Observation 26241: Amanita augusta Bojantchev & R.M. Davis

When: 2009-10-04

Collection location: Larch Mountain, Multnomah Co., Oregon, USA [Click for map]

Who: Daniel B. Wheeler (Tuberale)

No specimen available

GILLS: Strongly upraised in off-white to slighly pink-tinted. 3 inches across (7-8cm) STIPE: 4-5 inches tall (10-13cm). Yellow band at top of stipe, quickly toning to dull cream with black glandules, staining burgundy where bruised by handling, lower 1/3 of stipe with many strong yellow scales, which continue into the swollen basal bulb (bottom 1 inch).

Proposed Names

60% (2)
Recognized by sight
61% (2)
Used references: based on yellow universal veil remnants on stipe and base of bulb. Stipe remnants apparently washed away.

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

Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
Not certain of host.
By: Daniel B. Wheeler (Tuberale)
2012-07-09 03:26:38 CEST (+0200)

That portion of Larch Mountain has some gorgeous old-growth Western hemlock and Douglas-fir, right next to young reproduction D-fir, W. hemlock and Red alder. If I had to guess, I’d say Western hemlock, as that is the predominant tree: 200+ feet tall, 10’ basal diameter, dense canopy, lots of debris on the floor. Not exactly a rainforest, but close.

this is a yucky example of franchetii…
By: Debbie Viess (amanitarita)
2012-07-09 01:42:35 CEST (+0200)

it is a member of the validae, or reddening amanitas, after all. one can often see reddish staining along the bulb, if you know to look. colors bleed.
if you had gotten a spore print, you coulda checked for amyloidity…

the bits of yellow universal veil along the swollen stipe base are also typical for this species, as is the dark brown cap (it can also be bright yellow).

what was the host tree?

most likely, this was a franchetii sensu Thiers.

Probably not Hypomyces, but
By: R. E. Tulloss (ret)
2009-10-08 17:37:55 CEST (+0200)

one of the hyphomycetes that attack slightly damp herbarium material. It’s a battle, but it really helps to dry material before they are starting to decay. Decaying areas are very hard to “kill” and keep from “reigniting.”


Revisited the specimen
By: Daniel B. Wheeler (Tuberale)
2009-10-08 16:46:58 CEST (+0200)

and promptly threw it away: long past identification stage. Widely involved with another whitish fungus (does Hypomyces chrysospermum attack Amanita too?) that had nearly mummified it.

By: Daniel B. Wheeler (Tuberale)
2009-10-06 20:01:04 CEST (+0200)

Considering this specimen had probably been through a couple of 80-90 degree days, the stain could have been the fungal equivalent of heat-stroke.

The specimen is fairly clearly post prime…
By: R. E. Tulloss (ret)
2009-10-06 18:44:07 CEST (+0200)

I’d be willing to grant that there was a partial veil at some earlier point in time.

The thing about the wine stain is a puzzle to me. I certainly don’t feel confident about putting a name on this without having a herbarium specimen;…and on top of that I don’t know franchetii sensu Thiers very well. I’ve collected it and photographed it and have material in my herbarium, but I’ve never studied it. It could be a decaying area that is not showing a normal staining reaction of the species. The black dots also probably represent some sort of invasion of the aging/decaying stipe tissue.

Another unresolvable mystery?

Very best,


A franchetii
By: Daniel B. Wheeler (Tuberale)
2009-10-06 07:21:10 CEST (+0200)

The base of the stipe plus the lower 1/3 of the stipe have that yellowish remnant similar to A. franchetii. I cannot see any indication of veil on the stipe. Other collections of A. franchetii posted here seem to show thicker stipes, and none shows the maroon or burgundy shading on the stipe. What do you think, Rod?

Given the complexity of Larch Mountain
By: Daniel B. Wheeler (Tuberale)
2009-10-05 19:18:17 CEST (+0200)

I’m not surprised by anything. At the base is the Columbia River, still with tidal influence. The top is nearly 4,000 feet elevation, but has plants, lichen, and fungi typical from the immediate Oregon coast. Old growth and very young stands flourish side-by-side. One of the few places that I expect new species from.

Given your collecting region….
By: R. E. Tulloss (ret)
2009-10-05 15:51:51 CEST (+0200)

Do you feel that A. franchetii sensu Thiers is not a possibility?


Created: 2009-10-05 05:50:45 CEST (+0200)
Last modified: 2014-11-06 22:40:12 CET (+0100)
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