Scientific name: Camarops petersii (Berk. & M.A. Curtis)
Derivation of name: This fungus was first described in 1869
by Berkeley and Curtis from specimens collected by Judge
Thomas M. Peters (1810-1888) in Alabama, who is honored
by the specific epithet petersii.
Synonyms: Bolinia petersii (Berk. & M.A. Curtis) Lloyd;
Hypoxylon petersii Berk. & M.A. Curtis; Peridoxylon
petersii (Berk. & M.A. Curt.) Shear.
Common name(s): "Dog's nose fungus"
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.
ruptures to reveal the black, glistening, pimple-
of the stroma. The peridium eventually ends
up as a
ragged-edged ring of tissue around the periphery of
stroma. Many perithecia are embedded at various
within the stromatal tissue and the ostioles of their
terminate at the pimple-dots on the surface. Dark
exude from the ostioles (along with an exudate)
to form a wet,
shiny film on the surface of the stroma.
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 oak logs
quite eye-catching. Old records indicate American
chestnut was once a common habitat for Camarops
petersii before the demise
of the tree
as a prominent forest
species due to the chestnut blight fungus.
More information at MushroomExpert.com:
Figure 1. Camarops petersii on a barkless (decorticated)
Photo © Steve Nelsen.
Figure 2. The peridium is intact on the three small
Photo © John Plischke III.
Cluster of Camarops petersii on a decorticated
hardwood log. Photo © Dianna Smith.
Figure 4. Same cluster as Figure 3 but photographed three
months later in November. Photo © Dianna Smith.
Figure 5. This cluster of Camarops petersii was detached
from the wood and placed on the bark in order to take the
Photo © Dianna Smith.
Figure 6. The long dimension of this exceptionally large
specimen of Camarops petersii is 8.5 cm.
Photo © Gary Emberger.
Figure 7. The underside of the specimen in Figure 6.
Some of the wood substrate is attached to the specimen.
Photo © Gary Emberger.
Figure 8. The ruptured peridium reveals the shiny black
stroma beneath. Photo © Gary Emberger.
Figure 9. Close-up of a portion of Figure 8 showing the
peridium and the black, pimple-dot surface of the
stroma. Photo © Gary Emberger.
Figure 10. Longitudinal section of a young specimen of
Camarops petersii. The stroma is brownish and many
perithecia form at various depths within it. Photo © Gary
Close-up of a portion of Figure 10. The shiny
perithecial cavities are not yet filled with dark ascospores.
Note the long necks of the perithecia which connect to the
stromal surface. Photo © Gary Emberger.
Figure 12. Longitudinal section of an older specimen
the perithecia filled with dark ascospores and
liquid. Photo © Gary Emberger.