Russula illota

Species associated with calcareous soils under Fagus or Picea, with a hemispherical pileus 4 to 15 cm in diameter, ochre with reddish-brown flushes; pale cream spore print; lamellar edges with characteristic abundant blackish spots; cavernous and hollow stipe; unpleasant odor of bitter almonds and acrid, nauseating taste.

Cuticle formed by filamentous hyphae, interwoven, 3 to 5 µm wide, widely spaced by gelification, with abundant terminal elements acting as pileocystidia, cylindrical to subulate, 3 to 6 µm wide, containing brownish granular pigment, septate with simple septa.

Cheilocystidia and pleurocystidia cylindrical to fusiform, mostly with an apical appendage, 50 to 90 µm long, 6 to 10 µm wide, with granular content that darkens with sulphovanillin.

Basidia clavate, 50 to 65 µm long, 10 to 12 µm wide, simple-based and four-spored.

Spores subglobose, with warts up to 1.3 µm high, 7 to 8.5 µm long, 6 to 7.5 µm wide, ornamented with coarse warts that occasionally join to form short ridges.