Summary:
An important feature when present is 1) the yellow color at the top of the stem, but observe young specimens. Other features include 2) small size, 3) an umbilicate or papillate striate cap that is fuscous on the disc and drab toward the whitish margin, 4) pallid to grayish gills, 5) a cartilaginous stem that is pallid or yellowish to greenish yellow at the top and pallid grayish in the lower part, 6) growth on bark and sticks in spring to fall, typically in wet or muddy places, and often in large numbers, 7) a white spore deposit, and 8) microscopic characters. The description is derived from Smith(1) except where otherwise specified. Smith(1) says it is nearly always found with Mycena acicula.

Gills:
adnate and horizontal or arcuate and decurrent, subdistant (9-12 reaching stem), 2 tiers of subgills, gills narrow to moderately broad, interveined; pallid to grayish, edges pallid; edges even

Stem:
1-3(6)cm long and up to 0.1cm wide, equal, flexuous [wavy], cartilaginous and firm, tubular; pallid or yellowish to greenish yellow at top, pallid grayish in lower part, or when old yellowish over all, [this coloring describes forma camptophylla according to Maas Geesteranus, with forma speirea having stem top watery whitish or suffused with brown, and there is also a whitish form]; base usually crooked and conspicuously white-strigose [white-hairy]

Veil:
[none]

Odor:
not distinctive or slightly farinaceous

Taste:
not distinctive or slightly farinaceous

Microscopic spores:
spores 7.5-9(10) x 4-5.5 microns, suboval [more or less oval], often with a prominent curved apiculus, [smooth according to Maas Geesteranus], inamyloid; basidia 2-spored or 4-spored; pleurocystidia not differentiated, cheilocystidia "abundant, resembling sterile basidia when young but becoming elongated" (23)26-38 x 5-8 microns, subcylindric when old and somewhat irregular in outline, colorless; "gill trama of interwoven hyphae, sordid yellowish in iodine"; cap trama "with a thin, often poorly differentiated pellicle, a distinct hypoderm, and the remainder of interwoven filamentous hyphae, yellowish in iodine", (Smith), hyphae of cortical layer of the stem 2.5-3.5 microns wide, without clamp connections, "covered with caulocystidia (either solitary or occurring in dense tufts, and sometimes fairly thick-walled)", 15-100 (or more) x 2.5-5.5 microns, (Maas Geesteranus)

Spore deposit:
white (Breitenbach)

Notes:
It has been found at least in WA and MI, (Smith). It also occurs in Europe, northern Africa, and Japan, (Maas Geesteranus). It has been reported from Australia (Breitenbach). There are collections from BC at the University of British Columbia.

EDIBILITY

Synonyms and Alternate Names:
Mycena speirea (Fr.) Gillet