Russula acrifolia (Acrid-gilled Brittlegill)
Russula acrifolia

Deciduous and coniferous forests, parks. Summer, autumn.
Fruiting bodies of the colour and size of Russula adusta and Russula nigricans. Cap from the very beginning blackish-brown, dirty yellowish-greyish-brown, with a blackish tinge. Young gills white, later becoming cream, crowded, very bitter in taste, strongly decurrent. Stem white, later the colour of the cap. Flesh thick, firm, turning slightly reddish when broken or cut, then fading to grey, not bitter. Characteristic features: very similar to Russula adusta and Russula nigricans, but mostly widespread in deciduous forests. Grows singly or in small groups, likes humus-rich, loose soil. So far found only in the Bukta forests (Marijampolė district). Edible. Should be classed as protected.