Asterophora parasitica

Asterophora parasitica, commonly known as the parasitic Asterophora or the Russula parasite, is a species of fungus that grows as a parasite on other mushrooms. The fruit bodies are small, with silky fibers on the surface of grayish caps and thick, widely spaced gills. Mushrooms fruit in clusters on the decaying remains of Lactarius and Russula species, particularly those in the Russula nigricans group. Found primarily in temperate zones of Europe and North America, the fungus is widespread but not common....read more on Wikipedia.