Macroscopic features

  Closed pileus globose, subglobose to ellipsoid or oval, up to 8 mm high and 4 mm wide, at first white to grey or pale brownish with powdery white veil beneath a cortina-like covering; expanded pileus 5-12 mm, then margin conspicuously split in the shape of a star and centre of pileus pale grey-brown; lamellae free, somewhat distant, white to blackish; stipe 20-50 x 0.5-1.2 mm, hollow, equal or attenuate upwards, when young covered with white velar flocks, at base more dense and forming a volva-like ring zone; smell absent.

Microscopic features

  Spores (8-)9-11.5 x 6-7(-7.5) µm, in side view somewhat cylindrical, oval or ellipsoid in frontal view, with central germ pore, dark red-brown; basidia 4-spored; cheilocystidia 18-45 x 8-13 µm, variable in shape: (sub)globose, ellipsoid, elongate-ellipsoid, utriform or (mostly) lageniform; pleurocystidia up to 60 µm in length, ellipsoid or utriform; pileipellis made up of ventricose, ellipsoid and subglobose elements covered by about 7 µm wide hyphae consisting of oblong-ventricose elements and these passing upwards into thin-walled colourless to slightly yellowish, smooth to granular, up to 45(-55) µm wide, globose velar elements, mixed with elongate elements; clamp-connections present.

Habitat & distribution

  Gregarious. On dying grass ( stems of Festuca). Known only from the type locality.

Remarks

  The description and illustration given here are based on the original description by Enderle & Bender (l.c.)
  The most important differentiating characters of Coprinus pilosotomentosus are the dominantly lageniform cheilocystidia, presence of pleurocystidia and occurrence on grasses. Apart from some dung-inhabiting species, the only species in this subsection with pleurocystidia is Coprinus idae. This species differs in shape of cheilocystidia which are globose to utriform, the smaller, differently shaped spores, and smaller fruitbodies.
  Enderle & Bender (l.c.) do not indicate in which (sub-)section their species should be placed. On account of the structure of the veil, we place it in subsect. Nivei.