Notes:
Rhodocollybia butyracea (Bull.) Lennox, Tricholomataceae, Agaricales (Коллибия масляная).

Small mushroom yellowish-brown knobbed cap, brownish-white hollow fibrous stalk

Cap: 3-6 cm wide, convex, then wide convex with a knob up to flatten or sunken with a gentle knob and margins curved down; yellowish-brown or brown and knob is darker than margins; surface smooth and glossy and often shining, sometimes with somewhat as white powder above a knob; indistinct radial lined along margin or out of knob.
Gills: attached with notched edge (pinching end), white up to brownish-white or yellowish when old, moderately broad up to broad with short and very short additional gills.
Stalk: 5-10 cm long, 0.8-1.6cm thick, enlarged down when young, hollow, whitish up to brownish-white; indistinct fibrous up to fibrous.
Edibility: no data for this mushroom.
Habitat: rare kind; scattered small groups in pine-tree forest with some birches and aspen.
Season: July – August.