Ceratiomyxa fruticulosa

Scientific name:  Ceratiomyxa fruticulosa (O. F. Mull.)
T. Mac.
Derivation of name: Fruct- means "fruit" and osa means
"fullness" or "abundance."  
Synonyms: Byssus fruticulosa O. F. Mull.  
Common name(s):  Coral slime.
Phylum:   Myxomycota
Order:   Protosteliales
Family:   Ceratiomyxaceae
Occurrence on wood substrate:  Clustered on dead wood;
June through October. 
Dimensions:  Individual fruit bodies are 0.5-1 mm wide and
1-10 mm high.  Great numbers can occur on a log or piece
of wood covering many centimeters or even a meter or more
of woody surface. 
Description:  The tiny, erect, branched or simple structures
of this organism look like small icicles or like tiny pieces of
erect coral. They are whitish and translucent with a fuzzy
appearance because they produce their spores on their
outside surfaces.       
Edibility:  Not edible.  
Comments:  Ceratiomyxa fruticulosa is a slime mold.
While not fungi, slime molds often form spore-bearing
structures that resemble those of the true fungi. Although
many slime mold species fruit on wood they do not form a
penetrating and absorptive mass of hyphae in the wood
substrate. Rather, slime molds form structures called
plasmodia which are naked (i.e., without cell walls) masses of
protoplasm which can move and engulf particles of food in an
amoeboid manner. Slime mold plasmodia creep about over
the surfaces of materials, engulfing bacteria, spores of fungi
and plants, protozoa, and particles of nonliving organic
matter. At some point, plasmodia convert into spore-bearing
structures. In Ceratiomyxa fruticulosa, the plasmodium
converts into a clustered mass of stalks bearing spores on
their surfaces. There is evidence that the spores are actually
one-celled sporangia. 

More information at Wikipedia.org:


Figure 1.  The white horizontal "stripes" on this log are
clusters of Ceratiomyxa fruticulosa. 
Photo © Gary Emberger.

Figure 2.  Up close, this is what one of the white areas in
Figure 1 looks like. Photo © Gary Emberger.

Figure 3. Ceratiomyxa fruticulosa can cover large areas of
rotten wood. It is one of the most common slime molds and
it is worldwide in distribution. Photo © Gary Emberger.

Figure 4. With greater magnification, the translucent nature of
the columns can be seen and also the white, fuzzy outside
surfaces where the spores (or one-celled sporangia) are
formed. Photo © Gary Emberger.