Summary:
Features include 1) small size, 2) a thin, pleated, buff to yellow brown cap usually with a darker center, toward the margin becoming grayish as it ages, 3) free gills attached to a collar round the stem and withering when old, 4) stem that is fragile, thin, white to buff, and smooth, 5) a black spore deposit; and 6) growth on the ground. Parasola plicatilis was in Section Hemerobi of Coprinus sensu lato. Parasola plicatilis is the more recently published name based on molecular evidence (Redhead(49)). The description is derived from Arora(1) except where noted.

Cap:
1-3cm across when expanded, 0.5-1.5cm high when young, oval or cylindric to conic when young, broadly convex or flat when old; buff to yellow brown, usually with darker (cinnamon brown or fulvous) center, when old becoming grayish except for center; "deeply grooved (pleated) nearly to center", margin sometimes recurved [upturned] when old

Flesh:
very thin, fragile

Gills:
free but attached to a collar around top of stem, well-spaced, narrow; "soon gray and eventually black, but tending to wither rather than liquefy"

Stem:
3-7.5cm x 0.1-0.3cm, thin, hollow, more or less equal, very fragile; white or buff; smooth

Veil:
none (Breitenbach)

Odor:
none (Miller)

Taste:
mild (Miller)

Microscopic spores:
spores 10-13 x 6.5-10 microns, broadly elliptic, smooth, (Arora), spores 9.6-13.3 x 5.9-8.4 x 8.5-10.3 microns, miter-shaped to lentiform [lens-shaped] in front view, elliptic in side view, smooth, dark red-brown, with eccentric germ pore; basidia 4-spored, 25-40 x 11-16 microns, clavate, without basal clamp; pleurocystidia 70-125 x 20-35 microns, cylindric to ventricose, cheilocystidia 35-60 x 16-25 microns, lageniform to clavate or vesicular; cap cuticle of vesicular cells 25-40 x 14-25 microns, some septa with clamps, (Breitenbach), spores 9.5-13 x 6-8 x 8.5-10.5 microns, lentil-shaped, (Trudell), spores 10-14 x 8-10.5 (face view) x 6.5-8 (side view) microns, (Desjardin)

Spore deposit:
black (Lincoff(2))

Notes:
It has been reported from BC (Roberts, C.(1)) and CA (Arora). There is a collection at Oregon State University from OR, and the University of Washington has collections from WA, AK, and UT. It is widespread in North America. Breitenbach(4) gave the distribution as North America, Europe, Asia, North Africa, and Australia.

EDIBILITY

edible (Lincoff(2))

Synonyms and Alternate Names:
Coprinus plicatilis (Curtis) Fr.