Russula nauseosa

Species associated with conifers, with a convex to applanate pileus with a depressed center, 3 to 7 cm in diameter, color highly variable from ochraceous brown to vinaceous brown; pale yellow spore print; hollow white stipe spotted with brown; indistinct odor and mild taste.

Cuticle formed by cylindrical hyphae 2 to 3.5 µm wide, interwoven, separated by gelification, with abundant large pileocystidia, cylindrical to clavate, 4 to 9 µm wide, containing copious blackish-brown granular matter; all hyphae septate with simple septa.

Cheilocystidia scattered, fusiform, with an apical appendage, 35 to 60 µm long and 7 to 9 µm wide.

Pleurocystidia few, of similar morphology to cheilocystidia, 50 to 70 µm long and 9 to 12 µm wide; both cheilocystidia and pleurocystidia contain blackish-grey granular content inside.

Basidia clavate, 30 to 45 µm long, 9 to 12 µm wide, simple-based and four-spored.

Spores subglobose to ellipsoidal, with warts up to 1 µm high, 7 to 9 µm long, 6 to 8 µm wide, surface covered with numerous isolated warts that occasionally join to form very short, separated ridges.