Pileus up to 16 x 12 mm when still closed, ochre to cinnamon at centre (Mu. 10 YR 6-7/6, 2.5 Y 5.5/4, K. & W. 5D5, 4A5), paler towards margin (Mu. 2.5 Y 5/5-7/3), up to 20 mm wide when expanded. Lamellae narrowly adnate to free, white to blackish. Stipe 40-80 x 1-2 mm, whitish, pubescent.
  Spores [80,4,4] 9.7-13.7 x 6.1-8.4 µm, av. L= 10.9-12.2, av. B= 6.5-7.4 µm, Q= 1.40-2.10, av. Q= 1.55-1.80, ellipsoid to ovoid; germ pore eccentric, c. 1.8 µm wide. Basidia 15-28 x 6-8 µm, 2-spored. Pseudoparaphyses (3-) 4-5 (-6) per basidium. Cheilocystidia 20-55 x 15-32 µm, vesiculose. Pleurocystidia absent. Pileocystidia 60-120 x 10-22 µm, lageniform with tapering neck, 5-10 µm wide at apex. Sclerocystidia absent. Clamp-connections absent.

Habitat

  Fasciculate on dung, mixtures of straw and dung and also on decaying straw. Common.

Remarks

  Coprinus bisporus is easily recognizable by its two-spored basidia, and its globose to ellipsoid cheilocystidia, by the absence of sclerocystidia and clamp-connections and by its preference for dung or straw dung-mixtures. Only C. bisporiger is close, but that species grows on sticks and among leaves and perhaps has also some morphological differences (see the discussion under that species).