Macroscopic features

  Pileus c. 15 x 10 mm when still closed, up to 30 mm when expanded, ellipsoid or ovoid when young, first white, soon greyish. Veil white to grey, breaking up in radial hairy/fibrillose flocks, not in patches. Lamellae, L = 18-42, l = 0-3, rather crowded, free, first white, then grey, finally blackish. Stipe up to 80 x 1-3 mm, whitish, base slightly clavate.

Microscopic features

  Spores [40,2,1] 9.0-11.8 x 7.0-9.1 µm, ovoid, rather truncate, very dark red-brown, with warty ornamentation and central, 1.5-2 µm wide germ pore; Q = 1.15-1.40, av. Q = c. 1.30; av. L = 10.3-10.6, av. B = 7.9-8.1 µm. Basidia 16-34 x 6-8 µm, 2-spored, surrounded by 3-6 pseudoparaphyses. Pleurocystidia 50-80 x 30-40 µm, ellipsoid, utriform or broadly cylindrical. Cheilocystidia 30-70 x 20-35 µm, (sub)globose, ellipsoid, narrowly ovoid, utriform or broadly cylindrical. Elements of veil thin-walled, diverticulate, 2-8 µm wide. Clamp-connections present.

Habitat & distribution

  Solitary or a few together on wood, also found on charcoal. Very rare. Only known from Belgium and the Netherlands, one find each.

Remarks

  Like Coprinus lagopides, this species is characterized by warty, ovoid spores, which are born on 2-spored basidia. Therefore one could think it is only a 2-spored form of that species, but then one would expect the spores to be distinctly larger than in the 4-spored C. phlyctidosporus. For the time being we keep Coprinus rugosobisporus separate.