Daldinia concentrica

Scientific name:  Daldinia concentrica (Bolton:Fries) Cesati
& de Notaris
Derivation of name:  Concentrica refers to the concentrically
zoned interior.
Synonyms:  
Common name(s):  Carbon balls; Crampballs; King Alfred's
cakes.
Phylum:   Ascomycota
Order:   Xylariales
Family:   Xylariaceae
Occurrence on wood substrate:  Saprobic; clustered on dead
deciduous wood; year-round.  
Dimensions: Fruit bodies 2-5 cm wide.
Description: The nearly globose to hemispherical (but often
irregularly shaped) fruit bodies are grayish-white to pinkish-
brown at first. During these asexual stages the fungus releases
colorless spores called conidia which may appear whitish en
masse. With maturity, the fruit body becomes grayish-brown to
blackish. The surface of mature Carbon balls may appear finely
dotted (pimple-dotted) with minute bumps. These are the
openings of ascospore-forming structures called perithecia
located just below the surface. Black ascospores are
ejected from these openings in great numbers, covering the
surface of the fruit body and nearby surfaces. Numerous
concentric layers are revealed when Carbon balls are sliced
open.
Comments: Arora states that the common name "crampball"
refers to the "old folk belief that carrying one around under your
armpits would cure cramps!" Note the look-alike species in
Figure 5.

More information at TomVolkFungi.net:  

    

Figure 1. Mature specimens of Daldinia concentrica on
wood. Photo © Dianna Smith.


Figure 2. These pinkish specimens are in the asexual phase.
Note the concentric zonation of the cut open specimens in
the foreground. Photo © William Roody.

Figure 3. Another specimen of Daldinia concentrica.
Any doubt as to the identity of the specimen is removed
upon slicing the fruit body open to reveal the concentric
zonation. These concentric zones are not "growth rings."
An individual fruit body has only one period of active
ascospore discharge. Photo © Larry Grand.

Figure 4. The pimple-dotted surface of a mature Daldinia
concentrica. Each dot is the opening of an ascospore-
producing perithecium located just below the surface.
Photo © Gary Emberger.

Figure 5. A related species, Daldinia vernicosa, has a
narrowed, stemlike sterile base beneath the fertile portion.
The sectioned specimens at the right show the distinct
banding pattern of the sterile base. Photo © Steve Nelsen.