Observation 69973: Amanita rhopalopus Bas

When: 2011-06-22

Collection location: Long Hunter State Park, Davidson Co., Tennessee, USA [Click for map]

Who: Brian Adamo (adamo588)

No specimen available

6.5cm diameter cap, 8cm long rooted stem, pale yellow gills, chlorine odor, growing in the middle of a trail in mixed forest. I hope whatever took a bite out of it is feeling better.

Proposed Names

44% (2)
Recognized by sight

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Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
Almost forgot…
By: R. E. Tulloss (ret)
2011-06-24 16:34:03 EDT (-0400)

The pictures are good and show lots of diagnostic characters. They were extremely helpful in trying to go through the process of elimination.


You’re welcome
By: R. E. Tulloss (ret)
2011-06-24 16:32:26 EDT (-0400)

Damned if I’m gonna punch out with all this stuff locked away in my deteriorating brain.

Another thing that might be useful in reading fungal names ending in -pus or -pes

rhopalo- pus is “club- foot” (Greek word roots)

longi- pes is “long- foot/leg” (Latin word roots)


Thanks, Rod
By: Brian Adamo (adamo588)
2011-06-24 16:15:58 EDT (-0400)

Your comments are always very educational and most welcome. This name will be easy to remember – I’ll just think of Muhammad Ali’s Rope-A-Dope !

Getting closer to a name…
By: R. E. Tulloss (ret)
2011-06-24 11:39:20 EDT (-0400)

Dog-legged bulb on the stem base that is abrupt or semiabrupt (quick change in diameter from stipe diameter above bulb), flocculent ring getting raggedy rather quickly, flocculent white warts (not striate on the sides and not having a distinct base that has a different appearance from the pyramid above it), lack of recurved scales around the top of the bulb, lack of a little membranous limb at the top of the bulb, lacks the usual colors and habit and geography of species of subsection Gymnopodae… So what’s it not? not in subsection Vittadiniae, not in subsection Limbatulae…hence, in subsection Solitariae.

That’s a big subsection. On we go…

Eliminate Bas’ stirpes having no representative east of the Rockies in North America: Crassiconus, Eriophora, Grossa, Perpasta, Silvicola, Straminea, Virginea, Virgineoides, and Xanthogala.

Not in stirps Solitaria (eliminate cokeri and “subcokeri”).

By the habit of the fruiting body, we can eliminate polypyramis.

Not in a stirps with universal veil so disorderly as to largely prevent wart formation (eliminates stirpes Chlorinosma and Longipes)

Not in any stirps containing taxa with volva pigmented from the outset (eliminates atkinsoniana, cinereoconia, cinereopannosa, microlepis, onusta, pelioma, westii)

Among the remaining taxa, A. abrupta can be eliminated (finishing off the candidate taxa in stirps Microlepis).

The absence of staining in the fruiting body and the lumpy warts suggest that daucipes is not an option. The apparently viscid cap surface eliminates rhoadsii which lacks a gelatinizing pileipellis. The form of the warts eliminates ravenelii. There is one other species in stirps Rhoadsii (subsolitaria), which normally is found in the Coastal Plain, has a slightly different habit (e.g., not so slender), usually has different warts (cake like or pyramidal), has a curious odor that is not like the “chlorine”-group of odors and has gills that are more intensely cream-yellow.

This leaves stirps Rhopalopus with two members on the east coast. “_Amanita magniradix” has an extremely long radicating bulb and, hence, is not what we have here.

It appears that a probable determination for this mushroom is A. rhopalopus.


Created: 2011-06-23 16:39:08 EDT (-0400)
Last modified: 2011-06-24 11:51:03 EDT (-0400)
Viewed: 64 times, last viewed: 2017-09-09 19:17:05 EDT (-0400)
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