Summary:
Section Fuliginellae (Smith), Section Cinerellae (Maas Geesteranus). Features include 1) small size, 2) a gray, dry to lubricous cap that fades to dingy yellowish or whitish, 3) white gills that become gray, 4) a viscid, bluish black to fuscous stem that becomes gray, and 5) microscopic characters. Note the possibility of confusing the similarly named Mycena clavularis, a European species that grows on bark. The description of M. clavicularis is derived from Smith(1) except where noted.

Cap:
(0.5)1-2cm across, "convex to obtuse when young, rarely obtusely conic", becoming broadly convex or with a low obtuse umbo when old, sometimes becoming depressed on disc; not hygrophanous, dark to light gray, often bluish gray at first, margin pale gray; fading slowly to dingy yellowish or whitish; moist or lubricous but not viscid, pruinose becoming bald and wrinkled to grooved, faintly translucent-striate when moist, (Smith), 1-2cm across, "dry but readily becoming lubricous when moist", (Maas Geesteranus), dark gray to dark brown in the center, (Trudell)

Flesh:
thin, pliant, cartilaginous; grayish or pallid

Gills:
bluntly adnate to slightly arcuate, sometimes with decurrent tooth, subdistant to distant, 15-20 reaching stem, 2-3 tiers of subgills, gills narrow to moderately broad (about 0.2cm); white when young, becoming dingy pale gray, edges pallid; edges even, (Smith), attached to somewhat decurrent; pale grayish or brownish, (Trudell)

Stem:
2-5cm x 0.1-0.15cm, equal, but the base narrowed slightly or enlarged slightly, elastic, cartilaginous; bluish black to fuscous when young and fresh, usually cap-colored or paler when old, becoming slightly tinged with yellowish gray; pruinose in upper part when young, soon bald, viscid, glutinous in wet weather, some mycelium at base, (Smith), "about the same color as the cap", (Trudell)

Odor:
not distinctive

Taste:
not distinctive

Microscopic spores:
spores 7-8.5(9) x 3-4 microns, elliptic, amyloid, [presumably smooth]; basidia 4-spored or rarely 2-spored, 28-33 x 5-6 microns; cheilocystidia and pleurocystidia similar, scattered to numerous, (22)30-38 x 9-12(14) microns, broadly clavate, enlarged part covered with short obtuse projections, colorless; "gill trama pale vinaceous brown in iodine, subhymenium not gelatinous and gill edge not gelatinizing"; cap trama with thin, adnate, nongelatinous pellicle, hypoderm sharply differentiated, its cells 20-40 x 15-25 microns and occupying nearly half the thickness of the cap, the remaining tissue floccose and filamentous, all except the pellicle faintly vinaceous brown in iodine, (Smith), hyphae of cap cuticle 2.5-4.5 microns wide, clamped, embedded in gelatinous matter, covered with simple to branched, cylindric excrescences 0.9-20 x 0.9-1.8 microns, forming very dense masses that tend to dissolve when old, (Maas Geesteranus)

Spore deposit:
white (Phillips)

Notes:
Mycena clavicularis has been found at least in WA, OR, NS, ON, AL, CA, MI, NC, NY, PA, TN, and Europe, (Smith). There are collections from BC at the University of British Columbia.

EDIBILITY