Macroscopic features

  Closed pileus ellipsoid or cylindrical ellipsoid, up to 13 mm high and 3-8 mm wide, completely covered with creamy-white, later pale greyish-ochre, powdery veil (according to the description of Watling (l.c.) the pileus is covered throughout with pale grey scurfy sheath-like veil with a faint flush of ochraceous; finally the pileus is evenly sepia with remnants of the veil in irregular patches flushed with ochraceous); veil at margin, particularly in early stages somewhat more hairy-floccose; expanded pileus 10-25 mm wide, first conical or campanulate, later applanate with reflexed margin. Lamellae free, white at first then grey (violaceous grey according to Watling) then black with pale edge. Stipe up to 50 x 1-2 mm, attenuate upwards, white to greyish, with small velar flocks, at base somewhat swollen, white hairy-flocculose. Smell absent. Spore print violaceous black.

Microscopic features

  Spores [20,1,1] 6.0-7.7 x 4.2-5.0 x 4.1-4.5 µm, Q = 1.35-1.70, av. Q = 1.50; av. L = 7.0, av. B = 4.7 µm, cylindrical-ellipsoid in frontal view, ellipsoid in side-view, red-brown, with central, truncate germ pore, difficult to see. Basidia 10-22 x 6-8 µm, 4-spored, surrounded by 3-5 pseudoparaphyses. Pleurocystidia 30-55 x 15-35 µm, ellipsoid, utriform, vesiculose or subcylindric. Cheilocystidia 20-50 x 15-35 µm, ellipsoid or (sub)globose. Veil made up of (sub)globose elements, 25-60 µm in diam., mixed with fusiform or elongate, 2-15 µm wide elements. Clamp-connections present.

Habitat & distribution

  Solitary or a few together. On dung of sheep, cow and horse. Very rare in the Netherlands (One found).

Remarks

  Coprinus utrifer is microscopically easy to identify by its small subcylindrical spores. Some measurements in literature appear to be slightly different: spores (Watling: 7.5-8.5[-9.0] x 4.5-5.5 µm; Josserand: 7.8-8.8 x 4.6-5.3[-5.5] µm); pleurocystidia (Watling: 40-100 x 17-23 µm; Josserand: 60-100 x 20-30 µm), cheilocystidia (Watling: 25-40 x 25-35 µm; Josserand (15-)25-40 x 10-20 µm), but we think the Estonian collection studied fits well in the concept of Coprinus utrifer.
  The species is included here in Sect. Nivei because of the very similar veil, that is made up of (sub)globose and elongate elements. The relatively strongly diverculate elements also resembles the veil found in other groups of Coprinus which is the reason that C. utrifer is placed in different sections by various authors. Kühner & Romagnesi (1953) place it in sect. Impexi, Moser (1983) in sect. Coprinus and Citerin (1992) in sect. Picaceus (see also the paragraph on infrageneric classification).