Summary:
Important field marks are 1) a cap that is whitish or tinged either grayish or buff, 2) free, close, white gills that become pinkish or grayish vinaceous, 3) a white stem slightly pruinose in its upper part but otherwise bald to silky, often discoloring yellowish or brownish, 4) a membranous ring that is persistent and may be movable, 5) growth particularly in grassy areas, and 6) a white spore deposit. Hansen, L.(2) consider it a synonym of Leucoagaricus cretaceus (Bull.: Fr.) Moser. Leucoagaricus leucothites is common in the Pacific Northwest and widespread in the United States in general.

Cap:
4-10(15)cm across, ovoid to nearly spherical when young, then broadly convex to flat; "typically dull white but at times gray, buff, or creamy, the center sometimes tinged pinkish-buff", "one form staining yellow when handled, another brown"; dry, usually smooth, but sometimes with numerous small bran-like particles, or becoming scaly when old, (Arora), 4-8(12)cm across, nearly spherical to ovoid when young becoming convex or with slight obtuse umbo; "usually smoky gray over the disc, white to dull white or sometimes tinged very pale buff elsewhere when young"; unpolished to appressed-fibrillose, "smooth or only rarely broken up into scales", "the margin usually fibrillose-tomentose", (Smith, H.V.), 3-10cm, convex becoming flat and uplifted, margin incurved becoming flat; either light gray or whitish; with a suede-like feel, disc smooth, margin smooth or occasionally with small appressed scales that may reveal white flesh when old, (Sieger), nearly always white or whitish at maturity (buttons may be tinged pale gray), (Smith(15))

Flesh:
thick; white, not bruising, (Arora), thick, rather firm; white, (Smith, H.V.)

Gills:
free, close; white, but often buff, pinkish, or grayish pink when old, and finally brownish, (Arora), approximate to stem at first, becoming more distant from it when old, crowded, broad, broadest near cap margin; "white at first, slowly changing to sordid grayish vinaceous, when dried dingy vinaceous brown to dark avellaneous"; "edges slightly floccose", (Smith, H.V.), free, close, in one to three tiers, occasionally branched, with cross walls, or both near stem; "whitish becoming dark when dried"; "edges even or minutely fringed", (Sieger)

Stem:
5-15cm x 0.5-1.5cm, equal or with widened base; white, "sometimes staining yellow when bruised, and usually discoloring brownish in age or upon handling"; dry, without scales, (Arora), (5)7-12(15)cm x (0.5)0.6-1.2(1.8)cm at top, equal or slightly widened at base, stuffed then soon hollow; white; bald to silky below the ring, slightly pruinose above the ring, (Smith, H.V.), 4.5-14cm x 0.5-2cm, usually club-shaped with widened base, rarely even; white, slowly darkening or staining yellow where handled, stuffed becoming hollow; smooth, the base often with cottony fibers, (Sieger), whitish to grayish brown, may discolor yellowish or pinkish, (Trudell)

Veil:
"membranous, white, forming a distinct, persistent, superior, double-edged, collarlike or sleevelike ring" which is usually movable when old and may fall off, (Arora), ring "persistent, membranous, often collar-like around the stipe and flaring above the collar, edge double, thick, white, cottony-floccose, upper surface white and silky, lower surface pallid buff at or near the margin", (Smith, H.V.), ring thick, persistent, becomes movable, upper part flares like a collar, lower part hangs like a skirt; edge frayed, lower surface may have patches; whitish, underside brown near margin, (Sieger)

Odor:
mild, or in one form unpleasant, (Arora), slight, not distinctive, (Smith, H.V.), not remarkable (Sieger)

Taste:
mild (Smith, H.V.), not remarkable (Sieger)

Microscopic spores:
spores 7-9 x 5-6 microns, elliptic, smooth, dextrinoid, thick-walled, with apical germ pore, (Arora), spores 7-9 x 5-6 microns, suboval, rusty brown in Melzer''s reagent, with large oil droplet, "walls thick, with a small apical lens-shaped plate"; basidia 4-spored, 28-32 x 8-9.5 microns, colorless in KOH; pleurocystidia absent, cheilocystidia abundant, 28-39(44) x 7-12 microns, "some slightly fusoid-ventricose with obtuse apices, some clavate to saccate", colorless in KOH; no well-defined cap pellicle formed, some slightly enlarged hyphal cells 80-100 x 7-10 microns (usually tapered slightly to obtuse apex) present as occasional pileocystidia, (Smith, H.V.), spores 7.9-10.3(12.7) x 5.5-6.3 microns, oval and symmetric in side view, pale to dark reddish brown in Melzer''s reagent, thick-walled with germ pore; pleurocystidia absent, cheilocystidia clavate to ventricose; cap cuticle "short upright hyphae with elongate tip cells arising from an interwoven layer", (Sieger), clamp connections absent from cap cuticle and basidia, (Breitenbach)

Spore deposit:
white or very faintly pinkish (Arora), white (Smith, H.V.), white, sometimes pale pink, (Sieger)

Notes:
It has been reported specifically for BC (Redhead(5)). There are collections from BC and CA at the University of British Columbia, WA, ON, NY, and VA at the University of Washington, and OR at Oregon State University.

EDIBILITY

good but not recommended because sometimes toxic, (Arora), some people eventually become sensitive, exhibiting flu-like symptoms, the gray form being more frequently troublesome than the white, (Sieger)

Synonyms and Alternate Names:
Lepiota leucothites (Vittad.) P.D. Orton