Jack-O-Lantern Mushroom (Omphalotus olivascens). This mushroom is found west of the Rockies, clustered at the base of hardwood stumps or from buried roots, most common with oaks and eucalyptus. Sometimes it is called a False Chanterelle because of its yellowish color and decurrent gills. It can, however, be distinguished from the true chanterelle, Cantharellus cibarius, by a combination of characters: C. cibarius has ridges rather than true gills, never develops the olive tones of O. olivascens, and grows in oak duff, not on rotting wood. The fruiting bodies of O olivascens are luminescent when fresh.