Summary:
Subgenus Amanita. Specimens hardly break through the surface in spring and early summer after snow melt. Other features include a whitish to pale yellow, slightly viscid cap with innate, thin to cottony patches (warts), a thin, fragile annulus (ring) on the stem, a volva that is a tidy, short, thick, free-margined cup below ragged tissue on the stem, and a white spore deposit. A.H. Smith''s provisional name Amanita alpina could not be used because Amanita alpina Contu was described in 1997 (albeit not validly at that time).

Cap:
3-9cm across, convex to flat; "whitish, cream to pale yellow, not bruising"; slightly viscid, with thin to floccose [cottony] warts that are "white to tan", "margin with short striations only in extreme age"

Flesh:
white

Gills:
close to crowded, broad; white to creamy, not staining, (Lindgren), free, crowded (about 200 or more), well separated with a few short subgills or not, "rounded out, rather broad"; "white to cream"; sticky, edges white-floccose, (Cripps)

Stem:
3-9cm x 1-2.5cm at top, with rounded bulb at base that often tapers to a point; "stem partially stuffed", white; surface powdery, (Lindgren), 5-10(18)cm x 1-3cm, "equal, narrower in the middle or gradually enlarging towards base, rounding out and then often with a point at very base"; white; floccose on upper part and fibrillose on lower part, "often with torn tissue", (Cripps), VOLVA "short, free margin, not inrolled", (Lindgren), "as a tidy cup, rather thick, rimmed (or with several ''rims'' in layers), dirty white, persistent, tough, often covered with adhering soil", (Cripps)

Veil:
annulus fleeting on many, others with partial rings or ragged tissue, (Lindgren), annulus thin, fragile, white, "often as a band of tissue, easily disappearing or none (exannulate form), often with torn/ragged tissue in zones" on lower stem, (Cripps)

Odor:
not distinctive, (Lindgren), "indistinct or unpleasant to slightly fruity", (Cripps)

Microscopic spores:
spores 9-12 x 6-7.5 microns, elliptic, inamyloid, (Lindgren), spores (holotype) 9-12 x 7-8 microns, elliptic, smooth, inamyloid, colorless, thin-walled, 1-guttulate, "apiculus sublateral"; basidia 4-spored, 49-70 x 7-14 microns, clavate, sterigmata <= 7 x 1.5 microns; rare, thin clamps at the base of basidia, in other tissues not observed, (Cripps)

Spore deposit:
[presumably white]

Notes:
The original publication of the species mentions a) collections examined from ID and (including holotype) MT, b) occurrence in May in WA and ID, c) occurrence in a few places in the Pacific Northwest, and d) DNA ITS sequencing from a root tip in the Sierra Nevada of California suggesting its presence there, (Cripps). At present it is only known from a few sites in BC, WA, ID, and MT (Lindgren). A number of collections from Oregon at Oregon State University are labeled as Amanita alpina.

EDIBILITY

unknown (Lindgren(2)), likely toxic, with one report of poisoning, closely related to Amanitas such as A. muscaria that contain ibotenic acid and muscimol, (Cripps)

Synonyms and Alternate Names:
Amanita alpina A.H. Sm. nom. prov. (invalid name)