Trichaptum biforme

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
Fr.; Trichaptum pargamenum (Fr.) G. Cunn.;
Hirschioporus pergamenus (Fr.) Bondartsev & Singer
Common names:   Violet-toothed polypore.
Phylum:   Basidiomycota
Order:  Polyporales
Family:   Polyporaceae
Occurrence on wood substrate:  Saprobic; solitary to
overlapping clusters on dead deciduous wood, rarely on
conifers; year-round. 
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.
Edibility: Inedible.
Comments: A very colorful polypore when young. It can
occur in great numbers on the substrate. Compare to
Trichaptum abietinum which occurs almost always
on conifer wood and is generally smaller. Trichaptum
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   

Figure 1. This birch (Betula) tree is covered with
fruiting bodies of Trichaptum biforme. Photo © Gary

Figure 2. The violet coloration characteristic
of Trichaptum biforme is visible on the lower surface
of these specimens. Photo © Stephanie Depew.

Figure 3. 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 margins.
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
as 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
tooth-like pore surface even as the color fades on the cap
surface. Photo © Gary Emberger.

Figure 9. Much of the pore surface is brownish on these
older specimens. The violet coloration is restricted to the
margin. Photo © Larry Grand.

Figure 10. Tiny black club-like fungi are often present
on the upper surface of older Trichaptum biforme
fruitbodies. The little clubs are Phaeocalicium
, a saprobic ascomycete found only on
Trichaptum biforme.
Photo © John Plischke III.

Figure 11. A closer view of Phaeocalicium
on Trichaptum biforme.
Photo © John Plischke III.


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This page © 2008 by Gary Emberger, Messiah College