 The edible Coprinellus bisporus is nearly identical but lacks the yellowish cap granules and only has two spores per basidium . The scaly inky cap ( Coprinus variegatus = Coprinus quadrifidus ) has a grayish @-@ brown cap with dull white to brownish scales ; its odor is disagreeable . The trooping crumble cap ( Coprinellus disseminatus , edible ) has smaller , yellow @-@ brown to grey @-@ brown caps and white gills that turn black but do not dissolve away ; it always grows in large clusters on rotting wood ( sometimes buried wood ) . Coprinus atramentarius is a larger , gray species that grows in dense clusters on stumps or on the ground from buried wood , lacks glistening particles on the cap , and the cap and gills dissolve at maturity . Coprinellus radians develops singly or in clumps from a tufted mat of coarse yellow @-@ orange mycelium on the wood . Coprinellus truncorum is also covered with glistening granules and is said to be almost indistinguishable from C. micaceus in the field ; microscopy is needed to tell the difference , as C. truncorum has ellipsoid spores with a rounded germ pore , compared to the shield @-@ shaped ( <unk> ) spores with truncated germ pores of C. micaceus . One study suggests that compared to C. truncorum , C. micaceus is browner in the center of the cap ( rather than grayish ) and has a greater tendency to grow in clusters ; more molecular evidence is required to determine if the two taxa are genetically identical . 
