Coprinus auricomus: Parasola auricoma
Cap 1.5-4.0 cm broad at maturity, at first ellipsoid to obtuse-cylindrical, expanding to nearly plane, the disc sometimes slightly depressed; margin incurved in youth, finely striate, becoming decurved to plane; surface of disc glabrous, lubricous when moist, with expansion the remaining cap plicate-ribbed and minutely hairy (use hand lens); disc reddish-brown to dull orange-brown, greyish-buff towards the margin; context thin, <1.0 mm, colored like the cap, unchanging; odor and taste not distinctive.
Gills adnexed to barely free, densely packed in youth, close at maturity, edges fimbriate, cream-buff, then tan-brown, eventually greyish-black from maturing spores, deliquescing inconspicuously from the margin; lamellulae up to 4-seried.
Stipe 4.0-8.0 cm long, 2.0-4.0 mm thick, slender, fragile, hollow at maturity, equal or slightly swollen at the base; surface whitish, glabrous, at times lustrous, fibrillose to tomentose at the base; partial veil absent.
Spores 11.0 14.0 x 6.5-7.5 µm, elliptical to ovate in face-view, barely inequilateral in side-view, thick-walled, smooth, with a conspicuous apical pore; spores greyish-black in deposit.
Scattered, gregarious, to clustered in soil or grass, usually near rotting wood, e.g. stumps, wood chips etc.; fruiting after moist periods, late summer (watered areas), and after fall rains; common
Like many of the coprinoid fungi, Parasola auricoma is an ephemeral species, the fruiting bodies typically developing and senescing within a day. It is recognized when young by an orange-brown to rusty-brown, bullet-shaped, striate cap. At maturity the cap is nearly plane, striate-plicate, buff to greyish except for a tawny-brown disc. Parasola leiocephala is similar but more delicate and has distinctly free gills, the gills connected to a collar near the stipe apex. Additionally, it lacks the distinctive pileal hairs of Parasola auricoma. Compare also with Coprinellus micaceus, a more robust species which is similarly colored but has glistening cap granules when young.