Summary:
The presence of this species in the Pacific Northwest requires confirmation and its status as an independent species is questioned. Features include 1) a yellowish, viscid, bald cap, 2) adnate to decurrent, close, broad dark gills with white-fringed edges, 3) a white stem with scales below the fleeting narrow ring, 4) a slightly bitter cap skin, 5) growth on dung, 6) a blackish purple spore deposit, and 7) microscopic characters. Hansen, L.(2) gives S. stercoraria (Schum.: Fr.) Quel. as a synonym of Stropharia semiglobata (Batsch: Fr.) Quel. [here regarded as Protostropharia semiglobata], and Breitenbach(4) gives Stropharia semiglobata var. stercoraria (Bull.: Fr.) Lge. (supposed to differ by having capilliform cheilocystidia, a more strongly squamose stem, and an umbonate cap) as a synonym of S. semiglobata (Batsch: Fr.) Quel., as well as implying that S. stercoraria sensu Ricken 1951 (distinguished by growing directly on manure and having lanceolate pleurocystidia) is probably a synonym. Moser(1) differentiates var. stercoraria of S. semiglobata from var. semiglobata by a somewhat umbonate cap, a stem that is more heavily scaly, and hair-like cheilocystidia. Arora(1) differentiates S. stercoraria from S. semiglobata by cap that is usually flat at maturity, a stem that is non-viscid or slightly viscid, and larger spores. The description is derived from Kauffman(1).

Cap:
2-6cm across, convex-hemispheric then broadly convex or somewhat expanded; yellow, buff, or whitish when dry, often stained by spores; viscid from separable gelatinous pellicle; bald

Flesh:
soft, thin on margin; white or tinged yellow

Gills:
adnate becoming somewhat decurrent, close, very broad; umber-fuscous to purplish olivaceous or blackish, edges white; edges fringed

Stem:
6-18cm x 0.2-0.6cm, elongated cylindric, base thicker, stuffed then hollow; yellowish white; covered below ring with floccose scales

Veil:
fleeting narrow membranous ring

Taste:
of pellicle slightly bitter

Microscopic spores:
spores 15-21 x 8-12 microns, elongated elliptic, smooth, violet-purple under microscope; pleurocystidia and cheilocystidia 50-70 x 12-18 microns, lanceolate

Spore deposit:
blackish-purple

Notes:
Stropharia stercoraria Fr. was reported from OR (Kauffman(5)). There is a 1935 collection of Stropharia stercoraria (Schumach.) Quel. from WA at the University of Washington. Stropharia stercoraria was reported also from BC by Davidson 1930 and Lowe 1969, but confirmation would be needed, and Murrill reported it from CA.

EDIBILITY

yes

Synonyms and Alternate Names:
Protostropharia stercoraria (unpublished combination)