Amanita smithiana

Amanita smithiana

''Amanita smithiana'', also known as Smith's amanita, is a species of agaric found on soil in coniferous and broadleaved woodland in the Pacific Northwest of North America. It fruits in August and September.
A Young Amanita smithiana. Hopefully an educated guess. A. smithiana fruit in September to December and are found in coniferous forests. This specimen was found under a hemlock tree. Another point that limited my options is that A. magnaverrucata is not found in this area. Amanita smithiana,Canada,Fall,Geotagged

Appearance

The cap has a diameter of 5–17 cm and is white and scaled with remnants of the universal veil. The stipe is 6–18 cm long by 1–3.5 cm thick, white and similarly scaled, with a ring. Spores are ellipsoid to elongated, amyloid, and measure 11–12.5 by 7–8 µm.
Amanita smithiana ☠ Amanitas are one of the mushrooms reported to be sometimes mistaken for Tricholoma magnivelare, and I haven't previously handled one, so I pulled this one to see how it felt, smelt and what it's root looked like. I don't think if you've ever handled a real Tricholoma you'd ever make the mistake. There's no odor and it feels quite different, but if you were just going on description, it might be a misstep you could make. Amanita silvicola,Amanita smithiana,Fall,Geotagged,Kauffman's Forest Lepidella,United States

Defense

It is responsible for poisonings in the Pacific Northwest when mistaken for the edible and sought after ''Tricholoma magnivelare''. It causes initial gastrointestinal symptoms that manifest 1 to 12 hours after eating the mushrooms, followed by acute renal failure after a delay of 2–6 days. This is often severe, requiring hemodialysis, but most patients recover normal kidney function within several weeks. Gastroenteritis may result in a large loss of fluid volume. ''Amanita smithiana'' nephrotoxicity is from chlorocrotylglycine and allenic norleucine.

Several similar species have been implicated in similar cases of acute renal failure: ''A. sphaerobulbosa'', ''A. thiersii'', ''A. proxima'', and ''A. pseudoporphyria'' .

References:

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Taxonomy
KingdomFungi
DivisionBasidiomycota
ClassAgaricomycetes
OrderAgaricales
FamilyAmanitaceae
GenusAmanita
SpeciesA. smithiana