Stereum ostrea

Scientific name:  Stereum ostrea (Blume & T. Nees) Fr.
Derivation of name: Ster- means "tough, firm, solid."
Ostre- means "oyster" in reference to their shape.
Synonyms: Thelephora ostrea Blume & T. Nees  
Common name(s):  False turkey tail.
Phylum:   Basidiomycota
Order:   Russulales
Family:   Stereaceae
Occurrence on wood substrate: Saprobic; clustered on
decaying logs, stumps, and branches of deciduous trees; June
through December.  
Dimensions: Petal to fan-shaped or semicircular caps are 1-
7 cm wide.  
Sterile upper surface:  Covered with silky hairs; zonate with
orange, gray, reddish-brown, and other colored zones; often
whitish at the margin.
Fertile lower surface: Smooth (small bumps may be
present), buff to cinnamon-buff to reddish-brown.     
Edibility: Inedible.
Comments:  This is our largest and most colorful Stereum
species. It is sometimes confused with turkey tail, a species
of polypore. Use a hand lens to make sure pores are absent.
Recent DNA evidence indicates that the species called
Stereum ostrea does not occur in North America and has
been misapplied to the North American species Stereum
lobatum, S. fasciatum, and S. subtomentosum. Stereum
ostrea, as applied to this page and in some of the picture
captions, is best considered a "placeholder" name at this
time. Some club identifiers employ a "S. ostrea complex"
designation for field identication purposes.

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Figure 1. Stereum ostrea clustered on a log.
Photo © Gary Emberger.

Figure 2. False turkey tail is sometimes confused with
turkey tail, Trametes versicolor, a species with a poroid
fertile surface. A hand lens will confirm the absence of
pores in false turkey tail. Photo © Gary Emberger.

Figure 3. Overlapping clusters of false turkey tail. Sterium
ostrea fruit bodies do not tend to fuse together as much as
some other Stereum species. Photo © Gary Emberger.

Figure 4. The colorful, zonate upper surfaces of Stereum
ostrea. Photo © Gary Emberger.

Figure 5. Some of these false turkey tails are almost fused
in such a way as to form funnels. I have collected some
specimens that are actually in the form of a funnel.
Photo © William Roody.

Figure 6. The specimen on the right in the foreground was
placed upside down in order to show the fertile surface.
Note the white margin. Photo © Gary Emberger.


Figure 7. The smooth, fertile, basidia-bearing lower
surface (left) compared to the sterile silky, zonate upper
surface on the right. Photo © Gary Emberger.