=Agaricus ostreatus= =Pileus:= Four to six inches in diameter; smooth. Color, dull, light yellowish, sometimes pale ochre or grayish. =Gills:= Dingy white; of various lengths, extending down the stem. =Stem:= Short or obsolete; on the side of pileus. =Spores:= White. =Taste:= Agreeable; suggesting the flavor of the cooked oyster; texture tough in older specimens. =Odor:= Pleasant. =Habitat:= On old tree trunks and fallen logs, occasionally in dense masses.