Rhodocollybia butyracea

An abundant species typical of conifers as well as broadleaves, with a convex to applanate pileus 3 to 6 cm in diameter, ochraceous brown to reddish brown; adnate lamellae, white to pinkish; hollow reddish-brown stipe enlarged at the base; rancid odor and mild, somewhat farinaceous taste.

Cuticle formed by filamentous hyphae, thin- to slightly thick-walled, arranged more or less parallel to slightly interwoven, 2 to 3.5 µm wide, containing brownish intracellular pigment, slightly separated by gelification, septate and with prominent clamp connections at the septa.

Lamellar edge fertile, lacking differentiated elements from basidia or basidioles (cystidia absent).

Lamellar trama regular or parallel.

Basidia clavate, 25 to 30 µm long, 5 to 7 µm wide, with basal clamp connections and four-spored.

Spores ellipsoidal to amygdaliform, smooth, thin-walled, with a pointed end where the hyaline apiculus is located, 6.5 to 8.5 µm long, 3 to 4 µm wide, generally with a large oil droplet or several droplets inside, and slightly dextrinoid in Melzer's reagent.