Macroscopic features

  Pileus 27 mm wide, plano-convex, completely white-powdery. Lamellae L = c. 26, l = 1-3, free, first white, then grey to blackish spotted. Stipe 45 x 1.5 mm, with subbulbous base, whitish-hyaline, covered with white velar flocculi. Smell absent.

Microscopic features

  Spores [60,2,2] 5.9-8.3 x 4.8-5.9 x 4.0-4.3 µm, Q = 1.05-1.45, av. Q = 1.25, av. L = 6.7-6.8 µm, av. B = 5.3-5.4 µm, in face view more or less hexagonal but frequently with two rounded lateral nodules at each side because of slightly depressed lateral faces, red-brown, with central germ pore. Basidia 13-32 x 6-8 µm, 4-spored, surrounded by 3-5 pseudoparaphyses. Cheilocystidia 20-35 x 8.5-15.5 µm, mostly utriform; neck 6-9.5 µm wide. Pleurocystidia absent. Veil on pileus consisting of up to 50 µm wide, smooth or somewhat granular globose elements mixed with frequently branching, colourless, thin-walled hyphae with processes. Clamp-connections present.

Habitat & distribution

  Terrestrial on lawn. Very rare.

Remarks

  Coprinus iocularis can be recognized immediately by the characteristic shape of its spores. In face view the spores are more or less hexagonal (because of the two rounded lateral nodules at each side), in side view elliptical.