Gymnopus dryophilus

Gymnopus dryophilus is a species of mushroom, until recently most frequently known as Collybia dryophila. It belongs to section Levipedes of the genus, being characterized by a smooth stem having no hairs at the base (in contrast to section Vestipedes). The species is commonly found in temperate woodlands of Europe and North America. It is generally saprophytic, but occasionally also attacks living wood. The caps have been considered edible but can cause severe gastrointestinal issues....read more on Wikipedia.