Russula firmula

Russula firmula is a species of mushroom found in Europe and parts of Asia that has dark red-purple to red-brown cap. It is one of about 750 species in the genus Russula, which is distributed worldwide. Together with R. rubra, R. rutila and R. veternos, it was placed in the Rubrinae clade in 2017.

Description
Russula firmula has a yellow spore print. Its spores measure about 8.4 by 7 μm and have .8-1.2 μm high spines. Its pileocystidia measure around 72.5 by 10.3 μm. There are incrustations on its pileocystidia which stain bright pink after about 30 minutes in sulphovanillin, in contrast with the rest of the pileocystidia which stain black. The terminal cells at the cap margins are cylindrical, though tapered narrowly at one end. The basidia are around 46 by 12.8 μm.

Ecology
It is ectomycorrhizal with conifers, particularly spruce trees. It has a bitter taste.