Arrhenia obscurata

Pileus
Cap 0.8-2.0 cm broad, convex, convex-umbillicate, to infundibuliform; margin decurved to level in age; surface radially appressed-fibrillose, the fibrils dark-brown over a pale-grey background, hygrophanous, fading in age to lighter shades of grey, sometimes with a satiny sheen when dry; context thin, approximately 1 mm thick, pale grey, unchanging; odor and taste not distinctive.

Lamellae
Gills subdistant, decurrent, medium-grey, up to 2 mm broad, the edges blackish with age; lamellulae in two to three series.

Stipe
Stipe 1.0-1.5 cm long, 1-3 mm thick, hollow, straight to bent, more or less equal; surface glabrous, pale-grey at apex, becoming greyish-brown towards the base, surrounded by grey tomentum; partial veil absent.

Spores
Spores 6.5-9.0 x 3.5-5.0 µm, elliptical-oblong in face-view, elliptical to tear-shaped in profile, smooth, thin-walled, hilar appendage not conspicuous, inamyloid; spore deposit not seen.

Habitat
Solitary or in small groups on bare soil, occasionally in moss in montane regions; fruiting in the spring; occasional to common in its preferred habitat.

Edibility
Unknown; too small to have culinary value.

Comments
This small, omphaloid mushroom, also known as Clitocybe atrobunnea, is easily overlooked, its drab color closely matching the soils on which it often fruits, a feature reflected in the species epithet. Arrhenia obscurata is recognized by a dark-brown, appressed-fibrillose, often infundibuliform cap, and strongly decurrent gills. In California it is most likely to be confused with the similarly colored Arrhenia epichysium. The latter, however, occurs only on decayed wood