Summary:
Subgenus Validae. Amanita porphyria is distinguished by its grayish to gray brown cap (often with a purplish cast), nearly equal white or pale gray stem with a gray chevron pattern, and abrupt soft, rounded basal bulb that is often cleft vertically. Miller(14) found a small form with cap 2-3cm across along the OR and CA coasts. The English name booted Amanita has also been applied to A. cothurnata eastern in North America. A. porphyria is common in Pacific Northwest.

Cap:
3-12cm across, convex to flat or broadly umbonate; gray to grayish brown, often with slight purplish cast; usually decorated "with scattered grayish (or sometimes whitish) warts, these sometimes merging to form a patch or often wearing off or washing away", slightly viscid when moist, margin not striate or only faintly so, (Arora)

Flesh:
white (Arora)

Gills:
adnate to adnexed or free, close; "white or sometimes aging or bruising grayish", (Arora), broad (Breitenbach), numerous subgills are short, attenuate, (Lindgren)

Stem:
5-18cm x 1-1.5cm at top, equal above a large, abrupt, soft, rounded basal bulb, bulb often split vertically; white or pale gray above ring, gray or with grayish to grayish brown or purple-gray patches below the ring, (Arora), 5-12cm x 0.6-1.6cm, widening slightly downward, basal bulb rounded, marginate; stem surface with gray chevron pattern, (Lindgren), VOLVA universal veil somewhat membranous but friable, forming a collar-like volva with free rim around the top of the bulb, or leaving scattered grayish patches or disappearing, (Arora), "fragile, whitish or grayish, closely hugging the bulb and ending uniformly just short of the stem at top of rounded bulb, or ending abruptly at the top of the margin on a marginate bulb", (Goetz, D.)

Veil:
partial veil membranous, forming a superior to median, skirt-like ring that often collapses or disappears when old, ring gray or grayish yellow, (Arora)

Odor:
often turnip-like when old, (Arora), like raw potatoes (Lindgren), slight (Phillips), potato sprout or raw turnip (Goetz, D.), raw potato or radish (Trudell)

Taste:
unpleasant (Phillips), mild (Breitenbach)

Microscopic spores:
spores 7-10 microns in diameter, round, smooth, amyloid, (Arora), spores 7.6-11.7 x 7.5-11.1 microns, round, smooth, colorless; basidia 4-spored, 33-46 x 11-13 microns, clavate, without basal clamp; pleurocystidia not seen, marginal cells abundant, 20-45 x 13-24 microns, vesicular to pyriform; cap cuticle of periclinal hyphae 1.5-7 microns wide, "hyphae in the uppermost layer gelatinized and embedded in a gelatinous substance, deeper hyphae brownish-pigmented, septa without clamps", (Breitenbach)

Spore deposit:
white (Arora)

Notes:
It is reported specifically for BC (in Redhead(5)), for WA by O''Dell(1), from ID by Andrew Parker (pers. comm.), and is said to be rare in CA (Arora). Tulloss(6) examined collections from WA, OR, CA, NL, and VT. Breitenbach(4) give distribution as North America, Europe, Asia, and North Africa.

EDIBILITY

unknown (Lindgren), possibly poisonous (Lincoff)