Summary:
Features of Coprinellus impatiens include a small leather-colored pleated cap that dries whitish, gills that deliquesce slowly, a whitish stem, growth in foliage, black spore deposit, broadly oval spores, and other microscopic characters including cheilocystidia and a cellular cap cuticle with pileocystidia. Coprinellus impatiens was in Section Setulosi (with pileocystidia on cap best seen just before opening) along with Coprinellus congregatus, Coprinellus disseminatus, Coprinellus ephemerus, and Coprinellus hiascens according to Moser. There are probably others in this section which has not been fully studied in the Pacific Northwest. The description is derived from Smith(15) except where otherwise indicated.

Gills:
ascending adnate but readily seceding, close to nearly subdistant; light yellowish at first, becoming blackish brown; edges fimbriate [fringed], (Smith), deliquescing slowly (Moser according to that part of key)

Stem:
2-4cm long and about 0.1cm wide, equal or widening very slightly downward, hollow, fragile to moderately pliant; pallid sordid yellowish to grayish, becoming dull whitish when old; "surface very slightly pruinose and appearing dull", (Smith), 5-10cm x 0.1-0.4cm, whitish and downy, (Moser)

Odor:
not distinctive

Taste:
not distinctive

Microscopic spores:
spores 9-11 x 6-7 microns, oval to obscurely angular, smooth, distinct apical pore; basidia 4-spored, trimorphic, the longest 30 x 7-8 microns, the shortest 20 x 8 microns; paraphyses coprinoid, 18-20 x 10-15 microns, inflated, colorless, pleurocystidia none, cheilocystidia abundant, 43-68 x 10-15 microns, fusoid-ventricose, colorless, thin-walled, sessile, apices acute; pileocystidia scattered, 40-80 x 9-15 microns, fusoid-ventricose, colorless above ventricose part, "below with the wall thickened and pale tawny in some", colorless in others; clamp connections not found; caulocystidia abundant, similar to pileocystidia except that their walls are thin and colorless throughout, (Smith), spores 8.5-11 x 5-6 microns, broadly egg-shaped, apiculus small; cheilocystidia usually more or less bottle-shaped [by that part of key], pileocystidia on average over 70 microns (by that part of key) and under 90 microns, (Moser)

Spore deposit:
black

Notes:
Coprinellus impatiens has been found at least in ID and OR, (Smith(15)). There are two O. Ceska collections from BC at the University of British Columbia. It is also found in Europe.

EDIBILITY

edible but of no value (Smith)

Synonyms and Alternate Names:
Coprinus impatiens Quel.