Megacollybia rodmanii
Scientific name: Megacollybia rodmanii R.H. Petersen,
K.W. Hughes & Lickey
Derivation of name: TBD
Synonyms: Megacollybia platyphylla (Pers.)
Kotl.
& Pouzar; Tricholomopsis platyphylla (Pers.) Singer;
Collybia platyphylla (Pers.) P. Kumm.
Common name(s): Broad gill; Platterful mushroom.
Phylum: Basidiomycota
Order: Agaricales
Family: Marasmiaceae
Occurrence on wood substrate: Saprobic; solitary to
several on and near deciduous logs, stumps, wood debris or
on ground from buried wood; May through October.
Dimensions: Caps 5-12.5 cm wide and stipes 7.5-12.5
cm long and 1-2 cm thick.
Cap: Smooth; brownish-gray caps; radially streaked with
dark fibers.
Gills: Attached; white; broad; edges uneven to ragged,
appearing eroded.
Spore print:White.
Stipe: White, smooth, often with white rhizomorphs
present at the base.
Veil: Absent.
Edibility: Edible.
Comments: There was once thought to be a single,
worldwide species, Megacollybia platyphylla. A
DNA-
based study in 2007 supports the presence of 8-9 species
worldwide with 4 species in North America. Megacollybia
rodmanii is the species occurring in the northeast. There
are two forms, f. rodmanii and f. murina. They are not
distinguished here but information allowing separation of the
two forms is provided at the following websites:
More information at MushroomExpert.com:
More information at MushroomExpert.com
Figure 1. A group of platterful mushrooms arising from a
stump. Photo © William Roody.
Figure 2. This young specimen is oozing water from the
stipe. The gill edges are even. A white rhizomorph is visible
to the left of the stalk base.
Photo © Gary Emberger.
Figure 3.
Megacollybia rodmanii. Photo © John
Plischke III.
Figure 4. Caps sometimes crack or split when drying out.
Photo © Gary Emberger.
Figure 5. Caps of Megacollybia rodmanii are streaked
with dark, radial fibers. Photo © Gary Emberger.
Figure 6.
The gill edges of this mature specimen are quite
ragged. Compare to the gills visible in Figure 2.
Photo © Gary Emberger.