Habitat: Alpine at high elevations; arctic near sea-level.
Substrate: Soil near minute mosses or the white worm lichen.
Conservation Status: Not of concern
Cap very tiny, 3– 6(15) mm across; erect, spoon-shaped, thin-fleshed, pale brown to graybrown; somewhat translucent, often with a lobed margin that is curled over. Gills reduced to a few shallow, widely spaced ridges that branch toward the margin; same color as cap or a bit lighter. Stalk 2– 4 mm long × 1– 2 mm wide, attached to one side of cap; smooth or minutely velvety; pale brown to gray-brown. Spore print white.
Sources: Cripps, Cathy L., Vera S. Evenson, and Michael Kuo. Rocky Mountain Mushrooms by Habitat. Chicago, University of Illinois Press, 2016.
PNW Herbaria: Specimen records of Arrhenia auriscalpium in the Consortium of Pacific Northwest Herbaria database
CalPhotos: Arrhenia auriscalpium photos