2012-09-06
No herbarium specimen

Notes: i stopped on the side of the road and took this in a hurry, so it isn’t the best shot, doesn’t include much of the stalk, but it’s a very distinctive mushroom. this one was tall, maybe 6-8 inches high, found in grassy area. just winging it with this one, unfortunately i don’t have any more photos than this.

nearby mushrooms were even bigger, also shaggy around stem and cap, their caps had flattened out.

Proposed Names

-60% (2)
Recognized by sight
-60% (2)
Recognized by sight
27% (1)
Recognized by sight

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Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
By: Cory Zanker (cz27)
2012-09-13 18:50:02 PDT (-0700)

these definitely had rough caps, so that rules out A. virosa (along w/ the location, etc.).

The first link is helpful. These were in a grassy public park (Druid Hill Park, Baltimore City), and they still line up 100% to every description of A. thiersii I’ve read, so I’m pretty convinced.

I’ll be in the Adirondacks for the first week of October, hope to upload some photos of A. Muscaria and other Amanitas.

There have been reliable reports of both A. nauseosa … [edit]
By: R. E. Tulloss (ret)
2012-09-10 14:17:16 PDT (-0700)

(backed by a dried specimen) and A. thiersii (backed by photos and spore print) from Baltimore or adjacent counties in Maryland. Amanita nauseosa was involved in a poisoning case in Baltimore. Amanita virosa has a completely smooth cap and a volva like that of A. bisporigera. Amanita virosa is very, very unlikely to occur in Baltimore because it would have had to have been imported from northern or montane Europe. That doesn’t seem to have happened very often (at least, I know of no [edit] such case in the eastern coastal plain of North America).

While the descriptions are not all equally thorough at this time, the following may be of some use to you:




Very best,


just a few here and there
By: Cory Zanker (cz27)
2012-09-07 15:37:03 PDT (-0700)

the nearest trees were about 30-40 feet away.

the description on the mushroomexpert.com site (see ref.) lines up perfectly, esp. the shagginess and the residue on surrounding grass:


i was also thinking about a. virosa, but i haven’t found a good, solid description w/ photos of that species yet, and it would have to line up nearly word for word with the a. thiersii description before i’d consider it (differences would need to be microscopic).

still, it’s surprising to see a. thiersii this far north!

no trees in the area?
By: Debbie Viess (amanitarita)
2012-09-07 09:11:42 PDT (-0700)

Created: 2012-09-06 18:38:21 PDT (-0700)
Last modified: 2012-09-14 00:59:53 PDT (-0700)
Viewed: 107 times, last viewed: 2016-10-23 21:56:34 PDT (-0700)
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