Cap 2-6 cm broad, convex to plano-convex; surface smooth, viscid, yellowish-brown to orange-brown; margin translucent striate; flesh very thin.
Gills adnexed to short-decurrent, close to sub-distant, with two tiers of lamellulae; pale yellowish when young, becoming yellowish-orange to concolorous with the pileus to pale brown in age.
Stipe 2-10 cm long, 2-6 mm thick, smooth and white to buff above the annulus, dull gray-brown and fibrillose below, mostly equal, with a prominent annulus forming a white to rusty spore coated apical ring that is sometimes missing in age.
Spores 8-11 X 5-6.5 µm, elliptical, light brown in water, non-amyloid, ornamented with low warts. Spore print rusty brown.
Scattered to cespitose on well decayed wood.
Deadly poisonous. Contains alpha-amanitins in sufficient quantities to cause death.
Galerina autumnalis and its close relatives Galerina marginata and Galerina venenata have been mistaken in the past with representatives of the genus Psilocybe by those interested in collecting hallucinogenic mushrooms. This has resulted in several poisonings and at least one death.