Coprinus quadrifidus Pk. Cap 2-7cm across at base, 4-7cm high, egg-shaped expanding to bell-shaped; whitish at first from veil remnants, then becoming dingy buff to gray or grayish brown; felty at first, breaking up into loose cottony-flaky patches or warts. Gills free, crowded, broad; white becoming purplish, then blackish or inky. Stem 40-120 x 5-l0mm, hollow; white with brownish rhizomorphs connected to the base; felty, scaly; white partial veil leaving evanescent ring. Taste unpleasant. Spores ellipsoid, smooth, with pore at tip, 7.5-10 x 4-5µ. Deposit blackish. Habitat growing in large clusters on hardwoods, especially elm and ash. Found in northeastern North America west to the Great Lakes. Season June-August. Edibility suspect-may cause stomach upset in some people.