Closed pileus ellipsoid, then cylindrical ellipsoid, 12-20 mm high and 6-12 mm wide, completely covered with white, later greyish, powdery veil; veil at margin, particularly in early stages somewhat more hairy-floccose; expanded pileus 20-40 mm wide, at first conical, later expanded, undulated with splitted, reflexed margin. Lamellae, L = 22-36, l = 1-3(-5), free, white at first then grey to black with pale edge. Stipe up to 50-120 x 3-5 mm, attenuate upwards, white to greyish, with white velar flocks, at base somewhat swollen, densely white flocculose. Smell somewhat yeast-like (coll. Bender); of coconut, cinnamon, fruit-drop, holy grass, Anthoxanthum odoratum (coll. Veldre). Spore print black with violet hue.
  Spores [60,3,3] 9.2-12.3 x 7.5-11.3 x 6.2-7.8 µm, Q = 1.05-1.35, av. Q = 1.15-1.20; av. L = 10.6-11.5, av. B = 8.8-9.9 µm, limoniform in frontal view, ellipsoid in side view, dark red-brown, with central to slightly eccentric germ pore. Basidia 15-40 x 9-13 µm, 4-spored, surrounded by 4-6(-7) pseudoparaphyses. Pleurocystidia 75-180 x 25-50 µm, utriform, vesiculose or subcylindric. Cheilocystidia 40-65 x 20-27 µm, utriform, vesiculose, ellipsoid or subcylindric. Veil made up of up to 75 µm wide, (sub)globose elements. Clamp-connections sparse, difficult to find. Probably just pseudoclamps.

Habitat & distribution

  Solitary or a few together. On cow-dung and compost heaps. Rare in the Netherlands.

Remarks

  The macroscopical description of Coprinus pseudoniveus is based upon the collection of Bender. Both this collection, and that of Veldre, had a striking smell according to their collectors, although their descriptions of this smell is rather different. Coprinus species with a striking smell are rare, except for the taxa in subsect. Narcotici. Coprinus pseudoniveus, however, belongs to the C. niveus complex, because of the limoniform spores and structure of the veil. It has distinctly smaller spores and narrower cystidia than C. niveus. Coprinus cothurnatus has smaller, more hexagonal spores, and is usually devoid of pleurocystidia; C. pachyspermus has 2-spored basidia.