Hypomyces chrysospermus Tul. Fruit body a 3-stage mold that grows on boletes. At first it is white and moldy, then it becomes yellow and powdery, and finally it becomes reddish brown and pimpled (this stage is rarely seen). Spores in white stage (asexual), ellipsoid, smooth, 10-30 x 5-12µ; in yellow stage (asexual), globose, warty, thick-walled, 10-25 x 10-25µ; in final stage (sexual), spindle-shaped, transparent, 25-30 x 5-6µ. Habitat singly or in groups on boletes; also reported on paxillus and rhizopogon mushrooms. Common. Found widely distributed in North America. Season June-September. Not edible-possibly poisonous.