Russula olivacea

Russula olivacea is an edible and non-poisonous Russula mushroom found mostly in groups from June in deciduous and coniferous forests, mainly under spruce and beech; not rare.

Description
The cap is convex when young, soon flat, yellowish-olive when young which develops into rusty brown; it ranges from 10-30 cm in diameter. The gills are cream, deep ochre when old and rather crowded and brittle. The spores are yellow. The stem is strong and evenly thick, often pale pink; it ranges from 7-18 cm long and 2-6 cm wide. The flesh is firm, white, with a pleasant or innocuous scent, and has a mild or nutty taste. Some say it is edible and other say it is toxic, perhaps causing gastrointestinal upset.

Similar species
Russula viscida is in size and habitat very similar; the surface of its cap is bright purple to blood red and shiny. The base turns leather yellow when old. Its flesh is quite pungent.