Cap: 14-16 mm wide, convex then flattened with a central domed area, strongly hygrophanous, translucently striate from the centre, smooth, dark grey brown to olivaceous brown. Flesh: very thin without distinctive smell. Gills: adnexed (rounded towards stem), very broad (up to 4 mm), moderately distant, grey brown; edge lighter in colour, flat. Stem: 20 x 1.5 mm, cylindrical, entirely covered in thin pale striations, yellowish brown, blackening from the base. Spores: 7-10 x 4.5-6.5 μm, Q = 1.3-1.9,thick walled, ellipsoidal to broadly ellipsoidal, flattened in side view or rather bean-shaped, weakly amygdaloid, no apparent pore. Basidia: 25-35 X 6-8 μm, four spored. Cheilocystidia: 40-55 x 5-8 (-10) μm, cylindrical to narrowly lageniform, strongly curved part slightly constricted, barely capitate. Pileipellis: a cutis with weakly inflated hyphae, end elements are inflated, clavate to pyriform. Pileocystida: 35-55 x 6-10 μm, scattered cylindrical bent to narrow lageniform. Caulocystida: numerous, very variable, forked, similar in shape to the other cystidia with strongly curved isolated terminal elements. Pileipellis and stiptipellis weakly to very strongly encrusted with pigment. Clamps common.