Russula aeruginea

Russula aeruginea Fr., grows with Birch.

Russula aeruginea, also known as the Grass-green Russula, is an inedible russula mushroom, found only under birch, mostly in pine forests; not rare.

More reddish-capped forms could be confused with the sickener (Russula emetica), although the latter always has a white stipe and gills; greener-capped species may resemble the also edible Russula aeruginea.