species fungus family species genus known europe asia north_america fungus produces fruit bodies usually grow remains mushrooms like species occasionally fruit bodies found rich decayed wood fungus produces small white mushrooms caps diameter supported thin stems originate yellowish brown mushroom difficult distinguish species effort examine usually buried substrate edibility mushroom determined taxonomy phylogeny species described scientific literature var italian mycologist publication reported series cultural studies having single nucleus species determine mating type attempts produce hybrids var species failed sexual indicated taxa separate species raised taxon specific status calling species called publication genus folded considered species variety publication molecular analysis based dna sequences confirmed related species form group comprise genus specific epithet honors british mycologist description caps young mushrooms roughly spherical soon convex flattened maturity reach cap margin rolled inward young matures cap color white cream gills broadly slightly color similar cap close whitish stem equal width usually straight curves long thick upper region stem surface covered appears white powder thin hairs near base stems originate yellowish brown long ranges shape roughly spherical shaped irregular surface pitted mushroom distinctive odor taste edibility unknown deposit spore color white spores smooth tear shaped hyaline translucent measure basidia spore bearing cells hymenium spored hyaline dimensions bases cystidia edges cheilocystidia faces pleurocystidia gills arrangement hyphae tissue varies regular interwoven cap cuticle type tissue hyphae arranged parallel surface formed hyphae roughly diameter clamp connections present hyphae hyphae yellow pigment walls appear cross section interwoven short hyphae resemble higher plants measure diameter similar species likely confused members similar appearance distinguishing typically requires stem base away moss debris stem embedded field distinguished dark brown somewhat resembles microscope provides definitive way distinguishing hyphae rounded elongated character apparent fresh dried material species produce mushroom grows fruit bodies distinct brown spores produced cap surface noted general similarity appearance north american species known parasitic larger cap spaced gills habitat distribution like members genus grows remains mushrooms species fruit bodies occasionally grow decayed wood rich fruit bodies grow scattered groups field study conducted near brass mill sweden revealed heavy metal contamination little effect appearance mushroom possibly substrate partially fruit bodies lower metal concentration underlying found europe asia japan north_america european distribution extends north species widely distributed north_america reported mexico time fungus partial mixed forest dominated conifers environments netherlands component communities saprobic fungi associated land road edge adjacent wall fence planted common oak supported growth mushroom host
Collybia cookei