Byssocorticium atrovirens

About

Byssocorticum atrovirens is a species of corticoid fungus in the family Atheliaceae. It is found primarily in eastern North America and Europe, as well as on the West Coast of the United States. The basidiocarp, or fruiting body, is web-like and is initially bright blue before darkening and becoming greener. The mycorrhizas are paler but overall similar in structure and color.

Summary from Wikipedia