Rhodocollybia butyracea (Bull.: Fr.) Lennox
Mycotaxon 9: 219. 1979.

Common Name: none

Synonym: Collybia butyracea (Bull.: Fr.) Quélet

• Pileus

  Cap 2.5-6.5 cm broad, convex, becoming broadly convex to nearly plane with a low umbo; margin incurved when young, sometimes upturned at maturity; surface smooth, lubricous, reddish-brown, tawny brown to greyish-brown, darkest at the disk, lighter in age; flesh white, thin, soft, unchanging; odor, fungal; taste mild.

• Lamellae

  Gills close, adnexed to nearly free, moderately broad, white, soon pallid, edges irregular, sometimes finely scalloped.

• Stipe

  Stipe 2.5-5.5 cm tall, 0.5-1.0 thick, tapering to an enlarged base; surface smooth when young, faintly longitudinally striate in age, concolorous with the cap but paler; cartilaginous, stuffed, hollow at maturity, often with white to pallid, cottony mycelium at the base.

• Spores

  Spores 6-7.5 x 3.5-4.0 microns, smooth, elliptical, inequalateral; spore print cream-buff.

• Habitat

  Scattered to gregarious or in rings under conifers, occasionally with hardwoods; fruiting from late fall to mid-winter.

• Edibility

  Edible, but unsubstantial. There is little local experience with this mushroom.

• Comments

  Rhodocollybia butyracea is characterized by a smooth, pale, reddish-brown to greyish-brown lubricous cap, nearly free gills with irregular edges, and a cartilaginous usually longitudinally striate stipe. Gymnopus dryophilus is similar but lacks the lubricous cap and has smooth gill edges.

• Other Descriptions and Photos
  • Nathan Wilson: Rhodocollybia butyracea (CP)
  • A revision of Collybia s.l. in the northeastern United States and adjacent Canada: Rhodocollybia butyracea (D & CP)
  • A revision of Collybia s.l. in the northeastern United States and adjacent Canada: Rhodocollybia butyracea f. asema (D & CP)
  • Na Grzyby: Collybia butyracea (D & CP)
  • Pilze, Pilze, Pilze: Collybia butyracea (CP)
  • National Botanic Garden of Belgium: Collybia butyracea (CP)
  • Arora (1986): p. 216 (D), p. 217 (P) [as Collybia butyracea]
  • Breitenbach & Kränzlin (vol. 3): sp. 168 (D, I, & CP) [as Collybia butyracea]
  • Halling: p. 20 (D), fig 1-3 (I), fig 98 (P) [as Collybia butyracea]
  • Jordan: p. 151 (D & CP) [as Collybia butyracea]
  • Miller: sp 141 (D) [as Collybia butyracea]
  • Phillips: p. 60 (D), p. 61 (CP) [as Collybia butyracea]
  • Smith & Weber: sp. 116 (D & CP) [as Collybia butyracea]

  (D=Description; I=Illustration; P=Photo; CP=Color Photo)