Scientific name: Trichaptum biforme (Fr.)
Derivation of name: Trichaptum means "with clinging
hairs"; biforme means "with two forms or stages" in reference
to the pore surface which can be either poroid or toothlike.
Synonymy: Polyporus biformis Fr. in Kl., Polyporus
pergamenus Fr.; Trichaptum pargamenum (Fr.) G. Cunn.;
Hirschioporus pergamenus (Fr.) Bondartsev & Singer
Common names: Violet-toothed polypore.
Occurrence on wood substrate: Saprobic; solitary to
overlapping clusters on dead deciduous wood, rarely on
Dimensions: Caps 1-7.5 cm wide and up to 3 mm thick.
Upper surface: White to grayish or brownish, greenish if
covered by algae; margin often purplish; zonate; hairy.
Pore surface: Purplish at first, fading to buff or brownish but
usually retaining violet tints near margin; poroid at first with
pores 2-5 per mm, becoming toothlike in age.
Comments: A very colorful polypore when young. It can
occur in great numbers on the substrate. Compare to
abietinum which occurs almost always
wood and is generally
subchartaceum (not illustrated) is a boreal species that
grows only on Populus spp. (aspen, poplar) and does
not develop a conspicupus tooth-like lower surface.
More information at MushroomExpert.com:
Figure 1. This birch (Betula) tree is covered with
fruiting bodies of Trichaptum biforme. Photo © Gary
The violet coloration characteristic
of Trichaptum biforme is visible on the lower surface
of these specimens.
Photo © Stephanie Depew.
The violet coloration is most vivid in the youngest
specimens as evidenced here. Photo © John Plischke III.
Figure 4. Zonate caps of young specimens of violet-toothed
polypore with intense
coloration along the cap
Photo © John Dawson.
Figure 5. Another example of the intense coloration possible
in young specimens. Photo © Pam Kaminski.
Figure 6. The tooth-like pore surface is quite evident here
is the overall violet coloration. Photo © Tom Volk.
Figure 7. The violet coloration of this species fades with
time. Here, the color is restricted to just the
margin of the
caps. On older specimens, the upper cap
surface may have
no violet color at all.
Photo © Tom Volk.
Figure 8. The violet coloration
remains longest on the
surface even as the color fades on the cap
surface. Photo © Gary
Figure 9. Much of the pore
surface is brownish on
older specimens. The violet coloration
Photo © Larry Grand.
Figure 10. Tiny black club-like fungi are often present
upper surface of
older Trichaptum biforme
The little clubs are Phaeocalicium
ascomycete commonly found
on Trichaptum biforme.
Photo © John Plischke III.
Figure 11. A closer view of Phaeocalicium
polyporaeum on Trichaptum biforme.
Photo © John Plischke III.