Summary:
Features include 1) a cap with a dark purplish reddish to grayish brown to dark brownish black disc and fine fibrous scales of a similar color toward the margin on a white background, the rubbed cap surface instantly staining red-orange and slowly fading to dark brown, 2) free, white gills that instantly stain orange when touched, at least on the edges, the edges darkening after being touched, 3) a hollow white stem that when touched turns first orange-red, then very dark to black, the stem surface pruinose or hairy-cobwebby over whole length, 4) a ring that is "an ascending or descending, small, white cuff, with a flaring part with fringed edge, turning dark on edge with age and touching" (Vellinga(18)), 5) a white spore deposit, and 6) dextrinoid, relatively thick-walled spores. This mushroom has been known under the name Lepiota roseifolia Murrill Mycologia 4: 235. 1912. Vellinga found the type collection of the latter species to differ from what is described here in having gills that are not dark and in having different cheilocystidia (see SIMILAR).

Gills:
free, in one to three tiers, sometimes forking or with cross walls; white, instantly staining red or orange when rubbed and then free and remote from stem, "often attached to a kind of collarium, moderately crowded to crowded", ventricose [broader in middle]; yellowish white, with white edge, "orange when touched, at least on edge, and edge darkening after being touched", (Vellinga(18)), free, in one to three tiers, sometimes forking or with cross walls; white, instantly staining red or orange when rubbed and then quickly fading to white; edges minutely fringed, (Sieger)

Stem:
5.5-7cm x 0.4-0.5cm, cylindric in upper two thirds, widening downward to 1.5cm wide base, protruding into cap, hollow; pale at top and in untouched specimens pale over whole length, when touched at first orange-red, "changing to very dark to black", "cystidiose or hairy-cobwebby over whole length", (Vellinga(18)), 4-8cm x 0.5-0.8(1.2)cm, club-shaped, stuffed becoming hollow; white, staining like the cap margin, (Sieger)

Veil:
"an ascending or descending, small, white cuff, with a flaring part with fringed edge, turning dark on edge with age and touching", (Vellinga(18)), ring persistent, flared up and folded down, white ring with a brown lower margin, (Sieger)

Odor:
"indistinct, astringent or lepiotoid", (Vellinga(18)), not remarkable (Sieger)

Taste:
unknown (Vellinga(18)), not remarkable (Sieger)

Microscopic spores:
spores in side view 5.9-8.8 x 3.5-4.9 microns, elliptic to amygdaloid-elliptic, some oblong and slightly amygdaloid [almond-shaped], in front view elliptic, [presumably smooth], dextrinoid, often with one droplet, relatively thick-walled, without germ pore; basidia 4-spored, 15-29 x 6.5-9.0 microns, narrowly clavate; pleurocystidia absent, cheilocystidia forming a continuous band or tufts, 30-93 x 8.0-14.0, "narrowly clavate, narrowly utriform, to irregularly cylindrical and narrowed into an often long pedicel, some with bifid apex, with brownish contents and some dark granules in ammonia"; cap covering is a trichoderm, toward margin more cutis-like with differentiated terminal elements 96-350 x 9.0-20 microns; cap covering "a trichoderm, toward margin more cutis-like with differentiated terminal elements", terminal elements 96-350 x 9.0-20 microns, "most often tapering toward apex, sometimes with blunt and rounded apex, in some specimens with many shorter elements, in others only with those long elements", "elements brown-walled at least in lower part, sometimes also with granulose or diffuse brown contents (in ammonia)", "repent connecting hyphae with dark granulose contents (in ammonia), sometimes also with parietal and incrusting pigments"; clamp connections absent from all tissues, (Vellinga(18)), spores 6.3-8.7(9.5) x (3.4)3.9-4.7(5.5) microns, elliptic, apiculate, thick-walled, without a germ pore, [presumably smooth], orange to dark reddish brown in Melzer''s reagent, pleurocystidia absent, cheilocystidia abundant, club-shaped and sometimes beaked; cap cuticle a "trichoderm of upright hyphae and pileocystidia on an interwoven layer", (Sieger)

Spore deposit:
white (Sieger)

Notes:
The type is from Humboldt County in northwest CA. It is presumed that this is what was reported as Lepiota roseifolia from OR (5 collections at Oregon State University) by F. Sipe and by Zeller. There are one collection from BC at the University of British Columbia and three collections from WA at Western Washington University that are labeled Lepiota roseifolia.

EDIBILITY

Synonyms and Alternate Names:
Lepiota roseifolia Murrill sensu Arora