Megacollybia platyphylla (Persoon: Fries) Kotlaba & Pouzar
Ceská Mykologie 26: 220. 1972.

Common Name: none

Synonym: Tricholomopsis platyphylla (Persoon: Fries) Singer

• Pileus

  Cap 6.0-9.0 (11.0) cm broad, convex, becoming plano-convex to plano-depressed; margin incurved, then decurved, wavy to indented; surface dry, grey-brown, appearing streaked from appressed fibrils over a pallid ground color, the disc sometimes darker and tomentose; context firm, white, unchanging, thin at the margin, up to 1.0 cm thick at the disc; odor and taste mild.

• Lamellae

  Gills adnexed to notched, distant, broad, up to 1.0 cm, cream to pale grey, edges often torn in age; lamellulae up to 4-seried.

• Stipe

  Stipe 7.0-12.0 cm long, 1.0-2.0 cm thick, more or less equal, occasionally enlarged at the base, stuffed to hollow at maturity; surface pruinose at apex, the lower portion streaked with innate pale brown fibrils, white rhizomorphs at base; partial veil absent.

• Spores

  Spores 7.5-9.0 x 5.0-6.0 µm, ovate to elliptical, thin-walled, smooth, hilar appendage apparent, inamyloid; spore print white.

• Habitat

  Solitary, scattered, to occasionally clustered, on or near rotting logs and stumps, both hardwoods and conifers; fruiting spring and fall; uncommon.

• Edibility

  Questionable; some adverse reactions have been reported.

• Comments

  A common mushroom of the eastern United States, Megacollybia platyphylla is rare in California. It is recognized by a a grey-brown streaked cap, unusually broad gills and lignicolous habit. Look-alikes include species of Pluteus, Tricholoma, and larger Mycenas. Pluteus species such as P. atromarginatus and P. petasatus have similarly colored caps, but can be distinguished by free gills, pinkish at maturity; similarly colored Tricholomas differ in lacking a lignicolous habit; larger Mycenas like M. overholtzii and M. galericulata lack deep, notched gills, and have amyloid spores.

• Other Descriptions and Photos
  • Michael Wood: Megacollybia platyphylla (CP)
  • Michael Wood: Megacollybia platyphylla (CP)
  • Na Grzyby: Megacollybia platyphylla (D & CP)
  • Macrofungi of Costa Rica: Megacollybia platyphylla (D & CP)
  • SociΘtΘ Mycologique de Strasbourg: Megacollybia platyphylla (CP)
  • John Walker: Megacollybia platyphylla (CP)
  • University of Tennessee: Megacollybia platyphylla (CP)
  • Arora (1986): p. 146 (D) [Tricholomopsis platyphylla]
  • Breitenbach & Kränzlin (v. 3): sp. 296 (D, I, & CP)
  • Jordan: p. 167 (D & CP)
  • Lincoff: p. 807 (D), pl 265 (CP) [Tricholomopsis platyphylla]
  • Miller: sp. 79 (D & CP) [Tricholomopsis platyphylla]
  • Orr & Orr: p. 256 (D) [Tricholomopsis platyphylla]
  • Phillips: p. 46 (CP), p. 47 (D) [Tricholomopsis platyphylla]

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