Summary:
Section Basipedes (Smith), Section Longisetae (Maas Geesteranus) (both as Mycena longiseta). The distinctive feature is the hairs on cap and stem surfaces that are visible with a hand lens. Other features include a dark bluish gray or brownish gray, striate cap that fades, adnexed gills that are grayish or pallid, a delicate gray to whitish stem with small rounded bulb at base, growth on fallen leaves, needles, and cones, and microscopic characters. This species has gone under the name Mycena longiseta Hoehn., Sber. Akad. Wiss. Wien, Math.-naturw. Kl., Abt. 1 118: 282 [8 repr.] 1909. According to A. Aronsen, http://home.online.no/~araronse/Mycenakey/longiseta.htm, accessed June 18, 2012, "Mycena aciculata represents the common, widely distributed, temperate Northern Hemisphere species misidentified in the literature as M. longiseta. M. longiseta is a species restricted to southeast Asia. A commentary on the confusion around the species concept of M. longiseta was published by Desjardin & Horak (2002). M. aciculata differs from M. longiseta primarily in having inamyloid spores, distinctive cheilocystidia, more strongly gelatinized pileipellis tissue, shorter pileosetae, thick-walled caulocystidia and basal disc cystidia, and in lacking pileus marginal cystidia (Desjardin et al. 2002)." (Latin names in italics). The description here is derived from Smith(1) for Mycena longiseta except where noted.

Cap:
0.1-0.5cm across, conic, flaring when old, sometimes becoming convex; "dark bluish gray or brownish gray, becoming sordid pallid gray to whitish"; surface at first appearing downy under a hand lens from setae [small hairs], becoming bald as setae become appressed, translucent-striate but soon becoming sulcate [grooved]

Flesh:
delicate, fragile

Gills:
narrowly attached to stem or nearly free, subdistant, narrow; grayish or pallid, edges colored as faces

Stem:
1-3cm, long and thread-like, equal, readily separable from cap, "very soft and delicate, with a small rounded bulb at the base"; gray but turning whitish when old; covered with setae or nearly bald, base covered with setae, (Smith), 1-3cm x 0.1-0.3cm (Maas Geesteranus)

Taste:
not distinctive

Microscopic spores:
spores 6-8 x 3-4 microns, elliptic, inamyloid; basidia 2-spored or 4-spored; pleurocystidia not differentiated, cheilocystidia abundant, 25-40 x 7-15 microns, clavate to fusoid-ventricose, top drawn out to a needle-like projection or studded with several needle-like projections, some with the enlarged middle part more or less echinulate [finely spiny] in addition; "gill trama of vesiculose cells, vinaceous brown in iodine"; cap trama "composed of a thin gelatinous pellicle (often quite thick when revived in KOH) and a tramal body of vesiculose cells, the latter vinaceous brown in iodine", numerous long, pointed, colorless, thick-walled setae 150-200 x 8-14 microns arising from the pellicle; stem and bulb covered with flexuous [wavy], thick-walled setae up to 300 microns long, (Smith), spores 7.9-9.2 x 3.6-4.0 microns, pip-shaped, smooth, inamyloid, (Maas Geesteranus)

Spore deposit:
[presumably white]

Notes:
Distribution is at least WA, ON, CA, MI, NC, NY, TN, (Smith), BC (Gamiet(1)), and Europe (Maas Geesteranus); there are collections from BC at UBC and Pacific Forestry Center.

EDIBILITY

Synonyms and Alternate Names:
Mycena codoniceps var. aciculata A.H. Sm.