Cap 1.5-3.0 cm broad, obtuse-conic to convex, eventually plano-convex; margin incurved, then decurved, translucent striate, at maturity inconspicuously striate-sulcate; surface glabrous, lubricous when moist, dull yellowish-olive, olive-brown, to tan-brown; context thin, up to 2.0 mm at disc; whitish to pale yellow; odor and taste slightly farinaceous.
Gill ascending-adnate, close, pale-yellow to pale-grey, becoming cream-buff; edges and faces minutely fringed (use hand lens), not marginate; lamellulae 2-3 seried.
Stipe 2.5-9.0 cm long, 2.0-3.0 mm thick, more or less equal, round, cartilaginous, at first stuffed, then hollow; surface viscid when moist, pruinose, becoming glabrous except at the apex, upper portion pallid, buff, to pale-yellow, shading to mahogany-brown below, context not bleeding a colored juice; whitish hairs at the base; partial veil absent.
Spores 8.5-11.5 x 5.0-6.0 µm, elliptical in face-view, in profile slightly flattened on one side, smooth, thin-walled, hilar appendage inconspicuous; amyloid; spore print whitish.
Solitary to gregarious on woody debris under montane conifers; fruiting in the spring near melting snow; common.
Unknown; too small to have culinary value.
This snowbank Mycena is easily recognized by the contrasting colors of cap and stipe. Young, fresh caps are typically olivaceous and viscid, while the stipe is pale-yellow at the apex and reddish-brown at the base. Older caps fade to a nondescript brown, but the stipe usually retains much of its original color. Also found near melting snow and sometimes confused with Mycena nivicola is Strobiluris albipilatus. The cap of this small, lignicolous species is moist, not viscid, and despite the species name, is not white, but usually some shade of brown. Additionally, the stipe color is straw-yellow to tan-brown.
In the past we have refered to this species as Mycena griseoviridus. Mycena nivicola from the Sierra Nevada differs in several respects from Smith's original description of Mycena griseoviridus, which was based on material collected under oak in the fall in Michigan. These differences, along with DNA evidence, makes this taxa worthy of species recognition. The differences include a dissimilar habitat and fruiting season, a glabrous, not pruinose cap, lamellae lacking olivaceous tints, and a faint, rather than strong farinacous odor and taste.