Entoloma abortivum

Scientific name:  Entoloma abortivum (Berk. & M.A. Curtis)
Donk
Derivation of name:  Abortivum refers to the misshapen
structures often found in association with this species.
Synonyms:   Clitopilus abortivus Berk. & M.A. Curtis
Common name(s):  Aborted Entoloma.
Phylum:   Basidiomycota
Order:   Agaricales
Family:   Entolomataceae
Occurrence on wood substrate:  Saprobic on wood: solitary
to clustered on or near decaying deciduous wood such as
stumps, logs, or buried wood; August through November.  
Dimensions:  Caps are 5-10 cm wide; stalks are 2.5-10 cm
long and 5-15 mm thick.  
Cap: Dry; gray to grayish-brown.       
Gills:  Decurrent; pale gray when young and pinkish at maturity.
Spore print: Salmon-pink.
Stipe: Colored like the cap.
Veil: Absent.
Aborted structures: The presence of misshapen fruitbodies,
described as "aborted," is actually what most people use to
identify this Entoloma species. These aborted structures may be
found with or without the gilled Entoloma abortivum nearby.
The aborted structures are 2.5-5 cm tall and 2.5-10 cm wide;
whitish masses with pinkish marbling within a spongy white flesh.
Edibility: Edible with caution, see below.
Comments: For years, field guides indicated that the aborted
forms of Entoloma developed in response to being parasitized
by Armillaria spp. such as Armillaria mellea. Recent work
indicates that the relationship is the other way around, that is,
Entoloma is the parasite and the aborted structures are
Armillaria spp. Both the aborted Armillaria structures and
Entoloma abortivum are edible but care must be taken not to
eat other members of the Entoloma genus, some of which are
poisonous.

More information at MushroomExpert.com:
More information at TomVolkFungi.net:


Figure 1. Entoloma abortivum and aborted structures.
Photo © William Roody.


Figure 2. Mature pinkish gills and immature white gills of
Entoloma abortivum.

Figure 3. Typical gray-capped Aborted Entoloma. Aborted
Entoloma is no longer a very appropriate common name
because we now better understand the true identity of the
aborted structures. Photo © Larry Grand.

Figure 4. Closeup of aborted Armillaria spp. The aborted
forms are described as whitish, chalky, bumpy, or streaked
with a firm to spongy texture.


Figure 5. Three aborted forms. The inside flesh of these
specimens is shown in Figure 6.

Figure 6. The typical marbled, streaked flesh of aborted
Armillaria structures. These sections are of the aborted forms
shown in Figure 5.


Figure 7. In view from left to right is Armillaria mellea,
aborted Armillaria mellea, and Entoloma abortivum,
the players in our drama of parasitism and mistaken
identity. Photo © John Plischke III.