Camarops petersii

Scientific name: Camarops petersii (Berk. & M.A. Curtis)
Nannf.
Derivation of name:  
Synonyms: Bolinia petersii (Berk. & M.A. Curtis) Lloyd;
Hypoxylon petersii Berk. & M.A. Curtis   
Common name(s):  
Phylum:   Ascomycota
Order:   Boliniales
Family:   Boliniaceae
Occurrence on wood substrate: Saprobic; solitary or
grouped on decaying (typically decorticated) hardwood logs
(e.g., oak, elm); summer and fall.       
Dimensions:  Cushion-shaped fruit bodies are 2-9 cm wide,
sub-circular to oval to irregular in shape and up to 2 cm high.  
Description: A grayish-brown to yellowish-brown peridium
initially encloses the "flesh" (i.e., stroma) of this ascomycete.
The peridium ruptures to reveal the black, glistening, pimple-
dotted surface of the stroma. The peridium eventually ends
up as a ragged-edged ring of tissue around the periphery of
the stroma. Many perithecia are embedded at various
depths within the stromatal tissue and the ostioles of their
long necks terminate at the pimple-dots on the surface. Dark
ascospores exude from the ostioles (along with an exudate)
to form a wet, shiny film on the surface of the stroma.        
Edibility: Unknown. 
Comments: This species is apparently much more common
than its absence in most field guides would indicate. Its
conspicuous size and shiny, tar-like appearance on logs is
quite eye-catching.

More information at MushroomExpert.com:    

Figure 1. Camarops petersii on a barkless (decorticated)
log. Photo © Steve Nelsen.


Figure 2. Cluster of Camarops petersii on a decorticated
hardwood log. Photo © Dianna Smith.


Figure 3. Same cluster as Figure 2 but photographed three
months later in November. Photo © Dianna Smith.

Figure 4. The ruptured peridium reveals the shiny black
stroma beneath.

Figure 5. Close-up of a portion of Figure 4 showing the torn
peridium and the black, pimple-dot surface of the stroma.

Figure 6. Longitudinal section of a young specimen of
Camarops petersii. The stroma is brownish and many
perithecia form at various depths within it.


Figure 7. Close-up of a portion of Figure 6. The shiny
perithecial cavities are not yet filled with dark ascospores.
Note the long necks of the perithecia which connect to the
stromal surface.

Figure 8. Longitudinal section of an older specimen showing
the perithecia filled with dark ascospores and liquid.

Figure 9. The long dimension of this exceptionally large
specimen of Camarops petersii is 8.5 cm.

Figure 10. The underside of the specimen in Figure 9.
Some of the wood substrate is attached to the specimen.