Kees Uljé Coprinus site

Coprinus argenteus P.D. Orton

Coprinus argenteus P.D. Orton, Notes R. bot. Gdn Edinb. 32 (1972) 139.

[Copyright © by Uljé]

Macroscopic features

  Pileus 10 x 4 mm when still closed, up to 15 mm when expanded, ellipsoid conical oblong or ovoid, first white, soon more greyish. Veil white, often somewhat yellow-brown at centre, breaking up in patches. Lamellae free, rather crowded, first white, then greyish, finally blackish. Stipe up to 20 x 1-2 mm, whitish, base clavate, with small, tomentose disk.

Microscopic features

  Spores [40,2,1] 4.5-6.7 x 4.5-6.1 x 4.3-5.8 µm, the shape of a maize-kernel, truncate, medium red-brown, with central, c. 1 µm wide germ pore; Q = 0.95-1.25, av. Q = c. 1.10; av. L = 5.6-5.9, av. B = 5.2-5.4 µm. Basidia 14-26 x 8-9 µm, 4-spored, surrounded by 4-6 pseudoparaphyses. Pleuro- and cheilocystidia not found in type-material (see note). Elements of veil thin-walled, diverticulate, 2-7(-10) µm wide, slightly incrusted. Clamp-connections present.

Habitat & distribution

  Solitary or a few together. In grassland on calcareous soil. Very rare, only known from England.


  Coprinus argenteus can be recognized by the typical shape of the spores in combination with the thin-walled velar elements. The type-material consisted of a fragment of a pileus only, and therefore no cystidia could be studied. In the original description no cystidia were mentioned and Orton stated: 'Cystidia not noted'.

Copyright © by Kees Uljé
Edited for the Web with help from Marek Snowarski Fungi of Poland site