Pileus up to 18 x 9 mm when still closed, up to 30 mm when expanded, subglobose to oblong, densely covered with mealy to hairy floccose veil, mouse-grey or grey-brown. Lamellae free, white to black. Stipe up to 70 x 1.5-3 mm, whitish; base somewhat clavate. Smell strongly >narcotic=.
  Spores 13.7-17.3 x 8.3-10.6 µm, Q = 1.50-1.85, av. Q = 1.65, av. L = 15.1 µm, av. B = 9.1 µm, ellipsoid or ovoid, with conical base and rounded to somewhat truncate apex, dark red-brown; germ pore central, 1.5-1.8 µm wide; episporium strongly developed, wrinkled, up to 2.5 µm wide in places. Basidia 4-spored, surrounded by 3-6 pseudoparaphyses. Pleurocystidia 50-130 x 30-65 µm, utriform, oblong or subcylindric. Cheilocystidia 40-100 x 40-70 µm, (sub)globose, ellipsoid, oblong, utriform or subcylindric. Pileipellis made up hyphoid elements. Elements of veil up to 80(-100) µm wide, made up of globose, warty cells connected with narrow, diverticulate hyphae. Clamp-connections not found.

Habitat & distribution

  Very rare, on dung and on the ground. Known from France, Great Britain and The Netherlands.

Remarks

  Coprinus radicans is related to C. narcoticus but has much larger spores and grows on dung in most cases.