Armillaria spp.

Scientific name:  Armillaria gallica Marxm. &
Romagn.; Armillaria gemina Berube & Dessur.;
Armillaria ostoyae (Romagn.) Herink; Armillaria
Berube & Dessur.
Derivation of name:  Gallica means ?; Gemina means ?
Ostoyae means ?; Sinapina means ?
Phylum:   Basidiomycota
Order:   Agaricales
Family:   Physalacriaceae
Occurrence on wood substrate:  Most species are
parasitic, some are saprobic; depending on the species,
they may occur as solitary specimens or in cespitose
clusters, they may appear terrestrial or fruit on visible
wood, and they may be associated with hardwood or
conifer tree species; many form black rhizomorphs
allowing for tree-to-tree spread of the fungus. 
Dimensions:  Consult field guides.
Cap:  Smooth or scaly, depending on the species. Consult
field guides.     
Gills: Attached.
Spore print:White.
Stipe: Consult field guides. In species with a cespitose
growth habit, each stipe base tapers to a point.
Veil: Present (but lacking in A. tabescens).
Edibility: The various species are considered edible
which is not surprising given that they were all (other than
A. tabescens) once considered variants of A. mellea.
Even so, some individuals are intolerant.
Comments: The keys in the websites below include
seven Armillaria species found east of the Rocky
Mountains. A number of them can be identified with
certainty only through microscopic examination.

More information (Armillaria) at
More information (A. ostoyae) at
More information (A. gallica) at
More information (key to species) at TomVolkFungi:

Figure 1. A. gallica. Photo © Gary Emberger.

Figure 2. A. gallica. Photo © John Plischke III.

Figure 3. A. gallica and Entoloma abortivum.
Photo © Gary Emberger.

Figure 4. A. gemina. Photo © John Plischke III.

Figure 5. A. ostoyae. Photo © John Plischke III.

Figure 6. A. ostoyae. Photo © John Plischke III.

Figure 7. A. sinapina. Photo © John Plischke III.


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