Armillaria mellea

Scientific name:  Armillaria mellea (Vahl) P. Kumm.
Derivation of nameMelle- means "honey" or "honey-
colored" referring to the honey color of the cap of this
mushroom.
Synonyms:  Armillariella mellea (Vahl) P. Karst.
Common name(s):  Honey mushroom; Bootlace fungus.
Phylum:   Basidiomycota
Order:   Agaricales
Family:   Physalacriaceae
Occurrence on wood substrate:  Parasitic/saprophytic; in
cespitose clusters at the base of living or dead trees (mostly
deciduous), stumps, or arising from buried wood; June
through fall.  
Dimensions:  Caps are 4-10 cm wide; stalks are 5-15 cm
long and 0.5-2 cm thick.   
Cap:  Sticky to dry yellow-brown cap with erect black
hairs over the center.      
Gills: Attached to subdecurrent, whitish.
Spore print: White.
Stipe:
White above the ring, white to buff to brown below
the ring.
Veil:
Membranous and persistent; whitish, sometimes with
a yellow margin.
Edibility:
Choice with caution.
Comments:
Armillaria mellea and related species are
important forest pathogens. Several species form black
rhizomorphs which spread out and can infect trees at
considerable distances away from the mushroom where they
originated. Underneath the sloughing bark of dead trees
killed by this fungus can be found the black, flattened
rhizomorphs resembling shoestrings or bootlaces. The
hyphae of Armillaria mellea are bioluminescent and wood
colonized by this fungus is referred to as "foxfire." Studies
have revealed that what was once regarded as a species
complex under the name Armillaria mellea is now
understood to be a group of 10 or more closely related
species. Species determination based solely on field
characters is difficult. See the web sites below for keys
and additional information.
  
More information at MushroomExpert.com:   
More information at TomVolkFungi.net:
More information at TomVolkFungi.net:
More information at TomVolkFungi.net:


Figure 1. Cespitose clusters of the honey mushroom at the
base of a tree. Photo © Gary Emberger.


Figure 2. Close up view of one of the clusters in Figure 1.
Note the darker centers of the caps. Photo © Gary Emberger.


Figure 3. "Honeys" have persistent membranous partial
veils. Photo © Pam Kaminski.


Figure 4. The lower stalks are fibrous and brownish
compared to the whitish portion of the stalk above the
ring. Photo © William Roody.


Figure 5. A decaying oak log. Figure 6 reveals the cause
of death. Photo © Gary Emberger.


Figure 6. Examination of the log in Figure 5 reveals the
black, flattened rhizomorphs by which Armillaria mellea
parasitized this tree. Photo © Gary Emberger.


Figure 7. These strange misshapen structures are also an
Armillaria sp. Read the description of Entoloma
abortivum
to understand the connection between
structures such as these, Entoloma abortivum, and
Armillaria
spp. Photo © Gary Emberger.

 

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