Daldinia concentrica

Scientific name:  Daldinia concentrica (Bolton) Ces. & De
Derivation of name:  Concentrica refers to the concentrically
zoned interior.
Common name(s):  Carbon balls; Crampballs; King Alfred's
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 of fungus tissue (i.e., stromal tissue) are
revealed when Carbon balls are cut vertically.
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 of the flesh. These concentric zones are not
"growth rings." An individual fruit body has only one
period of active ascospore discharge.
Photo © Gary Emberger.

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

Figure 5. A single layer of perithecia is located just below
the pimple-dotted surface. Photo © Gary Emberger.

Figure 6. Several carbon ball specimens were allowed to sit
on the paper plate and identification slip at the 2012 NEMF
foray. A zone of black spores formed around the central
specimen. See Figure 7. Photo © Gary Emberger.

Figure 7. The specimens in Figure 6 were removed to show
the black spore deposits. The black dots are spore deposits
that form very close to perithecial openings.
Photo © Gary Emberger.

Figure 8. 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.


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This page © 2008 by Gary Emberger, Messiah College